Cagrilintide: The Definitive Guide

What is cagrilintide?

Cagrilintide is an experimental weight-loss medicine, given as a once-weekly injection, that copies amylin, a hormone that helps you feel full after eating. Novo Nordisk developed it. It is not approved anywhere yet, and it is best known as one half of CagriSema.

Amylin is made by the pancreas and released together with insulin after meals, and it signals fullness to the brain. An earlier amylin drug, pramlintide, has to be injected before every meal because it is cleared quickly. Cagrilintide is a lab-made amylin analogue built to last longer: a chain of 37 amino acids closely based on human amylin, with six swapped building blocks and a fatty-acid tail that lets it work for about a week. [1], [2], [3], [4]

The key word is investigational: it is still being tested, and no regulator has approved it. Unlike most peptides sold online, though, it has been studied in large randomized trials in people. Novo Nordisk has asked the FDA to approve CagriSema, its combination of cagrilintide and semaglutide (the drug in Wegovy and Ozempic), and a separate trial program is testing cagrilintide on its own. You may also see its development codes, AM833 and NNC0174-0833. [5], [6], [7], [8]

Typical Cagrilintide Protocols

The most common protocol in the reviewed sources is the trial schedule: 0.25 mg once weekly by subcutaneous injection, raised every 4 weeks through 0.5, 1.0 and 1.7 mg to a maintenance dose of 2.4 mg once weekly from week 17. Phase 3 trials used it for cagrilintide alone, and most dosing websites copy it. [9], [10], [11], [12], [13]

Titration Raising the dose in steps

The trial approach starts at 0.25 mg and moves up one step every 4 weeks. Investigators could delay a step or lower the dose when side effects were a problem, and 82.5% of people on cagrilintide alone were on the full 2.4 mg at week 68. The earlier dose-finding trial stepped up faster, every 2 weeks from 0.6 mg. [9], [8]

Breaks and cycles

The trials used cagrilintide continuously, without breaks, for 26 to 68 weeks. No study has tested cycling it on and off, so a break schedule is not established. [2], [9]

Read the units: cagrilintide amounts are written in milligrams (mg); 0.25 mg is the same as 250 mcg. Each number is the amount of cagrilintide itself. In CagriSema, "2.4/2.4 mg" means 2.4 mg of cagrilintide plus 2.4 mg of semaglutide, not 4.8 mg of cagrilintide.

Each row is a complete trial schedule: the high example is a shorter 26-week course, not a longer one at a higher dose. Low, mid and high are alternatives, not steps to move through. These are research schedules from trials of cagrilintide alone, not an approved label; the cited references give the full details. [2], [9]

Add-on schedules used with another weight-loss injection

In the online accounts and protocol pages reviewed, most people add a small amount of cagrilintide to semaglutide, tirzepatide or retatrutide, usually because hunger returns late in the week or weight loss has stalled. No human trial has tested cagrilintide with tirzepatide or retatrutide, so these schedules come from protocol websites, not studies. [14], [15], [16]

Community education groups describe the same low pattern most often: 0.25 mg once weekly, raised to 0.5 mg only if needed, often given 3–4 days after the weekly GLP-1-type injection. In public discussions, several people report strong fullness at these small doses when they are combined with another drug. [18], [19], [20]

Where protocols differ: dose size, step speed, timing, breaks and blends ↓

What is cagrilintide commonly used for?

People look into cagrilintide to lose weight, or to keep hunger under control while they do. Some are already on a GLP-1-type drug and want to quiet hunger that returns before the next weekly dose; a smaller group uses it to hold their weight after stopping another drug.

The trials show that cagrilintide alone lowers body weight more than placebo. They do not show how it performs at the low add-on doses most people use online, or alongside drugs other than semaglutide.

Weight loss on its own

This is the best-studied use. In a 26-week trial of 706 adults with overweight or obesity, average weight loss ranged from 6.0% at 0.3 mg to 10.8% at 4.5 mg, compared with 3.0% on placebo. In the 68-week REDEFINE 1 trial, the 302 people given cagrilintide 2.4 mg alone lost 11.5% on average, compared with 3.0% on placebo. [2], [9]

Averages hide a wide spread. In REDEFINE 1, about 57% of people on cagrilintide alone lost at least 10% of their weight, and about 14% lost at least 20%, if they kept taking it. [9]

Doserly

How much weight did people lose on cagrilintide alone?

Average percentage change in body weight from the start of the trial.

Phase 2 trial · 26 weeks · 706 adults without diabetes · one target dose each; doses from 1.2 mg reached in 2-week steps

Trial-product (if everyone kept taking the treatment).
Placebo −3.0%
Cagrilintide 0.3 mg −6.0%
Cagrilintide 0.6 mg −6.8%
Cagrilintide 1.2 mg −9.1%
Cagrilintide 2.4 mg −9.7%
Cagrilintide 4.5 mg −10.8%
Liraglutide 3.0 mg daily −9.0%
Separate groups, not steps: each dose was a different set of people.

REDEFINE 1 · 68 weeks · 3,417 adults without diabetes

Treatment-policy (everyone as randomized).
Placebo −3.0%
Cagrilintide 2.4 mg alone −11.5%
Semaglutide 2.4 mg alone −14.9%
CagriSema (2.4 mg + 2.4 mg) −20.4%
The 20.4% belongs to the combination, not to cagrilintide alone.

On its own, cagrilintide produced about 6–11% average weight loss in 26 weeks and 11.5% by 68 weeks; the larger CagriSema figure is a combination result.

