Hawthorn: The Definitive Guide

What is hawthorn?

Hawthorn refers to Crataegus species. Supplements may contain berries, leaves, flowers or mixed plant parts. Most heart-failure trials used standardized leaf-and-flower extracts rather than berry-only products.

WS 1442 is a dry ethanolic leaf-and-flower extract standardized to oligomeric procyanidins. Evidence for that named extract cannot be generalized to tea, tincture, whole berries or a product that lists only total milligrams.

Typical Hawthorn Protocols

No RDA, AI or UL exists for hawthorn. Trial protocols in diagnosed heart failure are not consumer dose recommendations.

Extract identity

Record the exact extract name, plant parts, drug-to-extract ratio and standardization. WS 1442 cannot be replaced by generic berry powder.

Frequency

HERB CHF used 450 mg twice daily. SPICE reported 900 mg/day in its results abstract without a per-administration schedule.

Background therapy

The major trials used hawthorn in addition to standard heart-failure treatment, not as a replacement.

Stopping

Do not change cardiac medicines or stop a studied adjunct without the prescribing clinician. Urgent symptoms need assessment rather than supplement adjustment.

What is hawthorn commonly used for?

Hawthorn is marketed for circulation, blood pressure, palpitations and “heart support.” The best-known research concerns adjunctive use of standardized leaf-and-flower extract in chronic heart failure. Those trials do not support self-treating undiagnosed symptoms or replacing guideline-directed therapy.

Older short trials reported improvements in exercise physiology and symptom scores. Larger contemporary trials gave a more cautious picture: no primary cardiac-event benefit in SPICE and no primary walking benefit in HERB CHF.

Which forms and labels matter?

Check the Latin species, plant part and extraction method. “Hawthorn 500 mg” does not reveal whether the product contains berry powder, leaf and flower, a tincture or a standardized dry extract. WS 1442 is standardized to 18.75% oligomeric procyanidins; products standardized only to flavonoids or with no marker are not equivalent.

Also record serving size versus per-capsule amount. Do not infer that two tablets per day means one morning and one evening unless the source states that schedule.

What does the human evidence show?

SPICE randomized 2,681 adults with NYHA II-III heart failure and reduced ejection fraction to WS 1442 900 mg/day or placebo for 24 months alongside standard treatment. The primary outcome, time to first cardiac event, was not significantly different: hazard ratio 0.95 with a 95% confidence interval of 0.82 to 1.10. A sudden-death finding in a subgroup was exploratory and does not reverse the neutral primary result. [1]

HERB CHF randomized 120 ambulatory adults on conventional medical therapy to WS 1442 450 mg orally twice daily or placebo for six months. Change in six-minute walk distance did not differ, and quality of life, functional capacity, neurohormones, oxidative stress and inflammation were also neutral. A secondary ejection-fraction difference favored hawthorn, but the authors cautioned against treating it as substantial evidence; adverse events were more frequent with hawthorn and mostly non-cardiac. [2]

The 2008 Cochrane review included 14 randomized double-blind placebo-controlled trials of hawthorn leaf-and-flower monopreparations. Ten trials involving 855 participants contributed pooled data. Maximal workload, exercise tolerance, pressure-heart-rate product and symptom scores favored hawthorn, but the studies were generally older and focused on surrogate or symptomatic outcomes. Relevant morbidity and mortality data were largely unavailable. [3]

How might hawthorn work?

Hawthorn extracts contain oligomeric procyanidins and flavonoids. Laboratory and animal work suggests effects on vascular tone, endothelial signaling, oxidative stress and myocardial function. These mechanisms depend on extract composition and do not prove fewer cardiac events.

A modest blood-pressure or heart-rate effect could interact with medicines or confuse symptom interpretation. Mechanistic plausibility is not a reason to delay established cardiovascular care.

What are the risks and interactions?

Reported effects include dizziness, nausea, gastrointestinal symptoms, headache, palpitations and rash. In HERB CHF, adverse events were significantly more frequent with hawthorn, though most were non-cardiac. Cardiac symptoms can also reflect the underlying disease, so attribution requires clinical review.

