Does Magnesium Help With Muscle Cramps?
Last updated: August 2026 · Reviewed by the FactoWiki Editorial Team for clarity and source accuracy
The evidence is weaker than the reputation. Cochrane reviews found magnesium unlikely to help exercise-associated or idiopathic cramps in older adults. There is somewhat better support for pregnancy-related leg cramps. If your magnesium intake is genuinely low, correcting it is reasonable — beyond that, expectations should be modest.
Key takeaways
- Cochrane reviews found no meaningful benefit for idiopathic or exercise cramps.
- Pregnancy leg cramps have somewhat better supporting evidence.
- Cramp causes are often not magnesium — dehydration, fatigue, medication, circulation.
What the reviews concluded
A Cochrane review of magnesium for skeletal muscle cramps found it unlikely to provide meaningful benefit for idiopathic cramps in older adults, and the evidence for exercise-associated cramps was insufficient. This is a case where a strongly held popular belief is not well supported by the trials that tested it.
Where the evidence is better
Pregnancy-related leg cramps have more favourable data, though the trials are still small and mixed. If you are pregnant and getting leg cramps, magnesium is a reasonable thing to raise with your midwife or doctor.
What else causes cramps
Dehydration and electrolyte loss during prolonged sweating, muscle fatigue and overload, statins and diuretics, peripheral arterial disease, and simple nocturnal leg cramps which are common and often unexplained. Persistent or severe cramping, especially with weakness or colour change in the limb, warrants a doctor rather than a supplement.
Key ingredients to understand
The ingredients most relevant to this question, with what the evidence actually supports:
- Magnesium Glycinate — Magnesium glycinate (magnesium bound to glycine) is a gentle, well-absorbed form popular for sleep and relaxation, and easier on the stomach…
- Magnesium — Magnesium is an essential mineral involved in hundreds of body processes, including nerve and muscle function, energy and blood-sugar control.…
- Electrolytes — Electrolytes are the charged minerals that regulate fluid balance, nerve signalling and muscle contraction — principally sodium, potassium,…
- Potassium Citrate — Potassium citrate is a prescription treatment for preventing certain kidney stones and a supplemental potassium source. It is the one…
Frequently asked questions
Is it worth trying anyway?
At 200–400 mg elemental it is cheap and safe, so a four-week trial is reasonable. Just do not expect much on the current evidence.
Which form?
Glycinate or citrate. Oxide is poorly absorbed.
What about pickle juice or salt?
Electrolyte and hydration strategies have more support for exercise-associated cramping than magnesium does.
Related on FactoWiki
- All health answers
- Ingredient evidence guides
- Magnesium Glycinate — ingredient guide
- Magnesium — ingredient guide
- How we review
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