In this guide
What is Glutathione?
Glutathione is a tripeptide made from glutamate, cysteine and glycine and used in cellular redox systems. Raising a blood or cell-store biomarker does not establish detoxification, disease treatment, immune protection or durable skin lightening. The WHO indispensable-amino-acid table assigns no adult dietary requirement to this compound; it therefore supplies no supplement target. [1]
Typical Glutathione Research Protocols
| Source and population | Form and amount per administration | Frequency | Total exposure | Duration or window |
|---|---|---|---|---|
| Richie 2015 · 61 enrolled, 60 treated, 54 analyzed healthy nonsmokers | Reduced glutathione 125 mg × 2 capsules or 500 mg × 2 capsules | Two capsules per day; whether together or divided was not reported in the methods read | 250 or 1,000 mg/day | 6 months, then 1-month washout |
| Arjinpathana 2012 · 60 healthy medical students | Glutathione 250 mg per administration | Twice daily on an empty stomach | 500 mg/day | 4 weeks |
These rows reproduce studies. Do not average their populations, forms, frequencies or durations into one regimen.
From dietary requirement to claim
Units, mixture, timing and endpoint stay attached to their source.
Should Glutathione be cycled?
No verified trial establishes a cycle. A review point can limit indefinite use, but it does not prove a physiological reset.
What happens when it is stopped?
No withdrawal syndrome is established. An acute or short study cannot predict persistence after stopping.
Which foods provide it?
Foods contain glutathione and its amino-acid precursors, while the body synthesizes and recycles glutathione. Food intake, ordinary reduced glutathione, oxidized glutathione, liposomal products and intravenous products are not interchangeable exposures. [1]
Which forms and label details matter?
Record reduced glutathione (GSH), oxidized glutathione (GSSG), liposomal formulation or another delivery system, plus actual glutathione per administration. GlyNAC, NAC and cysteine are precursors or combinations with different evidence. Intravenous exposure is a separate medical and safety context.
How should it be stored?
Follow the finished-product label, close the container and protect it from moisture and heat. Keep the lot number and discard a product with a broken seal or unexplained change.
What is Glutathione commonly used for?
Oral glutathione is marketed for antioxidant status, immunity, detoxification and skin lightening. A longer trial measured body-compartment glutathione rather than clinical health outcomes. Skin studies are short, small and inconsistent across body sites.
What does human research show?
Richie enrolled 61 healthy nonsmokers, treated 60 and analyzed the 54 who completed at least six months: 16 placebo, 18 at 250 mg/day and 20 at 1,000 mg/day. Two capsules daily for six months increased glutathione in several measured compartments, most consistently at the higher exposure, and many changes moved toward baseline during a one-month washout. Immune-marker analyses used smaller subsets. The study shows product-specific biomarker uptake, not detoxification or disease prevention, and Kyowa Hakko supplied the Setria product. [2] Dilokthornsakul's skin review included four studies: three placebo-controlled RCTs and one single-arm study, using oral 250–500 mg/day or topical GSSG. Findings differed by sun-exposed versus protected sites and were inconsistent; the authors called the evidence inconclusive. [3] Arjinpathana randomized 60 healthy students to 250 mg twice daily on an empty stomach or placebo for four weeks. All completed; melanin index favored glutathione at only two of six measured sites. The study was short and did not establish durability or long-term safety. [4]
How might it act?
Glutathione participates in peroxide reduction, electrophile conjugation and redox signaling, cycling between reduced and oxidized forms. Oral products may supply intact glutathione or amino-acid components depending on formulation and digestion; a compartment concentration is not a direct clinical outcome.
What are the risks and interactions?
Oral trial safety is limited by sample size and duration; GI symptoms or hypersensitivity remain possible. Do not transfer oral evidence to intravenous glutathione, which has different exposure and documented serious safety concerns in cosmetic use. Asthma, pregnancy, breastfeeding, cancer treatment, kidney or liver disease and use of chemotherapy or other redox-active treatment require clinician review. Skin-lightening use also raises product-quality and inequitable-colorism concerns.
Which medicines can interact?
Product-specific interaction data are limited. Have the complete formula reviewed by a pharmacist when taking medicines, especially for neurologic, psychiatric, metabolic, kidney or liver conditions. Do not invent a universal separation interval.
