Hawthorn

Crataegus monogyna / C. laevigata

Family: Rosaceae Part used: Berries (haws), leaves, flowers

Key Compounds

• Vitexin
• Vitexin-2-O-rhamnoside
• Hyperoside
• Rutin
• Isoquercitrin
• Oligomeric procyanidins (OPCs)
• Quercetin
• Chlorogenic acid
• Caffeic acid
• Epicatechin
• Ursolic acid
• Oleanolic acid

Traditional Use

• Cardiovascular support — WS 1442 standardised extract (oligomeric procyanidins) approved as a pharmaceutical for mild cardiac insufficiency (NYHA Class I–II) in Germany; the most clinically researched herbal cardiac treatment in European medicine; approved by German Commission E for declining cardiac performance
• Peripheral vascular disease — evidence for reduction of peripheral arterial resistance and improvement in coronary blood flow through nitric oxide-mediated vasodilation and mild ACE inhibition
• Blood pressure support — multiple trials showing modest reduction in blood pressure in mild hypertension; mechanism through vasodilation and sympatholytic effects
• Traditional Chinese medicine — 山楂 (shanzha, hawthorn berries) used in TCM for thousands of years primarily for digestive applications: fatty food digestion, appetite stimulation, digestive stagnation; different traditional emphasis from European cardiac tradition
• Traditional European medicine — documented use since at least the 10th century CE for heart conditions, diarrhoea, and kidney stones; central to British and German herbalism; deep folk tradition as a sacred tree associated with Beltane, May Day, and boundaries
• Japanese traditional medicine — サンザシ (sanzashi) berries used in Japanese Kampo medicine primarily for digestive applications, following the Chinese tradition; sanzashi jam and preserved berries as traditional food

The May blossom is considered deeply unlucky to bring inside the house.

This is British folk tradition — one of the most persistent plant taboos in the country, documented for centuries. The flowering branches of hawthorn appear in hedgerows throughout May, dense white-pink clusters with a distinctive smell. And they are not supposed to come inside. Possible reasons have been proposed: the smell contains trimethylamine (also found in decomposing bodies), the flowers carry high pollen loads, the associations with pre-Christian Beltane celebrations made the Christian church nervous. None of these is fully satisfying. The taboo persists anyway.

Meanwhile, German cardiologists prescribe a standardised hawthorn extract for mild heart failure. European physicians have clinical trial data supporting its use. The same tree generates both responses simultaneously.

Meet the plant

Shrubs to small trees, 2–10 metres, with thorns, small dark green leaves, and dense clusters of white to pale pink five-petalled flowers in May. The berries — haws — are small, dark red, and mealy in texture, ripening in autumn. The plant grows in hedgerows, woodland edges, and scrubland across Europe and temperate Asia; it is one of the defining features of the traditional British hedgerow landscape.

In China and Japan: Crataegus pinnatifida (山楂, sanzashi) — larger berries, more distinctly tart, the species primarily used in Chinese and Japanese medicine.

The oldest cardiac herb

Documentation of hawthorn for heart conditions appears in European medical writing from the 10th century CE. Medieval physicians described it for palpitations and what they called “weakness of the heart.” Whether their conditions mapped precisely onto what modern cardiologists would diagnose is uncertain; that they were observing cardiovascular effects from the plant is probable.

The 19th century formalized this tradition. Dr. Green of County Clare in Ireland was publishing reports on hawthorn tinctures for heart disease by the 1890s. Continental European herbalists were using it similarly. The herb entered the formal European pharmacopoeia tradition in the early 20th century.

German pharmaceutical research developed the standardised extract WS 1442 — standardised to 18.75% oligomeric procyanidins — and ran a multi-decade programme of clinical trials. The SPICE trial (2,681 patients over ten years) is among the largest clinical trials ever conducted for an herbal product. The German Commission E approved the extract for declining cardiac output and arrhythmias.

The Chinese tradition arrived independently and reached different conclusions. 山楂 (shanzha) in Chinese medicine is primarily used for digestive stagnation — helping heavy, fatty, or difficult-to-digest food. The same plant. The same compounds. Different cultural emphasis.

The chemistry

Oligomeric procyanidins (OPCs) are the primary cardioprotective compounds — the same type found in grape seed extract and pine bark. They activate the nitric oxide pathway in blood vessel endothelium, producing vasodilation and improving coronary blood flow. They also have antioxidant properties protecting cardiovascular tissue.

Vitexin-2-O-rhamnoside is a flavone C-glycoside and the primary standardisation marker in European pharmaceutical preparations. It contributes to the chronotropic and inotropic effects (normalising heart rate and contraction strength).

