Supplements

Magnesium

3.6

Magnesium: What magnesium helps with.

4 sections, about 6 minutes in total

310–360

The NIH reference range for women is 310 to 360 mg a day. That is 310 to 320 for most adults, and 350 to 360 in pregnancy.

Constipation

Constipation is the one use with strong evidence. Sleep and PMS have small, mixed studies behind them.

Food

Food such as nuts, seeds, beans, whole grains and greens covers most people.

Section 1 of 4:

Sorting hype from fact

It is sold for more than the evidence supports.

Magnesium works for constipation. For sleep and PMS the studies are small and mixed. For cramps, anxiety and energy there is little evidence it helps.

What the marketing says

  • One capsule fixes sleep, anxiety, cramps and energy.
  • Everyone is deficient.
  • You need one special form, usually the expensive one in the video.

What the evidence shows

  • For constipation it works. Citrate and oxide are laxatives that have been used for years.
  • For sleep and PMS the studies are small and the results are mixed. It is reasonable to try it for a few weeks, as long as you do not expect much.
  • For cramps, anxiety and energy, the trials have not shown much. Getting your magnesium from food makes more sense than a capsule.
  • Most people who eat a varied diet are not deficient. Many do eat a bit less than the reference amount, but that is not the same as being deficient.

Some medications, gut conditions and heavy alcohol use can cause a real deficiency. That is a case for blood work.

Section 2 of 4:

What the evidence says

What magnesium can and cannot do.

Constipation is well established. Migraine prevention has moderate support, at a dose above the supplement upper limit. Sleep, anxiety and PMS have weak evidence. Cramps have the least.

The claimIt sorts out constipation.
What the evidence saysThis one is well supported. Citrate and oxide draw water into the gut, and they have been used as laxatives for a long time.
The claimIt prevents my migraines.
What the evidence saysThere is reasonable support here. Headache guidelines list 400 to 600 mg a day as probably effective for prevention. That is more than the 350 mg supplement upper limit, so it is not something to try on your own.
The claimIt fixes sleep.
What the evidence saysThe evidence is thin so far. The trials are small and short, and most were done in older adults or people with low intakes. Some found a benefit and some did not. Trying it for two to four weeks is reasonable, as long as you do not expect much.
The claimIt calms anxiety.
What the evidence saysThe evidence is thin here too. There are only a handful of small, short trials, and they have design problems. Some of the calming effect people notice may come from the bedtime routine itself.
The claimIt eases my PMS.
What the evidence saysThe evidence is limited. A few small trials found modest improvement in some symptoms, and others found none. A short trial with an end date is a fair way to find out if it does anything for you.
The claimIt stops muscle cramps.
What the evidence saysThis is the least supported claim. When Cochrane pooled the trials, magnesium did not appear to help with general muscle cramps.

These summaries reflect the cited research and will change if the research changes. This is coaching context, not a prescription.

Section 3 of 4:

Which form does what

The form decides the side effects.

Citrate is the usual default. Glycinate is easiest on the gut. Oxide is poorly absorbed, which is why it works as a laxative. Several other forms are sold on claims that go beyond their evidence. Tap a form to compare.

Tap a tab to open it. The detail lands here.

Whatever the form or brand, the 350 mg a day supplement upper limit applies. Third-party seals still matter.

Section 4 of 4:

The safety rules

When to check first.

If you have kidney disease, check before taking magnesium. Some medications interact with it. If you get diarrhea, you are taking too much.

  • If you have kidney disease or reduced kidney function, ask your doctor first. The kidneys clear magnesium, so it can build up.

  • If you take medications, check for interactions. Magnesium affects some antibiotics and bisphosphonates. A pharmacist can tell you about timing.

  • If you get diarrhea, the dose is too high. Gut symptoms usually appear before anything serious. Lower the dose or stop.

  • If you are trying it for sleep or PMS, give it 2 to 4 weeks at a sensible dose. Then decide based on the result.

Food is the best first option. A handful of almonds, some dal and whole grains supply more magnesium than many capsules.

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