Quieting hunger and "food noise"

Many people describe cagrilintide in terms of appetite: feeling full sooner, smaller portions and fewer intrusive thoughts about food, often called food noise. That fits amylin's role as a fullness signal. The downside is that some people struggle to eat enough, especially with another drug. The experience section covers both sides. [2], [21], [18], [19], [20]

Adding it to semaglutide, tirzepatide or retatrutide

Combining cagrilintide with semaglutide is the one combination that has been properly tested. In REDEFINE 1, CagriSema (2.4 mg of each) led to 20.4% average weight loss at 68 weeks, compared with 14.9% for semaglutide alone and 11.5% for cagrilintide alone. [9]

Pairings with tirzepatide or retatrutide are another matter. They are popular online, but neither has been tested in people; the published data on the retatrutide pairing come from a 2026 study in obese rats. The CagriSema result cannot simply be transferred to these combinations, or to the much lower add-on doses people use. [22], [15]

Blood sugar in type 2 diabetes

Two trials tested cagrilintide alone in people with type 2 diabetes. Over 32 weeks, HbA1c (a measure of average blood sugar over about three months) fell by 0.9 percentage points and weight by 8.1%. Over 68 weeks in REIMAGINE 2, HbA1c fell by 0.80 points and weight by 8.4%. In both trials the fall in blood sugar was smaller than with semaglutide or CagriSema; weight loss beat semaglutide's in the small 32-week trial but not in REIMAGINE 2. [23], [24], [25]

Other uses you may come across

Claims about protecting muscle, improving heart health or curbing alcohol cravings go beyond what has been shown for cagrilintide alone. In a REDEFINE 1 analysis, systolic blood pressure (the top number) fell by 5.2 points on cagrilintide alone versus 2.8 points on placebo, a smaller drop than with CagriSema. Body scans show how much of the weight lost was fat, not whether muscle was protected, and trials of bone and muscle effects are registered but have no results yet. [26], [27], [28], [29]

See the full trial results or how it works.

Where do cagrilintide protocols differ?

Trial schedules for cagrilintide are unusually clear. The disagreements start when people use it differently: at a fraction of the dose, on top of another drug, or for a few weeks instead of more than a year.

Is 2.4 mg the real dose, or 0.25 mg?

Both, in different situations. 2.4 mg once weekly is the maintenance dose in the phase 3 trials of cagrilintide alone and in CagriSema. 0.25 mg is the first step of that schedule, and it is the dose most add-on accounts describe. [9], [14]

The trial weight losses were measured at 2.4 mg or similar doses. They do not tell you what 0.25 mg a week adds to tirzepatide or retatrutide, because no study has tested that. A low add-on dose is a different use, not a milder version of the trials.

Doserly

How do trial dose steps compare with add-on doses?

Phase 3 schedule (REDEFINE 1; also phase 2 diabetes trial)

0.25 mg in weeks 1–4, 0.5 mg in weeks 5–8, 1.0 mg in weeks 9–12, 1.7 mg in weeks 13–16, then 2.4 mg from week 17.

Phase 2 top-dose group

0.6 mg in weeks 1–2, 1.2 mg in weeks 3–4, 2.4 mg in weeks 5–6, then 4.5 mg from week 7.

Common add-on range

0.25–0.5 mg a week alongside another weight-loss drug; not tested in trials.

Add-on doses are a fraction of trial doses, and they are combined with another drug.

Are the phase 2 doses a ladder to climb?

No. The 0.3, 0.6, 1.2, 2.4 and 4.5 mg doses in the phase 2 trial were separate groups: each person was assigned one target dose for the 26 weeks. People in the higher-dose groups stepped up every 2 weeks from 0.6 mg to reach it; nobody climbed through all five. Some websites list them correctly as separate regimens, while others turn them into a week-by-week escalation that the trial never used. [8], [30], [31], [32]

A few pages also stretch the highest group into a protocol, stepping from 0.6 mg to 4.5 mg every 2 weeks. That matches how the 4.5 mg group got there, but 4.5 mg was the highest dose tested, not a recommended target, and it added only about one percentage point over 2.4 mg (10.8% versus 9.7% at 26 weeks). [33], [34], [2], [9]

How fast should the dose go up?

The sources describe three speeds. The phase 3 trials stepped up every 4 weeks. The phase 2 trial stepped up every 2 weeks. Some add-on guides hold each step for "at least 2 weeks" or 2–4 weeks. [9], [8], [15]

The trial experience explains why slower steps are popular. In REDEFINE 1, where most people took CagriSema, nausea, vomiting and diarrhea were most common during the dose-raising weeks and eased afterward. Investigators were allowed to slow the climb or lower the dose, and many people on CagriSema stayed below the top dose. [9] Community education groups go further and describe starting as low as 0.1 mg and waiting 1–2 weeks before any increase.

Same day as the other injection, or midweek?

Add-on sources disagree. Some place cagrilintide on the day opposite the partner injection, to cover hunger that returns around days 4–6 of the week. Others give both on the same day at different sites, which matches how CagriSema is given. [14], [16], [15], [17], [35]

Neither timing has been compared in a study. With a half-life of about a week, cagrilintide does not clear between weekly doses; levels peak 1 to 3 days after each injection. Choosing the day mostly shifts when that peak falls in the week, and whether that changes results has not been tested. [36], [37]

Once weekly, split, or only as needed?

Trials used one injection a week. Some websites and community accounts split the weekly amount into two injections 3–4 days apart, hoping to blunt stomach upset; others use a dose only before events or on hard weeks. Splitting the same weekly total has not been shown to work better, and "as needed" use has no study behind it. [38], [16], [39], [40]

How long, and are breaks needed?

The trials ran continuously for 26 to 68 weeks, and one CagriSema trial ran for 84 weeks. Community education groups disagree sharply: some teach a short "bridge" of about 4–10 weeks, some describe 8–16 weeks on and 4–6 weeks off, and others set no limit. Protocol websites range from 8–24 weeks to ongoing use. [9], [41], [16], [15]

In the trials reviewed, planned breaks were never compared with continuous use. What is known about stopping is covered at the end of this section.