Hyperoside and rutin are flavonol glycosides contributing antioxidant activity.

Organic acids (malic, citric, tartaric) in the berries contribute to the tart flavour and the digestive-stimulating effects that the Chinese tradition emphasizes.

What people actually do with it

Standardised extract (cardiac applications): WS 1442 or equivalent standardised to OPCs or vitexin-2-O-rhamnoside. 160–900 mg daily in divided doses. Allow 4–8 weeks for effects to develop. This is the form with the clinical evidence base.

Berry tea: 1–2 teaspoons of dried haws (berries) simmered 15–20 minutes. Mildly tart, pleasant flavour. Less standardised but traditional. The Chinese tradition uses this form most commonly for digestive applications.

Tincture: 1–2 mL, three times daily. The full compound matrix including OPCs and flavonoids.

Jam and food: Hawthorn berries are made into jam, jelly, and traditional European fruit preserves. High pectin content makes them good for preserving. The Chinese form (shanzha) is eaten as preserved fruit and in traditional sweets. Both are food uses, not supplement doses.

Important: Do not use as a replacement for prescribed cardiac medications. The clinical evidence is for mild insufficiency as adjunctive or stand-alone treatment in milder cases.

Could you grow this yourself?

Yes, if you have space. Hawthorn is one of the most robust and long-lived shrubs in temperate climates.

Crataegus monogyna and C. laevigata grow across all of Japan’s temperate zones. They tolerate poor soil, exposure, and cold. They are used as hedgerow plants. C. pinnatifida (sanzashi) is cultivated in parts of Japan for the larger berries.

The thorns are serious — handle with care during harvest. Berries ripen in autumn; harvest when deep red and slightly soft. Leaves and flowers should be harvested when the flowers are just opening in May.

Hawthorn (サンザシ) in Japan

Japan’s traditional relationship with hawthorn is primarily through the Chinese herbal tradition.

サンザシ (sanzashi, Crataegus pinnatifida) appears in Japanese traditional medicine following the Chinese emphasis on digestive applications. It is listed in the Japanese Pharmacopoeia as an approved crude drug. Kampo formulas that include it use it primarily for food stagnation and digestive insufficiency.

Sanzashi berries are also a traditional food in Japan — dried preserved berries, sanzashi jam, and sanzashi drinks are regional specialties in some areas. The preserved berry has a sweet-tart flavour and is eaten as a snack.

The European cardiac tradition — pharmaceutical hawthorn extract for mild heart failure — reaches Japan primarily through the supplement market. WS 1442 and equivalent standardised extracts are available at natural supplement retailers. The distinction between the digestive-focused Japanese traditional use and the cardiac-focused European pharmaceutical application is worth noting: they are using related compounds with different applications.

Things you’re probably wondering

What does the clinical research show? The SPICE trial (2,681 patients, 10 years): modest benefit in a specific heart failure subpopulation. Multiple smaller trials: consistent improvement in exercise tolerance and cardiac efficiency for mild heart failure. German Commission E approved for declining cardiac output.

Why is May blossom unlucky to bring inside? British folk tradition, possibly connected to trimethylamine in the scent (associated with decomposition), high pollen content, or historical associations with pre-Christian festivals. The taboo is well documented; the origin is not definitively established.

What is the difference between Chinese and European traditions? European tradition: cardiovascular (cardiac tonic, blood pressure, heart failure). Chinese/Japanese tradition: digestive (food stagnation, fatty food digestion). Both derive from the same plant; different compounds and preparations are emphasised.

Can it replace heart medications? No. Evidence is for mild insufficiency, used alongside or instead of medications only for milder cases. Never discontinue cardiac medications to take hawthorn.

Botanical details

The full compound list

See Also

• Garlic — cardiovascular herb with complementary mechanisms (platelet aggregation, lipids)
• Licorice Root — another traditional cardiac herb in kampo; different mechanism (cortisol extension)
• Eleuthero — adaptogen with cardiovascular stress-protection effects

References

• Pittler, M.H. et al. (2008). Hawthorn extract for treating chronic heart failure. Cochrane Database of Systematic Reviews, 1, CD005312.
• Holubarsch, C.J.F. et al. (2008). The efficacy and safety of Crataegus extract WS 1442 in patients with heart failure (SPICE trial). European Journal of Heart Failure, 10(12), 1255–1263.
• European Medicines Agency. (2016). Assessment report on Crataegus spp. Committee on Herbal Medicinal Products (HMPC).
• Chang, Q. et al. (2002). Hawthorn. Journal of Clinical Pharmacology, 42(6), 605–612.