Hawthorn may add to the effects of antihypertensives, nitrates and other cardiovascular drugs. Digoxin concerns include possible pharmacodynamic interaction and interference with some assays. People using heart-failure, rhythm, blood-pressure or anticoagulant therapy should have the exact product reviewed by a clinician or pharmacist.

Pregnancy, breastfeeding and pediatric safety are not established. Seek urgent care for chest pain, fainting, severe breathlessness, new confusion, blue lips, rapid swelling or rapid weight gain.

Legal status in the United States and Canada

In the United States, hawthorn supplements are sold as dietary supplements and cannot be marketed as approved treatments for heart failure.

In Canada, licensed natural health products may carry product-specific authorized claims and conditions. A product licence does not make berry powder equivalent to WS 1442 or replace cardiac care.

What should be monitored?

Record extract, plant part, standardization, dose per administration, frequency, blood pressure, resting pulse, weight, ankle swelling, breathlessness, exercise tolerance, palpitations, dizziness and all medicine changes. Use the same measurement method and escalate worsening symptoms.

What happens after stopping?

No withdrawal syndrome or standard taper has been established for hawthorn. A clinician should direct changes when it is used with heart-failure treatment because symptoms and vital signs may reflect the disease or concomitant medicines.

How should hawthorn be stored?

Follow the product label, keep the original container closed and dry, preserve the lot and expiry information and keep it away from children.

Community experiences

Anecdotes often describe blood-pressure readings, palpitations or exercise tolerance without identifying plant part, extract or concurrent medicines. They can suggest what to track, but they cannot determine rhythm safety or prevent hospitalization.

How does hawthorn compare with other approaches?

Guideline-directed heart-failure treatment has outcomes evidence and structured monitoring. Hawthorn trials studied adjunctive use, and the largest trial did not reduce its primary cardiac-event endpoint. For blood pressure, established lifestyle and medication approaches have clearer dose, target and outcome frameworks.

Frequently asked questions

Is hawthorn berry the same as WS 1442?

No. WS 1442 is a standardized leaf-and-flower extract; berry powder is a different material.

Did SPICE show fewer cardiac events?

No significant benefit was found for the primary time-to-first-cardiac-event endpoint. [1]

Was 900 mg/day in SPICE taken once daily?

The results abstract reports the daily total but not the per-administration frequency. Do not label it once daily. [1]

What exact schedule did HERB CHF use?

WS 1442 450 mg orally twice daily for six months, added to standard therapy. [2]

Why did the Cochrane review look more favorable?

It pooled mostly older trials focused on symptoms and physiological measures. It did not establish fewer deaths or hospitalizations. [3]

Can hawthorn replace heart-failure medicine?

No. Major studies used it as an adjunct, and large contemporary trials had neutral primary outcomes.

Does hawthorn interact with digoxin?

Potential pharmacodynamic and assay concerns justify pharmacist or clinician review; do not self-adjust digoxin.

Glossary

Terms used in this guide.

WS 1442

A standardized dry ethanolic extract of hawthorn leaves with flowers used in multiple clinical trials.

Oligomeric procyanidins

Polyphenolic compounds used as a standardization marker for WS 1442.

NYHA class

A functional classification describing symptom limitation in heart failure.

LVEF

Left ventricular ejection fraction, an estimate of the proportion of blood pumped with each contraction.

Primary endpoint

The outcome designated in advance as the main test of a trial.

Adjunctive therapy

A treatment added to, rather than substituted for, standard care.

How this guide was researched

This draft prioritizes two named randomized trials and a Cochrane review. It separates daily total from administration frequency and keeps standardized leaf-and-flower extract evidence distinct from berry products. Evidence was updated October 9, 2026.

How this guide was made

The ledger preserves extract identity, plant part, amount per administration, daily total, frequency, duration, background therapy, primary outcome and correction status.

Sources

Related guides