European thorny shrub with regulatory approval and clinical trial evidence for mild heart failure (NYHA II), though benefit when added to contemporary standard therapy remains unclear. Also reduces blood pressure in mild hypertension with at least 12 weeks of treatment.
Traditions: European herbal medicine, German phytomedicine, Traditional Chinese Medicine
Approved for mild congestive heart failure and 'nervous heart complaints' — specifically for decreasing cardiac output as described in NYHA functional stage II. Approved preparation: leaf with flower combined. Limited scientific support noted for berry, flower, or leaves used separately.
Recognized for cardiovascular support. Traditional preparations documented as teas, tinctures, and decoctions from leaves, flowers, and berries.
Listed hawthorn berries as a cardiovascular tonic. Long regarded as the standard reference text for professional British herbalists.
Older meta-analyses and RCTs show significant functional improvements in NYHA II-III heart failure; however, the 2009 HERB CHF trial found no benefit when hawthorn was added to contemporary standard therapy. Blood pressure reduction in mild hypertension is supported but requires at least 12 weeks.
8 clinical trials, 632 patients. Maximal workload increased by 7 Watts on average. Pressure-heart rate product decreased by 20 points. Dyspnea and fatigue improved significantly over placebo.
2,681 patients, WS 1442 900 mg/day for 24 months. Primary endpoint (time to first cardiac event) not significantly different. Subgroup with ejection fraction ≥25% showed 39.7% reduction in sudden cardiac death.
120 patients with NYHA II-III on standard therapy. No significant improvement in 6-minute walk distance, quality of life, or functional capacity. Modest ejection fraction improvement favored hawthorn.
6 clinical trials, 428 patients. Clinically significant blood pressure reduction in mild hypertension.
Taste: Mildly astringent
WS 1442 is extracted from leaf with flower in 45% ethanol, standardized to 17.3-20.1% oligomeric procyanidins. At 900 mg/day this provides 84.3 mg of oligomeric procyanidins. Used in SPICE (2,681 patients, 24 months) and HERB CHF (120 patients, 6 months). Minimum 8 weeks for heart failure effects; 12 weeks for blood pressure effects.
Taste: Mildly sweet, slightly floral, lightly astringent
Traditional preparation. Steep in boiling water for 10-20 minutes, covered. No clinical trial data applies to tea preparations — concentrations are substantially lower than standardized extracts.
Taste: Astringent, mildly sweet
Traditional preparation from leaf with flower or berries. Documented in European herbalist tradition. No clinical trial data validates tinctures for cardiovascular endpoints.
Hawthorn (Crataegus spp.) occupies an unusual position in the herbal evidence landscape. It carries formal regulatory approvals — the German Commission E approved it in 1978, the European Medicines Agency has issued an assessment report, and the World Health Organization included it in its medicinal plant monographs — alongside a clinical trial record that is positive in older studies and more complicated in recent ones.
The primary evidence is for chronic heart failure classified as NYHA class II or III — mild to moderate impairment in which the heart pumps less blood than normal and physical activity causes noticeable fatigue or breathlessness. A meta-analysis of 8 clinical trials with 632 patients found hawthorn extract produced meaningful exercise improvements: maximum workload increased by an average of 7 Watts (95% CI: 3-11 Watts; n=310), and the pressure-heart rate product (a measure of how hard the heart works under load) decreased by an average of 20 points (95% CI: -32 to -8; n=264) [1]. Breathlessness and fatigue improved significantly compared to placebo [1].
The largest single trial — the SPICE trial — enrolled 2,681 patients (1,338 active, 1,343 placebo) with NYHA II-III heart failure and low heart pump function (ejection fraction of 35% or below) [2]. Patients received WS 1442 extract at 900 mg/day — providing 84.3 mg of oligomeric procyanidins (the primary active compounds) — or placebo for 24 months [2]. The primary endpoint, time to first cardiac event, was not significantly different between groups: 27.9% event rate in the hawthorn group versus 28.9% in placebo (hazard ratio 0.95, 95% CI: 0.82-1.10; p=0.476) [2]. One subgroup finding stood out: in patients whose hearts were pumping at least 25% of normal capacity, hawthorn reduced sudden cardiac death by 39.7% compared to placebo (hazard ratio 0.59; p=0.025) [2]. This subgroup result has not been confirmed in a dedicated trial.
