Magnesium treatment for muscle cramps

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SBU Enquiry Service

Responds to queries received from Swedish healthcare and social service providers, or governmental organisations. Queries have a limited scope and the process is designed to enable a more rapid response, typically within two to three months. Reports are based on systematic reviews, that are identified through structured searches and critically appraised for risk of bias.

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Published: Report no: ut202614 Registration no: SBU 2026/359

Question

What systematic reviews have been published regarding magnesium treatment for muscle cramps?

PICO

  • Population: Adults with recurrent idiopathic muscle cramps1
  • Intervention: Oral or intravenous magnesium supplementation
  • Comparison: Placebo, no treatment or other treatment
  • Outcome: Muscle cramps measured as cramp frequency or intensity

A systematic literature search was performed using the following databases: Medline, Scopus, Embase, and INAHTA database for HTA reports.

Two authors independently assessed the abstracts of all identified studies.

Risk of bias in relevant systematic reviews was assessed using an assessment tool based on AMSTAR.

Identified literature

Two relevant systematic reviews with low to moderate risk of bias were identified [1, 2]. There was an overlap of studies included in the reviews, as well as in their conclusions regarding pregnancy-related leg cramps. Therefore, only the results and conclusions from the review with low risk of bias [1] are presented in Table 1. Three additional systematic reviews were considered to have a high risk of bias; therefore, the results and conclusions are not reported [3-5].

1. Studies are included regardless of the participants’ magnesium level status. Studies on participants with muscle cramps due to a specific condition, such as restless legs syndrome or peripheral neuropathy, have not been included.

Table 1 Systematic review with low risk of bias.
Note. This is a short summary. Please see the review [3], pp. 12–24 for a complete list of results and analyses.
 
CI = Confidence interval; MD = Mean difference; pp. = Pages; RCT = Randomised controlled trial; RR = Risk ratio

a. The review included also one study on cramps associated with liver cirrhosis, which is outside the scope for the present PICO.
b. In two studies, 118 participants crossed over to control.
c. The GRADE approach was used to assess the overall certainty of the evidence.
Included studies Population, Intervention, Control Outcome and Resultsa
Garrison et al, 2020 [1]
Magnesium for skeletal muscle cramps (Review)
Characteristics of included studies
11 RCTs (10 relevant)a 

Parallel design: 8 studies
Cross-over design: 2 studies 

Countries: Argentina, Canada, Iran, Israel, Norway, Sweden, Thailand, UK, USA.		 Population
Older adults with idiopathic muscle cramps (5 studies)Pregnant women with leg cramps (5 studies) 

Intervention
Oral magnesium (9 studies) or intravenous magnesium (1 study) 

Control
Placebo (8 studies)
No treatment, calcium carbonate or vitamin B1 + B6 (1 study)
Calcium or vitamin E (1 study)		 Idiopathic cramps
(5 studies, n=271b) 

Cramp frequency, percentage change from base line at 4 weeks:
(3 studies, n=177)
MD: –9.59 (95% CI, –23.14 to 3.97)
No statistically significant change in cramp frequency, moderate certainty evidencec 

Number of cramps per week, at 4 weeks:
(5 studies, n=236)
MD: –0.18 (95% CI, –0.84 to 0.49)
No statistically significant change in number of cramps, moderate certainty evidencec 

At least 25% reduction in frequency, at 4 weeks:
(3 studies, n=177)
RR: 1.04 (95% CI, 0.84 to 1.29)
No statistically significant results, high certainty evidencec 

Cramp intensity, moderate or worse at 4 weeks:
(2 studies, n=91)
RR: 1.33 (95% CI, 0.81 to 2.21)
No statistically significant change in cramp intensity, moderate certainty evidencec 

Pregnancy-related leg cramps
(5 studies, n=408)
No synthesis due to insufficient or inconsistently reported data.
Authors' conclusion:
”It is unlikely that magnesium supplementation provides clinically meaningful cramp prophylaxis for idiopathic skeletal muscle cramps, largely in older adults, at any of the dosages used. This is supported by evidence of moderate certainty. In contrast, for women suffering pregnancy-associated rest cramps the literature is of lower certainty, conflicting, and unclear.”

References

  1. Garrison SR, Korownyk CS, Kolber MR, Allan GM, Musini VM, Sekhon RK, et al. Magnesium for skeletal muscle cramps. Cochrane Database Syst Rev. 2020;9(9):CD009402. Available from: https://doi.org/10.1002/14651858.CD009402.pub3
  2. Luo L, Zhou K, Zhang J, Xu L, Yin W. Interventions for leg cramps in pregnancy. Cochrane Database Syst Rev. 2020;12(12):CD010655. Available from: https://doi.org/10.1002/14651858.CD010655.pub3
  3. Liu J, Song G, Zhao G, Meng T. Effect of oral magnesium supplementation for relieving leg cramps during pregnancy: A meta-analysis of randomized controlled trials. Taiwan J Obstet Gynecol. 2021;60(4):609–14. Available from: https://doi.org/10.1016/j.tjog.2021.05.006
  4. Patil S, Falkowski A, Venkataiah VS, Bhandi S, Licari FW, Patil AG. The Role of Electrolytes in Muscle Pain Syndromes: A Systematic Review and Meta-Analysis With Implications for Temporomandibular Disorder. Int Dent J. 2026;76(3):109488. Available from: https://doi.org/10.1016/j.identj.2026.109488
  5. Sebo P, Cerutti B, Haller DM. Effect of magnesium therapy on nocturnal leg cramps: a systematic review of randomized controlled trials with meta-analysis using simulations. Fam Pract. 2014;31(1):7–19. Available from: https://doi.org/10.1093/fampra/cmt065