What about CagriSema and pre-mixed blends?

CagriSema contains equal amounts of both drugs, stepped up together. In trials, each drug started at 0.25 mg and rose every 4 weeks to 2.4 mg each; a lower 1.0 mg each dose has also been tested. Novo Nordisk's product is a dual-chamber pen, so the two drugs are kept apart until injection. [9], [24], [6]

Blends sold online are different products. Read their numbers carefully:

A fixed ratio also means you cannot change one drug without changing the other. In community education groups, members often describe first blend doses as too strong and suggest buying the two drugs separately. Read the Doserly guide to the CagriSema blend. [46], [47]

How do milligrams convert to syringe units?

Online cagrilintide usually comes as a powder that is mixed with sterile water. Syringe units on an insulin syringe measure volume, not an amount of cagrilintide, so the dose in each unit depends on how much water was added.

For example, 5 mg mixed into 2 mL gives 2.5 mg per mL, so 0.25 mg is 0.1 mL, or 10 units on a U-100 syringe. The same 0.25 mg from a 10 mg vial mixed into 2 mL is only 5 units. Doses this small leave little room for error: confusing "25 units" with "0.25 mg" can multiply a dose several times over, and community reports include accidental overdoses of this kind. Doserly's reconstitution calculator works out the arithmetic for any vial and shows each step. [15], [48], [49]

What happens when you stop cagrilintide?

The effect fades after the last dose, and some of the weight lost can come back. We found one published study that measured weight after cagrilintide alone was stopped, and it followed people for only 6 weeks. [2]

• The first weeks off treatment. In the phase 2 trial, treatment ended at week 26 and a check-up was scheduled 6 weeks later; 677 of the 706 participants attended. The authors reported "some weight regain" in the cagrilintide groups: across the five doses, the observed average weight loss was 6.1–10.8% at week 26 and 5.0–9.8% at week 32. [2], [115]
• Longer term. We found no longer-term result for cagrilintide alone. REDEFINE 1 followed everyone for 7 weeks after treatment, and its planned 97-week off-treatment extension includes only the CagriSema and placebo groups; we found no published weight results from either period. [9], [116]
• How long it stays in the body. With a half-life of about 7 to 8 days, cagrilintide takes several weeks to clear. The diabetes trial scheduled its safety visit 5 weeks after the last dose "to account for the long half-life" of the study drugs. [36], [117]
• Antibodies. People who still had antibodies to cagrilintide at the phase 2 trial's final visit could be retested up to 12 months later. We found no published results of those tests. [115]

Semaglutide, the drug combined with cagrilintide in CagriSema, has been tested directly. In STEP 4, people switched to placebo after 20 weeks regained 6.9% of their body weight over the next 48 weeks, while those who continued lost another 7.9%. In the STEP 1 extension, people had regained about two-thirds of the weight they lost within a year of stopping. These are semaglutide results; whether weight lost on an amylin drug returns the same way has not been tested. [118], [119]

In public discussions, former CagriSema trial participants describe hunger returning within weeks and regains of 10 to 30 lb in the months after their studies ended. We found no study comparing tapering down with stopping all at once, or showing that a break restores the effect. [42], [43], [105], [44]

How is cagrilintide taken, and how long does it last?

Cagrilintide is taken only by subcutaneous injection (into the fatty layer under the skin), once a week. In the trials, people injected it into the stomach area, thigh or upper arm with a pen. No pill, nasal spray or cream form of cagrilintide has been tested in people. [8], [9]

The fatty-acid tail is what makes weekly dosing possible. Its developers think it works by letting cagrilintide bind loosely to albumin, a common protein in the blood, which slows its removal, although they did not measure that binding directly. Its measured half-life, the time for blood levels to fall by half, was 159–195 hours (about 7 to 8 days), and levels peaked 1 to 3 days after an injection. [4], [36], [37]

Because each dose lingers, levels build up over the first weeks of weekly use, and an extra dose takes more than a few days to wash out. Some people describe hunger returning around days 5 to 6; that is a change in felt effect, not proof the drug has left the body. [36], [35], [58]

Do kidney or liver problems change the dose?

In two small single-dose studies of people with mild to severe kidney or liver impairment, blood levels of cagrilintide were similar to those in people with normal function, and the authors concluded that no dose adjustment was needed. These were one-dose studies of 33 and 32 people, and people on dialysis were excluded, so they say little about long-term use. [37]

Is a pre-filled pen the same as a vial sold online?

No. Trial participants used a manufactured pen with a known dose; CagriSema's pen keeps the two drugs in separate chambers. Online products are usually powders sold as "research use only", with no approved label, no guaranteed content and no instructions for people. FDA has sent warning letters to online sellers of these products. [9], [59], [60]

How should cagrilintide be stored, and how long does it last?

There is no approved label with storage instructions for people to follow. Trial sites used storage directions supplied by the sponsor, and the public record shows only this much:

• The trial product. Trials used a ready-made solution (10 mg per mL) in a pen cartridge, not a powder. It was to be used only if it looked "clear and almost colourless". Its storage conditions and in-use time were printed on the trial label and in a trial manual that has not been published, and sites had to report any temperature problem to the sponsor before the product could be used. [115], [117]
• The molecule. Natural amylin tends to clump into fibrils (sticky strands), which makes it hard to turn into a medicine. The developers changed several building blocks and added the fatty-acid tail to make "a chemically and physically stable molecule". That was a design goal tested in the laboratory, not a use-by date for any product. [4], [115]
• Powder sold online. These are unverified website claims, not tested instructions. Protocol websites claim the unmixed freeze-dried powder keeps frozen at about −20 °C or in the fridge, and that mixed (reconstituted) cagrilintide keeps in the fridge at 2–8 °C for 2 to 4 weeks, most often 28 to 30 days. Several say to throw away a solution that turns cloudy or contains particles. None cites a stability test of cagrilintide itself, and the trial product was a different, ready-made solution, so how long a mixed vial stays usable is not established. [54], [12], [30], [15], [34], [33]
• Shipping. FDA notes that injectable GLP-1 medicines need refrigeration as stated in their package inserts, and it has received complaints about compounded products arriving warm. Cagrilintide products sold online have no package insert. [75]

This guide does not cover mixing or injection technique; the Academy note below points to practical handling.