The critical negative result came from the HERB CHF trial in 2009: 120 patients with NYHA II-III heart failure, all on contemporary standard therapy including ACE inhibitors, beta-blockers, and diuretics, received 450 mg hawthorn extract twice daily or placebo for 6 months [3]. There was no significant improvement in 6-minute walk distance (the primary endpoint, P=0.61), quality of life, functional capacity, neurohormones, oxidative stress, or inflammation [3]. A modest improvement in left ventricular ejection fraction favored hawthorn (P=0.04) [3]. More adverse events occurred in the hawthorn group (P=0.02), though most were non-cardiac [3].
Two smaller positive trials predate the modern therapeutic context. Degenring 2003 randomized 143 patients (69 active, 74 placebo; 72 men, 71 women; mean age 64.8 years) with NYHA II heart failure to fresh hawthorn berry extract (Crataegisan, 3 times 30 drops daily) for 8 weeks, finding an 8.3-watt advantage in bicycle exercise tolerance over placebo (p=0.045) [4]. Breathlessness and fatigue occurred at significantly higher workloads in the active group [4]. Leuchtgens 1993 found statistically significant improvement in the pressure-heart rate product in 30 NYHA II patients given WS 1442 for 8 weeks compared to placebo, with no adverse events in either group [5].
A benefit-risk assessment of WS 1442 covering more than 1,300 patients in clinical trials concluded the benefit-risk balance is positive, noting increased functional capacity, improved quality of life, and a very favorable safety profile with no drug interactions observed and no specific adverse reactions identified [6].
Blood pressure: A 2025 meta-analysis of 6 clinical trials with 428 patients found clinically significant blood pressure reduction in mild hypertension [7]. A systematic review found this effect requires a minimum of 12 weeks of treatment, and that the few available studies were too different from one another to pool into a definitive meta-analysis [8].
The evidence picture in plain terms: hawthorn shows functional improvements in older heart failure trials and holds regulatory approval from multiple authorities, but the most rigorous and recent test — against modern standard heart failure therapy — found no significant benefit [3]. The most likely interpretation is that hawthorn’s contribution is harder to measure against a modern drug regimen (ACE inhibitors, beta-blockers, diuretics) than it was against the older, less effective standard care in which the earlier trials were run.
European herbal medicine documented hawthorn as a cardiovascular tonic well before modern clinical trials, and official recognition followed systematically from the late 20th century onward.
The German Commission E approved hawthorn leaf with flower in 1978 for mild congestive heart failure and “nervous heart complaints” — specifically defined as the functional impairment of NYHA stage II [13]. The Commission E noted limited scientific support for berries, flowers, or leaves used separately, and recommended the combined leaf-with-flower preparation [13]. This approval shaped the form of subsequent clinical research, with most trials using the leaf-with-flower standardized extracts WS 1442 and LI 132.
The World Health Organization included hawthorn in its Monographs on Selected Medicinal Plants (Volume 1, 1999), documenting use across multiple traditions for cardiovascular support through teas, tinctures, and decoctions [15]. The British Herbal Pharmacopoeia (1983) cited hawthorn berries as the primary preparation, regarded as the standard reference text among British professional herbalists for decades [16].
The European Medicines Agency (EMA) published a formal assessment report on Crataegus spp., folium cum flore (leaf with flower), establishing therapeutic indications, dosing requirements, and safety standards [14]. The American Herbal Pharmacopoeia maintains dedicated monographs for both hawthorn leaf and flower and hawthorn berry, describing it as “the most widely used botanical for supporting the cardiovascular system.”
Traditional Chinese Medicine uses a related species — Crataegus pinnatifida (Chinese hawthorn) — primarily for digestive support and food stagnation rather than cardiac indications, in contrast to the European tradition’s cardiovascular focus [10]. A comprehensive phytochemical review of the Crataegus genus covering 1952-2023 identified 337 distinct chemical compounds across multiple species and documented pharmacological activities including cardiovascular and cerebrovascular effects, anti-inflammatory properties, hepatoprotective effects, and antimicrobial activity [10].
The clinical evidence is entirely for standardized extracts. No trials have tested teas, tinctures, or whole plant preparations for cardiovascular endpoints. Traditional preparations are documented and used, but clinical evidence does not extend to them.
WS 1442 is the most thoroughly characterized preparation: extracted from hawthorn leaf with flower (drug-to-extract ratio 4-6.6:1) in 45% ethanol, standardized to 17.3-20.1% oligomeric procyanidins. The standard dose is 900 mg/day, providing 84.3 mg oligomeric procyanidins [2,6]. The SPICE trial used 900 mg/day (450 mg twice daily) for 24 months [2]; the HERB CHF trial used the same dose for 6 months [3].
