Crataegus monogyna, Crataegus laevigata · herb
Evidence tier: weak
Strengthens the heart muscle, dilates coronary and peripheral blood vessels, and reduces mild hypertension, one of the most evidence backed herbs for cardiovascular support
Oligomeric proanthocyanidins and flavonoids such as vitexin and hyperoside are proposed to dilate coronary and peripheral vessels, mildly increase myocardial contractility and protect endothelium from oxidative stress. This is the standard laboratory account and it is plausible; it is not proven to be what is happening in people, and the largest human trial designed to detect a downstream mortality effect of exactly this mechanism found none. The mechanism is also the source of the drug interaction risk rather than a selling point.
Weak for anything PlantRx is permitted to claim, and this ingredient is a textbook disease population trap. There IS a positive Cochrane review: Pittler and Guo (2008, CD005312, 14 trials, about 900 people) concluded that hawthorn extract shows significant benefit over placebo as an ADJUNCTIVE treatment for patients with CHRONIC HEART FAILURE, improving exercise tolerance and symptoms, with infrequent and mild adverse events. That evidence is real, and it is unusable for a consumer supplement. Chronic heart failure is a diagnosed cardiac disease managed with prescription therapy; evidence generated in that population cannot be carried across to a general wellness claim, and to do so would be to recommend a botanical to people who should be under cardiology care. It gets worse for the claim, not better: the largest trial ever run on hawthorn, SPICE (Holubarsch 2008, 2,681 patients with NYHA class II to III heart failure on standard therapy, WS 1442 at 900 mg daily for 24 months), MISSED ITS PRIMARY ENDPOINT. Hawthorn did not significantly reduce cardiac mortality; time to first cardiovascular event, deaths from heart failure and heart failure hospitalisations were the same as placebo. A benefit survived only in a prespecified subgroup with left ventricular ejection fraction of 25 to 35 percent, which is a subgroup finding in a failed trial, not a result. And the regulator will not carry the claim either: the current EU herbal monograph for Crataegus folium cum flore is TRADITIONAL USE only, for temporary heart complaints related to nervousness such as palpitations, for mild symptoms of mental stress and to aid sleep, in adults only, and after serious conditions have been excluded by a doctor. There is no NYHA indication and no heart failure indication in the monograph. Strip out the disease population and what remains is a traditional use nervine with no trial support. That is weak. Safety is the one clean part of the file: NIH LiverTox gives hawthorn likelihood score E, unlikely to cause liver injury, noting it has not been implicated in drug induced liver injury despite widespread use.
160 to 900 mg of standardised extract daily is the range circulating in the supplement market; WS 1442 was studied at 300 mg three times daily. Any of these doses sits in territory where hawthorn interacts with cardiac medication, so a dose figure alone is not the useful output here: nobody on a heart or blood pressure drug should be taking hawthorn without medical supervision.
Take 160 to 900mg of standardised extract daily. Effects build over 4 to 8 weeks of consistent use. Well tolerated long term; often used in combination with other cardiovascular herbs.
DRUG INTERACTION WARNING: Significant interactions with cardiac medications. Hawthorn potentiates digoxin (increased inotropic effect, toxicity risk), additive hypotension with beta-blockers, nitrates, and antihypertensives. Additive vasodilation with PDE5 inhibitors (sildenafil, tadalafil). Do not use without medical supervision if on any heart or blood pressure medication. Otherwise well tolerated, mild GI upset in some. Not for acute cardiac events.
Pregnancy: avoid
Breastfeeding: caution
Active compounds: oligomeric proanthocyanidins, vitexin, hyperoside, quercetin, chlorogenic acid
Remedies using Hawthorn · Browse by body system · Check it against what you take
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.