What do we actually know about cagrilintide in people?

Much more than for most peptides. Cagrilintide has been tested in randomized controlled trials involving thousands of people, and more than 1,000 of them received cagrilintide on its own. The complication is that most of the headline numbers belong to CagriSema, so it pays to check which group a result comes from. [2], [9], [24]

What did the trials of cagrilintide alone find?

Why are there two numbers for the same trial?

Trials often report two versions of the same result, called estimands. The "treatment-policy" number counts everyone as randomized, including people who stopped the drug. The "trial-product" number estimates what happens if everyone keeps taking it. That is why REDEFINE 1 reports 11.5% and 11.8% for cagrilintide alone, and 20.4% and 22.7% for CagriSema. Neither is wrong; they answer slightly different questions. [9]

The bigger risk is mixing up groups. CagriSema's figures, such as 13.7% in REDEFINE 2 (people with type 2 diabetes) and 20.4% in REDEFINE 1 (both counting everyone as randomized), belong to the combination. Some cagrilintide product pages lead with them anyway, so check which group any number comes from. [9], [62], [34]

What would a useful result look like in everyday life?

A trial average is not a prediction for one person. Results ranged widely, and the trials also measured things people notice day to day: waist size, blood pressure and physical function all improved with CagriSema in REDEFINE 1. A useful result might mean steady weight change while still eating enough, or hunger that stays manageable all week. [9]

That is why it helps to track more than weight. Appetite, energy, stomach symptoms and mood can move in different directions.

What don't the trials tell us?

• The way most people use it online. No human trial has tested low add-on doses, or cagrilintide with tirzepatide or retatrutide. [15]
• What happens after stopping. For cagrilintide alone, only a 6-week check after the last dose has been reported. REDEFINE 1's off-treatment extension includes only the CagriSema and placebo groups. [2], [116]
• Use beyond 68 weeks. Longer trials, including a large heart-outcomes trial of CagriSema, are still running. [63]
• Who was studied. About two-thirds of REDEFINE 1 participants were women, most were White, and few had a BMI below 30. [9]
• Children and adolescents. A trial is registered but has no results. [57]

How does cagrilintide work?

Cagrilintide copies amylin, one of the body's "you've eaten enough" signals, but lasts far longer. Where and how it acts comes mostly from cell and animal studies; the weight loss itself is established in human trials.

Which receptors does it switch on?

In cell studies, cagrilintide activates all three amylin receptors and the calcitonin receptor. That is why it is sometimes called a non-selective or dual amylin and calcitonin receptor agonist (an agonist is a molecule that switches a receptor on). Laboratory structures of cagrilintide bound to these receptors show it binds in a similar way to natural amylin. [4], [64], [65], [66]

The balance between the two receptor types is an active research question. In male mice missing two of the three amylin receptors, cagrilintide caused less weight loss, which suggests the amylin receptors do much of the work. [67]

Where in the brain does it act?

In rats and mice, cagrilintide acts on the brainstem, especially the area postrema and a nearby relay station called the nucleus of the solitary tract, which help control fullness and nausea. A 2026 study that mapped these brain cells across species found that silencing one group of brainstem cells in rats blocked cagrilintide's long-term effect on food intake and weight, but not semaglutide's. The human and monkey tissue in that study was used only to map the cells; no person received the drug. [68], [69]

Does it slow digestion?

In rats, repeated doses of cagrilintide slowed gastric emptying, the speed at which food leaves the stomach. People may differ: in a 62-person study, CagriSema cut how much people ate at a test meal by 63% but did not measurably slow gastric emptying, judged by how quickly a swallowed dose of paracetamol (acetaminophen) reached the blood. Full results for cagrilintide alone have not been published. [70], [71]

Why does it add to semaglutide?

Semaglutide acts on the GLP-1 receptor; cagrilintide acts on amylin and calcitonin receptors, partly through different brain cells. That fits the trial finding that the combination beat either drug alone, and similar extra effects appeared in rats. It is also why people try pairing cagrilintide with other GLP-1-type drugs, although pairings with tirzepatide or retatrutide have not been tested in people. [9], [72], [68], [22]

What about muscle loss?

Any large weight loss includes some lean tissue (muscle, organs and water) as well as fat. In a REDEFINE 1 body-scan subgroup, about two-thirds of the weight lost on CagriSema was fat and one-third lean mass. That result is for the combination. A 2026 conference presentation of the same subgroup reported that on cagrilintide alone, about 63% of the weight lost was fat and 37% lean soft tissue, which includes muscle but also organs and water. In rats, cagrilintide caused more lean-mass loss than a newer amylin drug at the doses tested, and a cell study found a short-lived drop in muscle-cell energy use that recovered within 5 days. A human trial of muscle effects is registered. [9], [27], [73], [74], [28]

What are the risks and unanswered questions?

Is cagrilintide safe?

It was generally tolerated in trials lasting up to 68 weeks, but it is not approved and long-term safety is not established. Those data also describe a pharmaceutical-grade product given under medical supervision, not powders bought online. [9], [24], [75]

The pattern of side effects is fairly predictable: stomach and bowel symptoms that become more common at higher doses, injection-site reactions, and fatigue at the highest doses. Rarer or slower-developing problems are harder to rule out. [2], [9]

What side effects did the trials find?