Regulatory status: In the United States, supplements are not routinely approved for efficacy before sale. In Canada, check the NPN or DIN-HM and licensed label conditions. [5], [6]
What should be monitored?
Record product, lot, form, amount per administration, frequency, daily total, co-ingredients, dietary context, symptoms and intended outcome. Set a review date before starting.
Stop and seek advice for an allergic reaction, persistent vomiting, unusual weakness, confusion or another severe symptom.
What do public communities report?
Public discussions often emphasize taste, timing and felt effects while omitting lot, total diet and validated outcomes. This update did not independently recrawl or quantify those posts.
How does Glutathione compare?
| Option | What it supplies | Limit |
|---|---|---|
| Glutathione | One defined amino acid | Does not replace complete protein |
| EAAs | All nine indispensable amino acids | Formula varies |
| BCAAs | Leucine, isoleucine and valine | Six EAAs are absent |
| Complete protein | All EAAs in a protein matrix | Portion and digestibility vary |
Common questions about Glutathione
Does oral glutathione detox the body?
That claim is not established by trials measuring blood or cell glutathione concentrations.
Does it lighten skin reliably?
Evidence is inconclusive, site-specific and short-term; durability and long-term safety are not established.
Is liposomal glutathione equivalent to ordinary GSH?
No. Delivery systems can change exposure, so each formulation needs its own evidence.
Is NAC the same as glutathione?
No. NAC is a cysteine donor and precursor with different clinical evidence.
Can oral evidence support IV injections?
No. Intravenous exposure has different risks and should never inherit oral supplement findings.
What should I track?
Record reduced/oxidized form, delivery system, amount per administration, frequency, product lot, intended clinical outcome, adverse effects and review date.
Glossary
Plain terms for interpreting the evidence.
- Indispensable amino acid
- An amino acid the diet must provide.
- Dietary requirement
- Total required intake; not a supplement dose.
- Amount per administration
- Amount consumed at one time, distinct from daily total.
- NOAEL
- Highest tested level without an observed adverse effect in one study; not automatically a UL.
- UL
- Tolerable Upper Intake Level established by an authority.
- Biomarker
- Biological measure that is not necessarily a felt or clinical benefit.
How this guide was researched
The complete WHO report, accessible primary human studies and live NCBI metadata were read on October 9, 2026. Titles, authors, journals, DOI, PMID, available PMCID and CommentsCorrections were checked. Open full text supplied methods details; an unreported frequency was not guessed. [1], [2], [3], [4], [5], [6]
How this guide was made
Research and drafting were AI-assisted. This draft awaits Doserly editorial review and independent clinical review. See the editorial policy.
Explore the sources
Sources preserve form, dose, frequency, population, duration and outcome.
Showing 6 sources
- 01
Protein and amino acid requirements in human nutrition: report of a joint WHO/FAO/UNU expert consultation ↗
Official expert report
Current primary source and identity checked; limitations are retained in the text.
Detail: Glutathione is a tripeptide synthesized from glutamate, cysteine and glycine; WHO Table 49 does not assign it an adult dietary requirement.
- 02
Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. ↗
Six-month randomized biomarker trial
Current primary source and identity checked; limitations are retained in the text.
Detail: 61 enrolled, 60 treated and 54 analyzed; 250 or 1,000 mg/day as two capsules for six months, then one-month washout.
- 03
The clinical effect of glutathione on skin color and other related skin conditions: A systematic review. ↗
Systematic skin review
Current primary source and identity checked; limitations are retained in the text.
Detail: Four studies; oral 250–500 mg/day or topical oxidized glutathione; inconsistent findings and inconclusive evidence.
- 04
Glutathione as an oral whitening agent: a randomized, double-blind, placebo-controlled study. ↗
Small randomized skin trial
Current primary source and identity checked; limitations are retained in the text.
Detail: 60 completed; 250 mg twice daily on an empty stomach for four weeks; between-group significance at two of six sites.
- 05
Questions and Answers on Dietary Supplements ↗
U.S. regulatory overview
Current primary source and identity checked; limitations are retained in the text.
Detail: Dietary supplements are not routinely FDA-approved for efficacy before sale.
- 06
Product Licensing ↗
Canadian licensing overview
Current primary source and identity checked; limitations are retained in the text.
Detail: Canadian authorization attaches to the licensed finished product and label conditions.
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