Condition

Muscle Cramps

Muscle cramps are sudden, painful contractions of a muscle, most often in the calves, feet, or back, and they can follow dehydration, electrolyte shifts, tired muscles, or certain medications. People most often look at magnesium and electrolytes such as sodium and potassium, but little research on them has been reviewed here so far. One trial of pickle juice found it inhibited cramps brought on by electrical stimulation, so the evidence there is limited.

Sources: PMID 20386132

Supplements studied: 2
Graded outcomes: 0
Trials: 6
People studied: 1,459

Evidence by supplement

Strong
Moderate
Limited
Very limited

2 supplements

Magnesium

Magnesium: outcomes studied for Muscle Cramps
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Cramps	Improves (the measure goes down)		8 studies	177 people
Studies that measured cramps Magnesium for skeletal muscle crampsCochrane Database Syst Rev · PMID 32956536 Does oral magnesium substitution relieve pregnancy-induced leg crampsEur J Obstet Gynecol Reprod Biol · PMID 18768245 The effect of magnesium infusion on rest cramps: randomized controlled trial.J Gerontol A Biol Sci Med Sci · PMID 21289017 and 5 more on the Magnesium page

L-Carnitine

L-Carnitine: outcomes studied for Muscle Cramps
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Cramps	Improves (the measure goes down)		1 study	42 people
Studies that measured cramps L-carnitine Reduces Muscle Cramps in Patients With CirrhosisClin Gastroenterol Hepatol · PMID 25496816

What the published studies found

1 automated reading

Automated reading of the published studies (Decosa evidence engine), for outcomes Winnowleaf has not graded yet. It is not a Winnowleaf grade and does not change one. How it is read

Magnesium: muscle cramps
A Cochrane review (2020, 11 studies, 735 people) found little or no difference in muscle cramps. That review studied people with skeletal muscle cramps. 7 of the 10 studies read agree; 1 found mixed results, 1 found an improvement, 1 found no clear answer. The evidence is moderate.
Side effects: 2 of the 5 studies that reported on them found more with Magnesium (gastrointestinal side effects, gastrointestinal adverse events).
10 studies counted of 11 read: 5 reviews and 5 trials (331 people in the trials).
1. Meta-analysis, 2020; 11 studies, 735 people; people with skeletal muscle cramps: no clear difference (the review the verdict rests on). differences in measures of cramp frequency when comparing magnesium to placebo were small Magnesium for skeletal muscle crampsPubMed 32956536
2. Meta-analysis, 2026; 13 studies, 760 people; adults with muscle cramps or myalgia: mixed results. magnesium significantly reduced cramp frequency compared with placebo The Role of Electrolytes in Muscle Pain Syndromes: A Systematic Review and Meta-Analysis With Implications for Temporomandibular DisorderPubMed 41812583
3. Meta-analysis, 2021; 4 studies, 332 people; pregnant women: no clear difference. frequency of leg cramps after treatment was not decreased Effect of oral magnesium supplementation for relieving leg cramps during pregnancy: A meta-analysis of randomized controlled trialsPubMed 34247796
4. Systematic review, 2020; 8 studies, 576 people; women with leg cramps in pregnancy: unclear: evidence too weak to tell. results indicated that women may be more likely to report never having any leg cramps Interventions for leg cramps in pregnancyPubMed 33275278
5. Meta-analysis, 2014; 7 studies, 361 people; adults with nocturnal leg cramps: no clear difference. difference in the median number of leg cramps per week Effect of magnesium therapy on nocturnal leg cramps: a systematic review of randomized controlled trials with meta-analysis using simulationsPubMed 24280947
6. Randomised trial, 2020; 132 people; pregnant women with leg cramps in first trimester: no clear difference. no difference between the two groups was found Oral magnesium supplementation for leg cramps in pregnancy-An observational controlled trialPubMed 31923242
7. Randomised trial, 2011; 46 people; community-dwelling older adult rest cramp sufferers: no clear difference. magnesium versus placebo arms, was -2.4 versus -1.7 The effect of magnesium infusion on rest cramps: randomized controlled trialPubMed 21289017
8. Randomised trial, 2008; 38 people; pregnant women with leg cramps: no clear difference. no significant differences between the two groups Does oral magnesium substitution relieve pregnancy-induced leg cramps?PubMed 18768245
9. Crossover trial, 1999; 42 people; ambulatory patients with frequent nocturnal leg cramps: no clear difference. no significant differences between magnesium and placebo Magnesium for the treatment of nocturnal leg cramps: a crossover randomized trialPubMed 10907623
10. Randomised trial, 1995; 73 people; women with pregnancy-related leg cramps: improves. decreased leg cramp distress (p < 0.05 The effect of oral magnesium substitution on pregnancy-induced leg crampsPubMed 7631676
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.

The Muscle Cramps Supportive Care protocol

2 primary supplements · 6 supporting supplements

Magnesium300–500 mg daily (citrate, glycinate, or malate forms preferred)
Electrolytes (Sodium, Potassium)Electrolyte beverages during/after exercise or as needed; ensure adequate dietary intake

See the full protocol

Shop the evidence-backed picks

Fullscript collectionMuscle, performance and healthy ageing: evidence-graded picksOpen on Fullscript

The collection holds the supplements we grade A or B for its theme, in products from the Fullscript catalog. It opens in our Fullscript store. You can look through it without signing in; Fullscript asks for a free account to order.

We earn from purchases made in our Fullscript store, and links to Fullscript, iHerb or Thorne carry our referral, so we may earn a commission at no extra cost to you. Grades come from the research and never change based on what we earn. Full disclosure

Studies cited

9 studies from PubMed

MAGraine: Magnesium compared to conventional therapy for treatment of migraines.Am J Emerg Med · PMID 33041146
Effect of oral magnesium supplementation for relieving leg cramps during pregnancy: A meta-analysis of randomized controlled trials.Taiwan J Obstet Gynecol · PMID 34247796
A randomized, double-blind, placebo-controlled, multicenter study assessing the efficacy of magnesium oxide monohydrate in the treatment of nocturnal leg crampsNutr J · PMID 34719399
Magnesium for the treatment of nocturnal leg cramps: a crossover randomized trial.J Fam Pract · PMID 10907623
Randomised, cross-over, placebo controlled trial of magnesium citrate in the treatment of chronic persistent leg cramps.Med Sci Monit · PMID 12011773
The effect of magnesium infusion on rest cramps: randomized controlled trial.J Gerontol A Biol Sci Med Sci · PMID 21289017
Does oral magnesium substitution relieve pregnancy-induced leg crampsEur J Obstet Gynecol Reprod Biol · PMID 18768245
Magnesium for skeletal muscle crampsCochrane Database Syst Rev · PMID 32956536
L-carnitine Reduces Muscle Cramps in Patients With CirrhosisClin Gastroenterol Hepatol · PMID 25496816