Hawthorn Berry
Crataegus
Hawthorn (Crataegus spp.; "hawthorn berry," though most standardized clinical extracts such as WS 1442 use leaf-with-flower) is a botanical traditionally used as an adjunct in chronic heart failure and marketed as an "organ-support"/cardiac ancillary. Standardized extracts are rich in oligomeric procyanidins and flavonoids and have shown modest improvements in exercise capacity and heart-failure symptoms in some randomized trials and a Cochrane meta-analysis, but the two most rigorous modern trials (HERB-CHF and the large 2-year SPICE mortality trial) found no benefit on functional endpoints or on the primary cardiac event endpoint. This is a cardioactive substance and should never be used as a substitute for guideline-directed heart-failure therapy; self-treating cardiac symptoms with hawthorn instead of seeking medical care is the primary risk. It is generally well tolerated with mild, transient adverse effects (nausea, dizziness, GI upset), and one trial found more (mostly non-cardiac) adverse events on hawthorn. Anyone with heart disease should only use it under a cardiologist's supervision. This is not an anabolic or performance agent and there is no human data supporting use for "organ support" outside heart failure.
Mechanism of action
Pharmacokinetics
Not well characterized in humans. Individual flavonoid/procyanidin constituents have short plasma half-lives (hours) with low oral bioavailability; no validated single half-life exists for the whole standardized extract.
Clinical dosing is divided (typically twice daily), consistent with a short-acting profile; sustained clinical effects in trials required continued daily dosing over weeks to months rather than reflecting a long single-dose duration.
Oral (film-coated tablets, capsules, tinctures, dried extract of leaf-with-flower or berry).
Polyphenolic constituents undergo extensive gut-microbial and hepatic phase-II metabolism (glucuronidation, sulfation, methylation) with renal and biliary excretion of metabolites. Human PK of the standardized extract is poorly defined; washout data are not well established, so no reliable clearance/washout figure can be stated. Not intended for and not to be used for drug-test evasion.
For monitoring and washout planning, not drug-test evasion.
Physiological & performance effects
- In a Cochrane meta-analysis of 10 RCTs (855 patients, NYHA I-III), hawthorn extract as an adjunct improved maximal workload, exercise tolerance, the pressure-heart-rate product (an index of myocardial oxygen consumption), and symptoms of shortness of breath and fatigue versus placebo.
- In the HERB-CHF RCT (120 patients on contemporary heart-failure therapy), hawthorn produced no improvement in 6-minute walk distance, quality of life, peak oxygen consumption, or neurohormones; only a small LVEF difference favored hawthorn.
- In the large SPICE trial (2681 patients, 24 months), WS 1442 900 mg/day had no significant effect on the primary combined cardiac-event endpoint and no significant effect on cardiac mortality; a post-hoc subgroup with less impaired LVEF (>=25%) suggested reduced sudden cardiac death, a hypothesis-generating finding only.
- Net picture: possible modest symptomatic/exercise benefit in older/adjunctive trials, not confirmed on rigorous functional or hard clinical endpoints in modern trials.
Adverse effects by system
Generally well tolerated; reported cardiac adverse events in trials were infrequent, and in the SPICE trial adverse events were comparable to placebo. Because hawthorn is cardioactive (proposed inotropic/vasodilatory effects), theoretical risks include hypotension and interaction with the effects of cardiac glycosides; palpitations and dizziness have been reported. The greatest cardiovascular danger is indirect: using hawthorn in place of proven heart-failure therapy.
No signal of hepatotoxicity in the reviewed heart-failure RCTs or the WS 1442 benefit-risk review; no adequate dedicated human hepatic-safety data. No established cases of hawthorn-induced liver injury in the retrieved primary literature.
No known effect on the hypothalamic-pituitary-testicular/gonadal axis or other endocrine systems; no human data. Hawthorn is not a hormonal or SERM-type agent.
No adequate human data on fertility, pregnancy, or lactation. Use in pregnancy/breastfeeding is not recommended due to lack of safety data and theoretical uterine/cardiovascular activity.
No established psychiatric adverse effects; dizziness/lightheadedness reported (likely vasomotor rather than psychiatric). No adequate human data on mood/cognition.
No known nephrotoxicity; renal function was not adversely affected in the reviewed trials. No adequate dedicated human renal-safety data beyond heart-failure trial populations.
No established hematologic toxicity. Theoretical additive effects with anticoagulant/antiplatelet drugs are proposed based on flavonoid content but are not confirmed by human interaction studies.
Rare, mild; isolated reports of rash have been described in the broader literature. In the reviewed RCTs skin reactions were not a prominent signal.
