Magnesium
An essential mineral found in seeds, nuts, beans and leafy greens. The supplement evidence depends on the question: correcting an inadequate intake, improving sleep and preventing migraine are different uses.
What magnesium does, and what supplements can offer
Magnesium appears in sleep aids, sports supplements and headache remedies. The evidence differs for each use. Start with the result you are interested in, then look at what studies have measured and how confidently they support that claim.
Every cell needs magnesium. It helps nerves and muscles work and supports the processes that supply energy. These essential roles alone do not justify taking extra magnesium as a precaution. 1
Health effects, one question at a time
These summaries describe particular outcomes and populations. Open a question to see the evidence behind it.
Some positive findings; results across trials are inconsistent.
Low–very low certaintyLimited evidence for reducing frequency in diagnosed migraine.
Possible benefitNight-time muscle crampsOlder adults are unlikely to gain a meaningful benefit.
Moderate certainty
How much magnesium do adults need?
EFSA’s adequate intake is a reference for total daily intake, including food. It is not the amount to add as a supplement. 2
Total intake from all sources
Total intake from all sources
300 mg for women and 350 mg for men are daily intake references that include food and drinks. They are not amounts to take as a supplement.
250 mg/day is a separate European upper limit for specified magnesium compounds in supplements and added sources. Naturally occurring magnesium in food does not count towards this limit. 7
Magnesium in everyday foods
These reference portions make the amounts easier to compare. Preparation and portion size affect the result.
| Food | Reference serving | Magnesium |
|---|---|---|
| Roasted pumpkin seeds | 1 oz · approximately 28 g | 156 mg |
| Almonds | 1 oz · approximately 28 g | 80 mg |
| Boiled spinach | ½ cup | 78 mg |
| Cooked black beans | ½ cup | 60 mg |
When a supplement deserves a closer look
Diarrhoea, nausea and abdominal cramps are common reasons to reconsider an amount or product. Kidney disease can increase the risk of magnesium toxicity. 6
Medicines and magnesium
Magnesium can reduce absorption of some antibiotics and bisphosphonates. A pharmacist can check the relevant timing and interactions for your medicine. NIH interaction reference
Interpreting a research dose
A dose used in a trial describes the experiment. The participants, eligibility rules, formulation and follow-up matter; the number alone is not a personal recommendation.
Sources & further reading
Clinical papers, nutrition references and manufacturer labels are identified separately.
- NIH ODS · Magnesium: consumer reference
- EFSA · Dietary reference values for magnesium (2015)
- Schuster et al. · Magnesium bisglycinate and poor sleep (2025)
- Lopresti et al. · Magnesium and sleep: systematic review (2026)
- Cochrane · Magnesium for skeletal muscle cramps (2020)
- NIH ODS · Magnesium: health professional reference
- EFSA / SCF · Tolerable upper intake levels, summary (2025)