The clearest comparison comes from REDEFINE 1, where 302 people took cagrilintide 2.4 mg alone and 705 took placebo for 68 weeks. [9]

*From the sponsor's 2026 investor presentation; the other rows are from the published paper. [76]

In the phase 2 trial, stomach and bowel side effects affected 41–63% of people on cagrilintide versus 32% on placebo, rising with dose, and nausea affected 20–47% versus 18%. Fatigue was reported by 20 of 101 people on 4.5 mg, compared with 3 of 101 on placebo. [2], [8]

In REIMAGINE 2, in people with type 2 diabetes, the sponsor reported stomach and bowel events in 39.5% of people on cagrilintide alone versus 28.2% on placebo, and 4.6% versus 1.3% stopped treatment because of side effects. [25]

Some findings were reassuring. Mental-health questionnaires did not change meaningfully in any REDEFINE 1 group, heart rate fell slightly with cagrilintide alone (about 3 beats per minute) rather than rising, and the heart-rhythm study found no concerning changes. [9], [61]

What about antibodies to the drug?

Many people make anti-drug antibodies to cagrilintide. In the phase 2 trial, antibodies were detected at some point during 32 weeks in about half the people on lower doses and about three-quarters on 2.4 or 4.5 mg. Whether these antibodies reduce the drug's effect over time has not been clearly reported. [8], [2]

What problems do people report outside trials?

Public and community accounts describe the trial side effects plus a few that trials are too small to show clearly: severe fatigue, eating too little to meet protein or fluid needs, low mood or anxiety, immediate allergic reactions such as hives or swelling (community education groups describe a few similar cases), and dosing errors from mixing up syringe units and milligrams. The experience section describes them. These reports cannot show how often a problem happens or whether cagrilintide caused it; nearly all involve another drug and unverified products. [40], [19], [77], [78], [48]

Could product quality change the risk?

Yes. A correctly made drug and a particular vial bought online are separate questions. FDA has sent warning letters to at least three online sellers that marketed cagrilintide, calling the products unapproved new drugs despite "research" labels, and a fourth to a company that distributed cagrilintide as a bulk drug ingredient. A 2026 preprint that pooled test results for 14 peptides sold to consumers, including cagrilintide, found wide variation in purity and measurable endotoxin (a bacterial contaminant) in some samples, although it did not report cagrilintide separately. [59], [60], [79], [80], [81]

Is cagrilintide legal? Is it FDA-approved?

Checked September 23, 2026. Rules differ by country and change quickly.

United States. Cagrilintide is not an FDA-approved medicine, alone or in CagriSema.

• June 2025. FDA told state medical boards that cagrilintide does not qualify for compounding: it has no official monograph, is not part of an approved drug and is not on the lists of ingredients pharmacies may use. [82]
• December 18, 2025. Novo Nordisk submitted CagriSema to FDA for weight management. [5]
• September 2026. FDA's page on unapproved weight-loss drugs states that cagrilintide cannot be used in compounding under federal law and has not been found safe and effective for any condition. Novo Nordisk says CagriSema remains investigational, with an FDA decision expected in late 2026. [75], [6]

Canada. A submission for cagrilintide with semaglutide has been under Health Canada review since March 2026; it is not authorized for sale. In April 2026 Health Canada warned consumers about the risks of unauthorized injectable peptides bought online. [83], [84]

Australia. Cagrilintide is not on the Australian Register of Therapeutic Goods, which makes any product an unapproved therapeutic good; TGA says "research use only" disclaimers do not change that. In May 2026 TGA warned consumers about importing unapproved peptide products promoted online. Cagrilintide is not named in the June 2026 Poisons Standard. [85], [86], [87], [88]

Europe and the United Kingdom. Regulators have agreed plans for studying CagriSema in children, a routine step during development, but neither has approved it. [89], [90]

A "research use only" label does not make a product legal to sell for human use, and it does not make it safe.

Is cagrilintide banned in sport? Does it show up on a drug test?

Cagrilintide is not named on the World Anti-Doping Agency's 2026 Prohibited List or on the 2027 list that takes effect on January 1, 2027. However, WADA's category S0 bans, at all times, any drug with no current approval by a government health authority for human use, and cagrilintide has none; the 2027 list adds peptides to its examples. Tested athletes should treat it as prohibited, and should recheck if CagriSema is approved, because an approval could change how it is classified. [91], [92]

Anti-doping researchers have already mapped how cagrilintide breaks down in laboratory tests, the first step toward detection methods. How long it stays detectable after use has not been published. [93]

Does cagrilintide cause cancer or affect calcium and bones?

No cancer signal has been shown. In REDEFINE 1, confirmed cancers occurred in 0.7% of people on cagrilintide alone and 0.6% on placebo, and longer follow-up is still needed. [9]

The concern people raise is theoretical and comes from the calcitonin receptor. Calcitonin is a hormone that lowers blood calcium, and a salmon version used as a medicine for bone conditions carries a cancer warning: across 21 pooled trials, cancers were reported in 4.1% of people on it versus 2.9% on placebo, and Europe limited its long-term use in 2012. That finding is about a different drug. [94], [95]

Calcium is a related question. In a 2021 company conference abstract, single doses lowered blood calcium by 40–50% in young rats, but the effect faded with repeated dosing, was almost absent in older rats and stayed within the normal range in young dogs and rabbits. The authors wrote that clinical data showed this effect was not relevant in people, without showing those data. A trial of bone effects in people is under way. [96], [29]

Who should be especially cautious?

These groups have little or no safety data. That is a reason for caution, not proof of harm.