Search strategies

Medline via OvidSP 27 August 26

Title: Magnesium and muscle cramps
/ = Term from the MeSH controlled vocabulary; .sh = Term from the MeSH controlled vocabulary; exp = Term from MeSH including terms found below this term in the MeSH hierarchy; .ti,ab = Title or abstract; .tw = Title or abstract; .kf = Keywords; .kw = Keywords, exact; .bt = Book title. NLM Bookshelf; .pt = Publication type; .ja = Journal abbreviation; .af = All fields; adjn = Adjacent. Proximity operator retrieving adjacent words, adj3 retrieves records with search terms within two terms from each other; * or $ = Truncation; “ “ = Citation Marks; searches for an exact phrase
Search terms Items found
Intervention:
1. Magnesium/ or exp Magnesium Compounds/ or Magnesium Deficiency/ or Potassium Magnesium Aspartate/ 91 564
2. (magnes* or Mg2 or romag).ti,ab,kf,kw,bt. 117 895
Outcome:
3. Muscle Cramp/ 2393
4. (cramp* or musc* spasm* or musc* contraction* or charley horse* or charlie horse* or eamc).ti,ab,kf,kw,bt. 39 356
Study types: systematic reviews and meta-analysis
5. (Systematic Review/ or Meta-Analysis/ or Cochrane Database Syst Rev.ja. or (((systematic or realist or integrative or mixed method* or umbrella) adj4 (review)) or "meta analys*" or metaanalys*).ti,bt,ab.) not (editorial/ or letter/ or case reports/) 636 934
Combined sets:
6. 1 OR 2 160 739
7. 3 OR 4 40 195
Final result
8. 5 AND 6 AND 7 22

Scopus via scopus.com 27 August 26

Title: Magnesium and muscle cramps
TITLE-ABS-KEY = Title, abstract or keywords (including indexed keywords and author keywords); ALL = All fields; W/n = Within. Proximity operator retrieving terms within n words from each other; PRE/n = Precedes by. Proximity operator, the first term in the search must precede the second by n words; LIMIT-TO (X) = Includes only results of specified type, e.g., publication type or time range; DOCTYPE = Publication type; “re” = review; “le” = letter; “ed” = editorial; “ch” = book chapter; “cp” = conference proceedings; * = Truncation; “ “ = Citation Marks; searches for an exact phrase
Search terms Items found
Intervention:
1. TITLE-ABS-KEY (mg2 OR magnes* OR romag) 585 571
Outcome:
2. TITLE-ABS-KEY (cramp* OR "musc* spasm*" OR "musc* contraction*" OR "charley horse*" OR "charlie horse*" OR eamc) 201 814
Study types: systematic reviews and meta-analysis
3. TITLE-ABS-KEY (((systematic OR realist OR integrative OR "mixed method*" or umbrella) W/3 review) OR "meta analy*" OR metaanaly*) AND (EXCLUDE (DOCTYPE, “le”) OR EXCLUDE (DOCTYPE, “ed”) OR EXCLUDE (DOCTYPE, “ch”) OR EXCLUDE (DOCTYPE, “cp”)) 969 203
Combined sets:
4. 1 AND 2 AND 3 105
Final result
5. 1 AND 2 AND 3 105

Embase via Elsevier 27 August 26

Title: Magnesium and muscle cramps
/de = Term from the EMTREE controlled vocabulary; /exp = Term from the EMTREE controlled vocabulary, including all narrower terms in the hierarchy; ti = Title; ab = Abstract; kw = Author keywords; it = Publication type; NEAR/n = Near. Proximity operator retrieving terms within n words from each other; * = Truncation; ‘ ‘ = Citation Marks; searches for an exact phrase
Search terms Items found
Intervention:
1. 'magnesium'/exp 123 004
2. magnes*:ti,ab,kw OR mg2:ti,ab,kw OR romag:ti,ab,kw 113 600
Outcome:
3. 'muscle cramp'/exp 27 007
4. (cramp* OR 'musc* spasm*' OR 'musc* contraction*' OR 'charley horse*' OR 'charlie horse*' OR eamc):ti,ab,kw 59 491
Study types: systematic reviews and meta-analys:ti,ab,kwis
5. ('systematic review'/de OR 'meta analysis'/de OR [cochrane review]/lim OR (((systematic NEAR/4 review) OR 'meta analys*' OR metaanalys*):ti,ab) NOT ('case report'/de OR 'editorial'/it OR 'letter'/it OR 'note'/it)) 924 345
Combined sets:
6. 1 OR 2 179 620
7. 3 OR 4 77 038
Final result
8. 5 AND 6 AND 7 44
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