Supplement analysis backed by scientific evidence · PT

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Moderate evidenceHeart & metabolic

Hawthorn

Standardised hawthorn extract modestly improves exercise tolerance and symptoms in chronic heart failure as an add-on, but the largest properly powered trial found no survival benefit. It is a symptom aid at best, never a substitute for heart failure medication.

What the science says

  • Improves symptoms and exercise capacity in chronic heart failure Moderate evidence

    A Cochrane review of 14 randomised, double-blind, placebo-controlled trials (855 patients) found hawthorn extract as adjunctive therapy improved maximal workload (weighted mean difference about 5.4 watts), pressure-heart rate product, and shortness of breath and fatigue scores. Trials were mostly short (4-16 weeks), used mildly-to-moderately symptomatic NYHA II-III patients, and predate current guideline therapy.

  • Reduces mortality in heart failure Limited evidence

    The SPICE trial randomised 2,681 patients with NYHA II-III heart failure and reduced ejection fraction to WS 1442 hawthorn extract 900 mg/day or placebo for 24 months on top of standard therapy. It found no significant reduction in the primary composite cardiac endpoint or in all-cause mortality, though a prespecified subgroup with ejection fraction of 25-35% showed a signal for reduced sudden cardiac death that was hypothesis-generating only.

  • Lowers blood pressure Limited evidence

    Small trials in mild hypertension and type 2 diabetes report diastolic reductions of roughly 2-3 mmHg with 1,200 mg/day over 16 weeks. The effect is inconsistent across studies and too small to be clinically useful on its own.

Dosage & safety

Studied doseTrials used 160-1,800 mg/day of standardised leaf-and-flower extract, most commonly the WS 1442 preparation (standardised to 18.75% oligomeric procyanidins) at 900 mg/day in divided doses, or LI 132 (standardised to 2.2% flavonoids). Benefits on exercise capacity took 4-16 weeks. Berry-only preparations and unstandardised teas were not what the trials tested.
SafetyGenerally well tolerated; dizziness, vertigo, nausea, headache and palpitations are the most reported effects and occurred at rates close to placebo in controlled trials. The critical caution is interaction and substitution risk: hawthorn has cardioactive properties and may potentiate digoxin (both increase contractility and slow heart rate), nitrates and other antihypertensives, and beta-blockers. Anyone with heart failure must treat it strictly as an add-on to prescribed therapy — self-medicating with hawthorn while delaying evidence-based treatment is dangerous. Avoid in pregnancy and breastfeeding. Stop before surgery due to cardiovascular effects.

Scientific references

Where to buy

California Gold Nutrition, Magnesium & Hawthorn Extract Complex with Taurine, Coleus Forskohlii Extract, and Hops, 180 Tablets

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