LI 132 is a second studied extract, standardized to 2.2% flavonoids in methanol, used in a range of 160-1800 mg/day across trials [9]. It has a slightly less clean safety record than WS 1442 — eight severe adverse events were reported with LI 132 in the large safety review [9].
Fresh berry extract (Crataegisan, 3 times 30 drops daily for 8 weeks) showed an 8.3-watt exercise improvement in 143 NYHA II patients, though it is not as well characterized as WS 1442 [4].
Hawthorn is a slow-acting herb in all its forms. Clinical trials consistently show effects requiring at least 4-8 weeks of consistent daily use to appear. Blood pressure effects require at least 12 weeks [8].
1-2 teaspoons dried hawthorn leaf and flower per cup of boiling water, steeped 10-20 minutes, covered, 2-3 cups daily. Documented in the WHO and British Herbal Pharmacopoeia monographs as a traditional cardiovascular preparation. Concentrations are substantially lower than standardized extracts; no clinical endpoint data applies.
2-5 mL, 2-3 times daily, in 1:5 (herb to liquid) in 25-45% ethanol. Used across European herbalist tradition from leaf with flower or berries. No clinical trial data validates tinctures for cardiovascular outcomes.
Baseline before starting:
During a trial (minimum 8 weeks for heart failure effects, 12 weeks for blood pressure):
The improvements found in clinical trials were measured by bicycle exercise testing — functional changes in how much work the heart could do before symptoms emerged. The 7-watt average improvement from meta-analysis [1] and 8.3-watt advantage in the Degenring 2003 trial [4] represent gradual functional shifts rather than dramatic symptom reversals.
Where the evidence applies:
Where evidence is weaker or absent:
Pregnancy and breastfeeding: Precautionarily contraindicated during pregnancy despite animal studies at 56 times the human dose showing no adverse effects on embryonic development [12]. No human pharmacokinetic or safety data. Avoid during breastfeeding [12].
All clinical evidence for hawthorn comes from standardized pharmaceutical extracts. The difference between WS 1442 and LI 132 matters for safety and product selection.
WS 1442 is the most extensively studied and has the cleanest safety record: standardized to 17.3-20.1% oligomeric procyanidins, extracted from leaf with flower in 45% ethanol. More than 1,300 patients studied in trials led to the conclusion that no drug interactions have been observed and no specific adverse reactions have been identified [6]. The 2,681-patient SPICE trial over 24 months found adverse events comparable between hawthorn and placebo [2].
LI 132 is also studied but has a slightly more variable safety record: 8 severe adverse events were reported with LI 132 across the 5,577-patient safety review, though most events in the entire dataset were mild to moderate [9].
The European Pharmacopoeia requires oligomeric procyanidin standardization for hawthorn pharmaceutical products. When selecting a WS 1442-type product, look for an explicit oligomeric procyanidin percentage (target range: 17-20%) rather than a vague “hawthorn extract” label.
Of the 337 chemical compounds identified in the Crataegus genus, epicatechin is the primary flavonoid that reaches the bloodstream after oral dosing — animal studies found it absorbed at 10.9% bioavailability from extract and 34.2% from pure compound, while other flavonoids including chlorogenic acid, hyperoside, and isoquercitrin showed very limited absorption [11]. The relationship between which compounds are absorbed and which are responsible for clinical cardiovascular effects remains an active research question [11].
Tea and tincture preparations are not equivalent to standardized extracts and carry no clinical evidence for cardiovascular or blood pressure outcomes. They represent traditional preparations with a long documented use history but a different intervention than what clinical trials have tested.
Hawthorn is a well-documented cardiovascular herb with more institutional backing than most — regulatory approval from the German Commission E, inclusion in WHO monographs, and assessment by the European Medicines Agency. Older clinical trials show meaningful functional improvements in mild heart failure. The herb is well-tolerated across more than 7,000 patient exposures [9].
The complication: the most rigorous modern trial, against contemporary standard heart failure medications, found no significant benefit [3]. What that means in practice depends on context — the older positive trials were against less effective background therapy, and hawthorn’s incremental contribution appears harder to detect alongside modern ACE inhibitors and beta-blockers.
For mild hypertension, the evidence base is smaller but positive — with the important caveat that effects require at least 12 weeks [7,8].
What hawthorn is not: a fast-acting cardiac intervention, a replacement for conventional treatment, or an option for severe or acute heart conditions.