• Pregnancy and breastfeeding. No human data. In animal studies, cagrilintide caused major birth defects in rats and mice at exposures relevant to people, though not in rabbits, so the early trials excluded anyone who could become pregnant. [115], [117]
• People with diabetes on insulin or sulfonylureas. Cagrilintide lowers blood sugar modestly, and combining it with drugs that can cause low blood sugar needs medical oversight. [23], [3]
• A history of eating disorders or low body weight. Strong appetite suppression can make it hard to eat enough. [19]
• A history of depression or anxiety. Trial questionnaires showed no mood signal, but a few community accounts describe low mood. [9], [77]
• Upcoming surgery or procedures. Tell the surgical and anesthesia team about every weight-loss injection, including products bought online.
• Under 18. A trial in young people has no results yet. This guide is written for adults. [57]
• Competitive athletes. Covered by WADA's ban on unapproved substances. [91]

Does cagrilintide interact with other medicines?

Formal interaction data are limited. In a 20-week study, cagrilintide did not change blood levels or clearance of the semaglutide given with it. [36] Studies of cagrilintide with an oral contraceptive, and of CagriSema with atorvastatin and warfarin (a blood thinner), are registered without posted results. Poster titles at a 2026 obesity congress report no effect on the levels of those medicines, but the full data have not been published. The older amylin drug pramlintide slows stomach emptying and its label warns about timing some oral medicines, so it is worth asking about. Bring a complete list of everything you take, including other peptides, to a pharmacist or doctor. [97], [98], [99], [3]

What should be monitored while using cagrilintide?

There is no official monitoring plan, because cagrilintide is not an approved medicine and has no prescribing label. What exists is a record of what the trials checked, which shows what researchers were watching for. It can help you prepare questions for a clinician; it is not a personal testing plan. [115], [9]

What did the trials check?

• Weight and related measures. Body weight, waist size, blood pressure and pulse, blood fats (cholesterol and triglycerides), blood sugar measures such as HbA1c and fasting glucose, and C-reactive protein, a marker of inflammation. REDEFINE 1 also measured fat and lean mass with body scans (DXA) in a subgroup. [8], [120], [9]
• Safety checks. In the phase 2 trial of cagrilintide alone, these included physical examinations that covered the thyroid gland, ECGs, 24-hour blood pressure recordings, blood counts, liver and kidney tests, the pancreas enzymes amylase and lipase, calcium and phosphate, and hormones linked to calcium and fluid balance (calcitonin, parathyroid hormone, calcitriol, renin and aldosterone). Blood was tested for antibodies to the drug, and urine for protein and, where relevant, pregnancy. [115]
• Mood. Participants completed depression and suicidal-thoughts questionnaires (PHQ-9 and C-SSRS) throughout, and people with moderately severe depression symptoms or recent suicidal thoughts were not enrolled. In REDEFINE 1 the scores did not change meaningfully in any group. [115], [9]
• In people with type 2 diabetes. Trials counted low-blood-sugar episodes confirmed with a glucose meter, used continuous glucose monitors, and required an eye examination for diabetic retinopathy (diabetes-related damage to the back of the eye) before entry. [117], [10], [121]

Which signals matter, and why?

[9], [2], [8], [115], [96], [26], [77]

Anyone taking cagrilintide with semaglutide or another GLP-1 medicine is also covered by that medicine's label, which has its own checks: symptoms of pancreatitis and gallbladder disease, low blood sugar with insulin or sulfonylureas, kidney problems from dehydration, heart rate, and eye complications in people with type 2 diabetes. The older amylin drug pramlintide carries a boxed warning for severe low blood sugar when used with insulin. Which checks make sense for you is a question for a clinician. [122], [3]

What do people in public communities report?

Public discussions come from two groups: trial participants, often unsure which treatment they received, and people buying it online, who mostly add it to retatrutide or tirzepatide. Only a handful of accounts describe cagrilintide on its own, so most stories cannot separate its effect from the other drug. [100], [21]

What do the positive reports look like?

The most common positive story is about hunger. One forum member said cagrilintide "really killed my food noise" within two weeks, at a dose written as "0,25" with no unit. Another, using about 1.25 mg on its own every 7 to 10 days after earlier tirzepatide and retatrutide, said nothing takes the food noise away quite like it, without the tiredness others describe. A person on retatrutide added a dose written as ".5", again without a unit, and wrote that they had never been so full. [18], [21], [101]

Trial participants describe larger weight losses, such as 62 lb over about a year in REDEFINE 1, but they were usually blinded and could have been on semaglutide, cagrilintide, the combination or placebo. [102], [44]

How long did the effect last?

Follow-ups often change the picture. Several people describe a strong start that faded: one on retatrutide said cagrilintide was "fantastic at first" and hardly noticeable four to five months later, even at 2 mg. Others describe the effect wearing off within the week, with hunger returning around days 5 or 6. [103], [35], [104]

Stopping is a recurring theme among former trial participants, who describe hunger returning within weeks and regains of 10 to 30 lb in the months after their studies ended. [42], [43], [105]

Does everyone notice a difference?

No. Some people notice little or nothing. One forum member reported no effect on two attempts, stepping up as far as 4.5 mg with products from different sources. Others describe no change at 0.25–0.5 mg that only appeared at 1 mg, or continued "food noise" at 1 mg with retatrutide. [106], [107], [108], [109]

A disappointing response does not by itself prove a product was weak or the dose too low. Unit mistakes, product quality, eating patterns and the other drug all play a part, and the trials show a wide range of responses even with a known product. [9]

What about unwanted effects?

Fatigue is the complaint that stands out, more than nausea. Descriptions range from being "seriously tired" with brain fog after 250 mcg to "extreme fatigue" lasting a couple of months; in another account, energy came back after stopping. Stomach effects include vomiting after a first 0.5 mg dose, severe bloating and constipation. A few people describe low mood, anxiety or loss of interest. One person, who was also taking retatrutide and other peptides and had a history of similar reactions, had hives, itching and flushing after a first 0.25 mg dose and went to an emergency department. [110], [40], [103], [49], [111], [112], [77], [78]

Community education groups report the same themes, including fatigue as the most common complaint, over-suppressed appetite and a small number of immediate allergic reactions. Educators in those groups disagree about the drug itself: some discourage it for most people, some allow it only as a short bridge, and some present long-term use. The risks section covers what the trials measured.