HPTA suppression & recovery
Suppression: None expected / not applicable
Hawthorn has no known androgenic, estrogenic, or gonadotropic activity and is not a SERM; no HPTA suppression is expected and no post-cycle or single-SERM recovery framing applies. Any endocrine concerns in an individual should be evaluated and managed by an endocrinologist rather than self-managed.
Monitoring
Cadence: Under the direction of a treating physician; any cardiac-symptom monitoring should follow the clinician's heart-failure follow-up schedule rather than a fixed self-directed interval.
- Worsening shortness of breath, edema, or exercise intolerance (may signal decompensating heart failure requiring urgent medical care, not more supplement)
- Lightheadedness, fainting, or symptomatic low blood pressure
- Palpitations or new/irregular heartbeat
- Chest pain (seek emergency care)
- Allergic reaction (rash, swelling, difficulty breathing)
Contraindications
- Should not replace guideline-directed medical therapy for heart failure or any cardiac condition.
- Known hypersensitivity to Crataegus or Rosaceae-family plants.
- Use only under cardiologist supervision in anyone with diagnosed heart failure, arrhythmia, coronary disease, or hypotension.
- Caution/medical oversight with cardiac glycosides (digoxin/digitoxin), antihypertensives, nitrates, and other cardioactive drugs due to potential additive pharmacodynamic effects (even though a formal digoxin PK interaction study was negative).
- Pregnancy and breastfeeding: avoid due to absence of human safety data.
- Not for use to enhance athletic performance, body composition, or 'organ optimization'—no evidence supports these uses.
Interaction profile
- ContraindicatedWith DNP: Additive cardiovascular strain
Check a specific combination in the interaction checker.
Reducing harm & when to stop
- Do not use hawthorn as a substitute for prescribed heart-failure or cardiac medication; it is at best an adjunct and modern rigorous trials did not confirm benefit.
- If you have any cardiac diagnosis, use it only with your cardiologist's knowledge and supervision.
- Stop and seek prompt medical care for worsening breathlessness, swelling, fainting, chest pain, palpitations, or signs of an allergic reaction.
- Tell every prescriber and pharmacist you are taking it, especially if you use digoxin, blood-pressure medications, nitrates, or anticoagulants.
- Avoid in pregnancy and breastfeeding due to lack of human safety data.
- Do not use it to try to 'optimize' organ function or performance—there is no evidence for such uses and self-medicating cardiac symptoms delays real care.
- Prefer standardized products and disclose use during any bloodwork or clinical monitoring your physician orders.
Citations (6)
Every clinical claim above is tied to a primary source. Overall evidence grade A — graded to the best available evidence for its core claims.
- 01
A Cochrane meta-analysis of 10 RCTs (855 patients, NYHA I-III) found hawthorn extract improved maximal workload, exercise tolerance, pressure-heart-rate product, and symptoms vs placebo, with infrequent, mild, transient adverse events (nausea, dizziness, cardiac/GI complaints) and no adequate mortality/morbidity data.
Meta-analysisDOI 10.1002/14651858.CD005312.pub2 ↗
- 02
In the SPICE trial (2681 patients, NYHA II-III, LVEF<=35%, 24 months), WS 1442 900 mg/day had no significant effect on the primary combined cardiac-event endpoint or cardiac mortality; adverse events were comparable to placebo; a post-hoc LVEF>=25% subgroup suggested reduced sudden cardiac death.
- 03
In the HERB-CHF RCT (120 patients on standard therapy), hawthorn 450 mg twice daily produced no improvement in 6-minute walk distance, quality of life, functional capacity, neurohormones, oxidative stress, or inflammation; a small LVEF difference favored hawthorn; significantly more (mostly non-cardiac) adverse events occurred in the hawthorn group.
- 04
WS 1442 is a standardized leaf-with-flower dry extract (17.3-20.1% oligomeric procyanidins); nonclinical studies show positive inotropic, antiarrhythmic, endothelial-NO-enhancing, antioxidant and ischemia-protective properties; clinical trials and post-marketing surveillance show a favorable safety profile with no observed drug interactions and no specific known adverse reactions.
- 05
Proposed pharmacological mechanisms of standardized Crataegus extract include cAMP-independent positive inotropy, peripheral/coronary vasodilation, protection against ischemia-induced ventricular arrhythmias, antioxidative and anti-inflammatory effects (SPICE rationale/design).
- 06
A randomized crossover study in 8 healthy volunteers found WS 1442 hawthorn 450 mg twice daily for 21 days did not significantly alter any digoxin pharmacokinetic parameter, suggesting the two may be coadministered without a PK interaction at the doses studied.
Last reviewed 2026-07-06 · Verified against PubMed · Educational, not medical advice