[1] Pittler MH, Schmidt K, Ernst E. Hawthorn extract for treating chronic heart failure: meta-analysis of randomized trials. Am J Med. 2003;114(8):665-674. PMID: 12798455
[2] Holubarsch CJF, Colucci WS, Meinertz T, Gaus W, Tendera M. The efficacy and safety of Crataegus extract WS 1442 in patients with heart failure: the SPICE trial. Eur J Heart Fail. 2008;10(12):1255-1263. PMID: 19019730
[3] Zick SM, Vautaw BM, Gillespie B, Aaronson KD. Hawthorn Extract Randomized Blinded Chronic Heart Failure (HERB CHF) trial. Eur J Heart Fail. 2009;11(10):990-999. PMID: 19789403
[4] Degenring FH, Suter A, Weber M, Saller R. A randomised double blind placebo controlled clinical trial of fresh Crataegus berries (Crataegisan) in NYHA II heart failure. Phytomedicine. 2003;10(5):363-369. PMID: 12833999
[5] Leuchtgens H. Crataegus Special Extract WS 1442 in NYHA II heart failure: placebo controlled randomized double-blind study. Fortschr Med. 1993;111(20-21):352-354. PMID: 8375791
[6] Holubarsch CJF, Colucci WS, Eha J. Benefit-risk assessment of Crataegus extract WS 1442: evidence-based review. Am J Cardiovasc Drugs. 2018;18(1):25-36. PMID: 29080984
[7] Szikora Z, Mátyus RO, Szabó BV, Csupor D, Tóth B. Hawthorn (Crataegus spp.) clinically significantly reduces blood pressure in hypertension: meta-analysis of 6 RCTs, 428 patients. Pharmaceuticals. 2025;18(7):1027.
[8] Cloud AME, Vilcins D, McEwen BJ. The effect of hawthorn (Crataegus spp.) on blood pressure: a systematic review. Adv Integr Med. 2020;7(3):167-175.
[9] Daniele C, Mazzanti G, Pittler MH, Ernst E. Adverse-event profile of Crataegus spp.: systematic review. Drug Saf. 2006;29(6):523-535. PMID: 16752934
[10] Cui M, et al. Traditional uses, phytochemistry, pharmacology, and safety concerns of hawthorn (Crataegus genus): comprehensive review. J Ethnopharmacol. 2024;319(Pt 2):117229. PMID: 37788786
[11] Chang Q, Zuo Z, Ho WKK, Chow MSS. Comparison of the pharmacokinetics of hawthorn phenolics in extract versus individual pure compound. J Clin Pharmacol. 2005;45(1):106-112. PMID: 15601812
[12] Yao M, Ritchie HE, Brown-Woodman PD. A reproductive screening test of hawthorn. J Ethnopharmacol. 2008;118(1):127-132. PMID: 18485639
[13] German Commission E. Crataegus leaf with flower (Crataegi folium cum flore) monograph. Approved for NYHA II mild congestive heart failure, 1978. In: Blumenthal M, Goldberg A, Brinckmann J (eds.) Expanded Commission E Monographs. Newton, MA: Integrative Medicine Communications; 2000.
[14] European Medicines Agency. Assessment report on Crataegus spp., folium cum flore. https://www.ema.europa.eu/en/documents/herbal-report/final-assessment-report-crataegus-spp-folium-cum-flore_en.pdf
[15] World Health Organization. WHO Monographs on Selected Medicinal Plants, Volume 1. Geneva: World Health Organization; 1999.
[16] British Herbal Pharmacopoeia. Hawthorn. London: British Herbal Medicine Association; 1983.
Full bibliography: bibliographies/hawthorn.yaml
Duration: Slow-acting — initial effects require at least 4-8 weeks of consistent daily use. Blood pressure effects require a minimum of 12 weeks. Clinical trials ran 8 weeks to 24 months.
What to notice:
Clinical trials divided 900 mg/day into two doses (450 mg morning and evening). Effects are gradual — hawthorn does not produce rapid cardiovascular changes. The 7-watt exercise improvement found in meta-analysis represents a functional shift rather than dramatic symptom reversal.
Generally considered: caution
Contraindications:
Pregnancy/Nursing: Contraindicated in pregnancy as a precaution, despite no reproductive toxicity in animal studies at 56 times the human dose. No human safety data. Avoid during breastfeeding. [12]
Over 7,000 patients studied in clinical trials up to 24 months. Adverse events are infrequent and mostly mild — 166 total events across 5,577 patients in 24 trials. Most common: GI symptoms (24 cases), dizziness (15), palpitations (11), headache (9), migraine (8). Eight severe adverse events were reported with LI 132 extract. WS 1442 specifically: no drug interactions and no specific adverse reactions identified in more than 1,300 patients. [6,9]