How can you judge a weight-loss story?

Useful questions to ask: Was it cagrilintide alone, or with another drug? What dose, and was it measured in milligrams or syringe units? How long had the person been on the other drug, and did its dose change at the same time? Were they also eating much less, or exercising more? What happened after stopping?

Selected discussions help identify experiences and questions that research should examine. They are not a survey of all users, a response rate or a substitute for the controlled trials described above.

How does cagrilintide compare with semaglutide, CagriSema, petrelintide and zenagamtide?

These are the medicines most often weighed against cagrilintide. Cagrilintide and petrelintide are amylin analogues (cagrilintide also acts on the calcitonin receptor), semaglutide copies the gut hormone GLP-1 only, and CagriSema and zenagamtide act on both: CagriSema as two drugs in one pen, zenagamtide as a single molecule. Status was checked on September 23, 2026.

The weight results come from separate trials in different people, and they use different ways of counting people who stopped, so the table cannot rank these medicines. Cagrilintide alone and semaglutide alone have been compared inside the same trials: in REDEFINE 1, in adults without diabetes, cagrilintide alone led to less average weight loss than semaglutide alone (11.5% versus 14.9%), while in a small 32-week trial in type 2 diabetes it led to more (8.1% versus 5.1%), and in REIMAGINE 2 it did not beat semaglutide. We found no trial comparing cagrilintide alone with petrelintide or zenagamtide. Two other amylin drugs come up in the same discussions: pramlintide (Symlin), approved in the United States since 2005 for diabetes and injected at meals alongside insulin, and eloralintide, an experimental once-weekly injection from Eli Lilly, with up to 20% average weight loss at 48 weeks versus 0.4% on placebo in a phase 2 trial. Each guide covers its own doses, risks and legal status. [9], [23], [25], [3], [128]

Common questions about cagrilintide

How long does cagrilintide take to work?

People often notice fuller-feeling meals within days, but weight loss builds over months. In separate trials, cagrilintide 2.4 mg alone produced about 9.7% average loss by 26 weeks and 11.5% by 68 weeks. Community reports of appetite changes within hours or days mostly involve another drug as well. [2], [9], [113] See how the trial schedule works.

Is cagrilintide the same as CagriSema?

No. Cagrilintide is one drug. CagriSema is Novo Nordisk's combination of cagrilintide and semaglutide in equal doses, given together once a week. CagriSema produced about 20% average weight loss in REDEFINE 1; cagrilintide alone produced about 11.5%. [9] Read the Doserly guide to the CagriSema blend and to semaglutide.

Is cagrilintide a GLP-1? Is it the same as pramlintide?

It is neither. Cagrilintide is an amylin analogue, not a GLP-1 drug like semaglutide or tirzepatide; it acts on amylin and calcitonin receptors. Pramlintide is an older, short-acting amylin analogue approved in the United States in 2005 for diabetes and injected before meals alongside insulin. Cagrilintide was designed for one injection a week instead. [64], [9], [3]

Can you take cagrilintide with retatrutide or tirzepatide?

People do, but it has not been tested in people. The only combination tested in people is CagriSema, with semaglutide. Websites describe adding 0.25–0.5 mg a week, or copying the trial steps up to 2.4 mg, and community accounts report both stronger appetite control and more fatigue and stomach upset. The retatrutide pairing has been studied only in obese rats, in a 2026 paper. [14], [15], [22], [114] See add-on schedules.

What happens when you stop cagrilintide?

Some weight is likely to come back, but for cagrilintide alone only a short follow-up exists: in the phase 2 trial, the observed average weight loss across doses went from 6.1–10.8% at the last dose to 5.0–9.8% six weeks later. No longer-term result has been published. Former CagriSema trial participants describe hunger returning within weeks and weight regain of 10 to 30 lb in the following months. [2], [42], [43], [105] See what happens when you stop.

How much weight do people lose on cagrilintide alone?

On average, 6.0–10.8% of body weight over 26 weeks in the phase 2 trial and 11.5% over 68 weeks at 2.4 mg in REDEFINE 1, compared with about 3% on placebo. In type 2 diabetes the averages were about 8%, and individual results varied widely. [2], [9], [23] See the trial results.

Is it legal to buy cagrilintide?

It is not approved anywhere, and FDA says US pharmacies cannot compound it. Products sold online as "research use only" are not approved for human use, and FDA has issued warning letters to several sellers. Rules differ by country. [75], [59] See the dated legal-status summary.

Does cagrilintide cause muscle loss?

Some lean-mass loss happens with any large weight loss. In a REDEFINE 1 subgroup on CagriSema, about one-third of the weight lost was lean mass. For cagrilintide alone, a 2026 conference presentation reported about 37% of the weight lost as lean soft tissue, which is not the same as muscle, and a registered trial is studying muscle directly. [9], [27], [28] See what about muscle loss.

Glossary

Plain explanations of the route, dosing and research terms used in this guide. Underlined terms in the text link here.

Adverse event

A harmful or unwanted medical event reported after someone used a treatment. A report alone does not prove the treatment caused it.

Amino acid

A small chemical building block. Chains of amino acids make up peptides and proteins.

Amylin

A hormone released by the pancreas together with insulin after meals. It helps signal fullness and slows how fast food leaves the stomach.

Amylin analogue

A lab-made molecule designed to act like amylin. Cagrilintide and pramlintide are examples.

Animal study

Research in animals such as rats or mice. It shows what a substance does in a living body, but results in people can differ.

Anti-drug antibodies

Antibodies the immune system makes against a medicine. Some have no noticeable effect; others can reduce how well the medicine works.

