Hawthorn

botanicalprocyanidin B2

What is it

Hawthorn (Crataegus species, most commonly C. monogyna, C. laevigata, or C. pinnatifida) is a thorny shrub or small tree whose leaves, flowers, and berries are used in traditional and modern herbal medicine, primarily for cardiovascular support.

How it works

Hawthorn contains a complex mixture of bioactive compounds, including oligomeric proanthocyanidins (OPCs), flavonoids (such as vitexin, rutin, and hyperoside), and triterpene acids. These constituents are thought to exert effects on the cardiovascular system through multiple mechanisms. Proposed mechanisms include mild positive inotropic effects (improving heart muscle contractility), vasodilation through inhibition of angiotensin-converting enzyme and direct effects on smooth muscle, and antioxidant activity that may protect cardiovascular tissues. Hawthorn extracts have been shown in laboratory studies to increase coronary blood flow and reduce arrhythmia risk in animal models. The most-studied indication is mild to moderate heart failure (NYHA class I-II), where standardized hawthorn extracts (such as WS 1442, used in European products) have been added to standard therapy in clinical trials. Effects on healthy individuals or those with mild blood pressure changes are less well established.

Evidence for 4 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Mild to moderate heart failure (NYHA class I-II)

Grade B

Good evidence

Multiple controlled trials of standardized hawthorn extract WS 1442 show modest improvements in exercise tolerance, symptom scores, and ejection fraction when added to standard heart failure therapy. A large mortality trial (SPICE) showed no overall mortality benefit.

Mild hypertension

Grade C

Moderate evidence

Some trials suggest modest reductions in blood pressure with hawthorn extract over 8 to 12 weeks, particularly in those with mild elevations. Effect sizes are small and not consistently demonstrated.

Angina symptom relief

Grade D

Mixed evidence

Limited evidence suggests possible modest improvement in angina symptoms with chronic hawthorn use. Not appropriate as primary therapy.

Anxiety and palpitations

Grade D

Mixed evidence

Some traditional use and small trials suggest hawthorn may help with palpitations related to mild anxiety. Evidence is preliminary.

4 commercial forms

WS 1442 standardized extract

Standardized to 18.75% oligomeric procyanidins

Most-studied form, used in European heart failure trials. Sold under various brand names internationally.

Hawthorn berry extract

Higher procyanidin content than leaf

Common in supplements. Often standardized to procyanidin or flavonoid content.

Hawthorn leaf and flower extract

Traditional European preparation

Used in many European phytomedicine products.

Liquid extract / tincture

Alcohol-based extraction

Used in traditional and modern herbalism.

Dosage

There is no established RDA. Traditional dried leaf-and-flower or berry preparations use 1.5 to 3.5 grams per day, often as a tea. Standardized extracts (such as WS 1442, standardized to 18.75 percent oligomeric procyanidins) are commonly studied at 160 to 1,800 mg per day, divided into two doses. Most clinical heart failure trials used 900 mg per day. Effects typically require 6 to 12 weeks of consistent use.

When and how to take it

Hawthorn can be taken with or without food. Standardized extracts are typically dosed twice daily, morning and evening. Effects on cardiovascular markers and symptoms usually emerge gradually over 6 to 12 weeks of consistent use. There is no strong evidence for a specific time-of-day preference. Take consistently at the same times each day.

Safety

Hawthorn is generally well tolerated. The most common side effects are mild and include nausea, dizziness, headache, and palpitations. Allergic reactions are rare. A large clinical trial (SPICE) in patients with heart failure did not show net mortality benefit and raised some concerns about increased early sudden cardiac death in a subgroup, prompting cautious interpretation. There is no established Tolerable Upper Intake Level.

Who should be cautious

People with diagnosed heart failure or cardiovascular disease should use hawthorn only under cardiology supervision, not as a substitute for prescribed therapy. Those on cardiac medications including digoxin, antihypertensives, or nitrates need medical guidance. Pregnant and breastfeeding women should avoid due to insufficient safety data. Discontinue at least two weeks before scheduled surgery. Not appropriate for self-treatment of suspected heart conditions.

Interactions

Hawthorn may potentiate the effects of digoxin and other cardiac glycosides, requiring monitoring and possible dose adjustment. It may have additive effects with antihypertensive medications, potentially causing low blood pressure. Possible interactions with beta-blockers, calcium channel blockers, and nitrates warrant medical supervision. Combined use with anticoagulants may modestly affect platelet function.

Frequently asked questions

Can hawthorn replace my heart medication?⌄

No. Hawthorn is not a substitute for prescribed cardiovascular medications. It has been studied as an adjunct to standard therapy in heart failure, but stopping prescribed medication without medical guidance can be dangerous.

How long until I see effects from hawthorn?⌄

Clinical effects typically emerge gradually over 6 to 12 weeks of consistent daily use. Acute effects from single doses are minimal.

Is hawthorn safe with digoxin?⌄

Hawthorn may potentiate digoxin's effects, raising the risk of digoxin toxicity. Only use this combination under cardiology supervision with appropriate monitoring.

Which part of the hawthorn plant is best?⌄

European standardized extracts often combine leaf and flower (e.g., WS 1442). Berry extracts are common in North America. The most extensive clinical evidence comes from leaf-and-flower standardized extracts.

Can hawthorn help with high blood pressure?⌄

Some studies suggest modest reductions in mild hypertension. Effects are small and hawthorn is not a substitute for proven antihypertensive therapy if you have significant elevation.

References

  • ChEBI: procyanidin B2 — ChEBI Database link
  • Wikidata: Crataegus — Wikidata link

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Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you're pregnant, breastfeeding, on medications, or managing a chronic condition.