Is 500 mg of magnesium too much?
500 milligrams of magnesium is above the adult upper limit of 350 milligrams a day from supplements (magnesium in food does not count). Adults need 400 to 420 milligrams for men and 310 to 320 milligrams for women, from food and supplements together. Doctors sometimes advise more for a set time, so check with yours before taking this much.
General information, not medical advice. Check with a doctor or pharmacist before taking a supplement, especially if you are pregnant or breastfeeding, take any medicine, or are under 18.
In the UK
500 milligrams of magnesium is above the NHS guidance of 400 milligrams a day from supplements. In the UK, adults need 300 milligrams a day for men and 270 milligrams for women. Doctors sometimes advise more for a set time, so check with yours before taking this much.
The figures
| US (NIH) | UK (NHS) | |
|---|---|---|
| Amount checked | 500 mg | |
| Answer | Above the upper limit | Above NHS guidance |
| Compared with | 350 milligrams a day from supplements (magnesium in food does not count) | 400 milligrams a day from supplements |
| Share of the limit | 143% of the limit | 125% of the limit |
| Adults need | 400 to 420 milligrams for men and 310 to 320 milligrams for women, from food and supplements together | 300 milligrams a day for men and 270 milligrams for women |
Good to know
- Above the upper limit, magnesium supplements often cause diarrhoea and stomach cramps.
Quick answers
- Is 500 mg of magnesium too much?
- 500 milligrams of magnesium is above the adult upper limit of 350 milligrams a day from supplements (magnesium in food does not count). Adults need 400 to 420 milligrams for men and 310 to 320 milligrams for women, from food and supplements together. Doctors sometimes advise more for a set time, so check with yours before taking this much.
- What does the NHS say about 500 mg of magnesium?
- 500 milligrams of magnesium is above the NHS guidance of 400 milligrams a day from supplements. In the UK, adults need 300 milligrams a day for men and 270 milligrams for women. Doctors sometimes advise more for a set time, so check with yours before taking this much.
- What is the upper limit for magnesium?
- US: 350 milligrams a day from supplements (magnesium in food does not count). UK (NHS): 400 milligrams a day from supplements.
Sources
- NIH Office of Dietary Supplements fact sheet
https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/ - NHS vitamins and minerals guidance
https://www.nhs.uk/conditions/vitamins-and-minerals/others/
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More on magnesium
- Magnesium: what it does and how much you need
- Is 400 mg of magnesium too much?
- Is 500 mg of magnesium glycinate too much?