Ranked by evidence
Supplements for muscle cramps: what works and what does not
The evidence for any supplement against ordinary muscle cramps is weak. A 2020 Cochrane review of 11 trials found magnesium unlikely to give clinically meaningful relief for typical night cramps in older adults, and a separate Cochrane review of cramps in pregnancy could not say whether anything works. The only products with moderate-grade evidence that touches cramps are vein products, and only for people with chronic venous insufficiency, so every pick below is situational.
Picks are ranked by the strength of published evidence for this goal in otherwise healthy adults. A persistent symptom needs a clinician's evaluation, and no supplement on this list replaces treatment.
Evidence last reviewed: October 2026
Situational
| Option | Evidence | Best for | The honest note | |
|---|---|---|---|---|
| Vein Support Formulas | Moderate evidence | cramps from chronic venous disease | A meta-analysis of the micronized purified flavonoid fraction (MPFF) found less leg pain, heaviness, swelling and cramps across chronic venous disease. Look for 1000 mg a day of diosmin plus hesperidin, since generic blends rarely match the tested product. | View |
| Troxerutin | Moderate evidence | venous leg symptoms, including cramps | Hydroxyethylrutosides improved pain, cramps, restless legs and swelling versus placebo in chronic venous insufficiency, though many trials were old, small and industry-sponsored. Studied at 1000–2000 mg a day for 4–12 weeks; avoid it in the first trimester of pregnancy. | View |
| Butcher's Broom | Moderate evidence | heavy legs from vein disease | Pooled trials of a Ruscus combination product cut cramps by only 0.26 points on a 0-3 scale, and the tested product had three ingredients, not butcher's broom alone. Use caution with high blood pressure and avoid it with MAO inhibitors. | View |
Popular for this goal — but the evidence says skip
- Magnesium Moderate evidence
A Cochrane review of 11 trials found it unlikely to give clinically meaningful relief for idiopathic cramps in older adults, and the pregnancy trials conflict.
- Leg Cramp Formulas Limited evidence
They rest on magnesium, which probably does not help idiopathic cramps; the one positive trial of a specific magnesium oxide salt has not been replicated, and the added potassium, calcium or B vitamins have no cramp-specific trial support.
- Electrolyte Powder Moderate evidence
The electrolyte-depletion theory of exercise cramp is poorly supported and sodium-loading trials are inconsistent; it helps rehydration after heavy sweating, not cramps as such.
- Magnesium Sulfate (Epsom Salt) Limited evidence
No controlled trial shows an Epsom salt bath reduces cramps or soreness more than a plain warm bath.
- Cramp Bark Limited evidence
Despite the name, there is no modern randomized trial even for menstrual cramps, only cell and animal work.
Our verdict
If your cramps come with heavy, aching or swollen legs from vein disease, a standardized flavonoid such as MPFF or troxerutin is the one evidence-backed option, once a doctor has confirmed the diagnosis. For ordinary night cramps no supplement earns a recommendation, so skip magnesium, Epsom salt and cramp formulas. Cramps that are new, severe or one-sided deserve a medical look.