Blend

A product that combines cagrilintide with another drug, such as semaglutide or retatrutide. The blend's total amount is not its cagrilintide amount.

CagriSema

Novo Nordisk's investigational combination of cagrilintide and semaglutide in equal doses, given once weekly.

Amylin and calcitonin receptors

Switches on cells that respond to amylin and to calcitonin, a hormone involved in calcium balance. The three amylin receptors are built from the calcitonin receptor plus a partner protein. Cagrilintide activates all of them.

Cell study (in vitro)

Research on cells grown in a dish. It gives early clues about biology, but it is far from proof of benefit in people.

Compounding

When a pharmacy prepares a customized medicine from individual ingredients. In the US, federal rules control which bulk ingredients pharmacies may use.

Controlled trial

A study that compares people who receive a treatment with a similar group who do not, often receiving a placebo instead. Randomly assigning people to each group makes the comparison fairer.

Course and cycle

A course is the period of repeated use, such as 16 weeks. A cycle is a course plus a planned break before any further use.

Dose (amount each time)

The amount given on one occasion. A protocol lists both the dose and how often it is given.

DXA scan

Dual-energy X-ray absorptiometry, a low-dose X-ray scan that measures fat, lean mass and bone separately. Trials use it to see what kind of weight was lost.

ECG

Electrocardiogram, a recording of the heart's electrical activity taken with sensors on the skin. It shows heart rate and rhythm.

Estimand

The exact question a trial result answers. A treatment-policy result counts everyone as assigned, including people who stopped; a trial-product result estimates what happens if everyone keeps taking the drug.

Food noise

An informal term for frequent, intrusive thoughts about food and eating. It is not a medical measurement.

Freeze-dried (lyophilized)

A powder made by freezing a solution and removing the water. Peptides sold online usually come this way and must be mixed with sterile water before injection.

Gastric emptying

How quickly food leaves the stomach. Slower emptying can make people feel full sooner and can change how fast some tablets are absorbed.

GLP-1 drugs

Medicines such as semaglutide that act on the GLP-1 receptor to reduce appetite and lower blood sugar. Tirzepatide and retatrutide also act on other hormone receptors. Cagrilintide is not a GLP-1 drug.

Half-life

The time it takes for the measured level of a substance in the blood to fall by half. It is not the same as how long an effect lasts.

HbA1c

A blood test that reflects average blood sugar over roughly the previous three months. It is the main measure in diabetes trials.

Investigational

Still being studied and not approved by a regulator, such as the FDA, to treat any condition.

Lean mass

Everything in the body that is not fat, including muscle, organs, bone and water. Body scans measure it separately from fat.

mcg and mg

Micrograms and milligrams. 1 mg equals 1,000 mcg, so 0.25 mg is 250 mcg. Cagrilintide amounts are usually written in mg.

New Drug Application (NDA)

A company's formal request for FDA approval of a new medicine. Filing an application is not the same as approval.

Peptide

A short chain of amino acids. Cagrilintide is a chain of 37 with a fatty-acid tail attached.

Pharmacokinetics

How the body absorbs, moves, breaks down and removes a substance.

Trial phases

Stages of testing in people. Phase 1 checks safety and blood levels, phase 2 tests doses in patients, and phase 3 confirms benefits and harms in large groups before approval.

Placebo

A dummy treatment with no active ingredient, used as a comparison in studies.

Preclinical research

Studies done before research in people: cell studies and animal studies.

Reconstitution

Mixing a freeze-dried powder with sterile water to make an injectable solution. The amount of water sets how much drug each syringe unit holds.

Research use only

A label on products sold for laboratory research. It does not mean a product is approved, tested for human use or legal to sell as a medicine.

Subcutaneous (SC)

Injected into the fatty layer just under the skin. This is the route used in every cagrilintide trial.

Syringe units

Markings on an insulin syringe that measure volume. On a U-100 syringe, 100 units equal 1 mL. The amount of drug per unit depends on the vial's concentration.

Titration and maintenance dose

Titration means raising a dose in steps, usually to reduce side effects. The maintenance dose is the amount kept once the steps are finished, such as 2.4 mg in the cagrilintide trials.

WADA

The World Anti-Doping Agency, which publishes the list of substances banned in sport. Its category S0 covers drugs not approved for human use anywhere.

Weekly total

All the amounts given in one week, added together. For example, 0.25 mg twice weekly is a 0.5 mg weekly total.

Explore more of the research

Go deeper into the laboratory and animal experiments behind the claims. Across this guide, the citations include 25 original scientific papers: 14 reports of human studies and 11 laboratory, cell, structural or animal papers, plus company conference abstracts that are labeled as such. Paper counts are not counts of independent research teams: most cagrilintide research is sponsored or carried out by Novo Nordisk.

How this guide was researched

This guide is built from a thorough review of the sources cited throughout it: published clinical trials, registered study plans, regulatory documents, laboratory and animal research, and published protocol descriptions. We also reviewed public online forums and community education groups where people describe their own experiences with cagrilintide.

The guide cites 128 sources, including 25 original scientific papers. Each type of source answers a different question. Trials show what researchers measured. Protocol descriptions show how cagrilintide is typically used outside trials. Personal accounts show what individual people experienced. Every numbered citation links to its entry below, labeled by source type.

How this guide was made

Research and drafting were AI-assisted. Every cited source was checked against the original, and the guide was reviewed and edited by Doserly before publication. It has not had an independent clinical review, and Doserly does not currently have medical reviewers. Doserly makes a medication and health-tracking app and runs Doserly Academy, both of which are promoted in this guide. Read our editorial policy for how guides are researched, updated and corrected.

This guide is for educational purposes. It summarizes what the reviewed sources report so the research is easier to understand; it is not medical advice. For a deeper dive, or to check any point for yourself, go straight to the cited sources.

Explore the sources