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Can supplemental magnesium alleviate nocturnal leg cramps?

Supplemental magnesium oxide monohydrate was safe and effective in reducing the number and duration of nocturnal leg cramps.


Nocturnal leg cramps (NLC) are linked to various causal factors, including low levels of certain minerals. Although its efficacy is inconclusive, supplemental magnesium is a popular intervention for NLCs. Does magnesium oxide monohydrate reduce the frequency and severity of NLCs?

The study

In this 60-day randomized controlled trial, 216 participants (57 years of age on average) with self-reported NLCs took 226 milligrams of magnesium oxide monohydrate or a placebo. The primary outcome was the number of self-reported NLC episodes. The secondary outcomes were self-reported duration and severity of NLCs, quality of life, and sleep quality (measured using the visual analog scale) reported at baseline, day 30, and day 60.

The results

Overall, 175 participants completed the intervention.

The number of NLCs decreased in both groups compared to baseline but was greater for the magnesium group (−3.4 magnesium vs. −2.6 placebo) at day 60. NLC duration was reduced in both groups at day 30 and more so in the magnesium group by day 60. Sleep quality was also improved in both groups but was improved more in the magnesium group across all timepoints. Quality of life improved in both groups, but subdomains related to physical and emotional health were improved more in the magnesium group.

No adverse events were reported for the magnesium supplement.


A large amount of self-reported data (NLC diagnosis, sleep, pain, quality of life) was used in this study, which is a potential source of bias.

This study was funded by Naveh Pharma Inc., a company that markets magnesium supplements.

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