Magnesium

Supplements · Minerals · Supplement, Typed Supps

Your body uses it in hundreds of everyday jobs.

Stage by stage

Intake (Capsule or powder): Glycinate is gentle on the gut; citrate absorbs well but can loosen stools at higher doses.
Digestion & absorption (Passive + active transport): Magnesium salts dissolve in stomach acid, then cross the gut wall both passively and through dedicated channels in the small intestine.
Bloodstream (Mostly free-floating): Travels the blood unbound, ready for any cell that needs it.
Muscle & nerve cells (Regulates signalling): Helps relax muscle fibres and steady nerve signalling.

Correcting a documented deficiency — strong evidence. Straightforward, though true deficiency is usually driven by medication, alcohol, or gut disease rather than diet alone.
Relieving constipation — strong evidence. The osmotic forms work reliably — this is a pharmacological effect rather than a nutritional one.
Improving sleep quality — limited evidence. Popular, but the trials are small, short, and often in older adults who were deficient. Not established in healthy people with normal levels.
Reducing migraine frequency — moderate evidence. Enough supporting evidence that several headache bodies list it as an option, typically at doses above the general upper limit and under medical supervision.
Reducing muscle cramps — insufficient evidence. Trials in older adults and pregnancy have mostly found no benefit, despite how widely it is recommended for this.

200–400 mg daily of elemental magnesium

Upper limit: 350 mg daily from supplements only — food magnesium is not capped

Any time of day; some prefer evening for its mild calming effect.

Tetracycline and quinolone antibiotics: Magnesium binds them in the gut and reduces their effectiveness. Separate by several hours. (high)
Bisphosphonates: Absorption is significantly reduced. Separate by at least two hours. (high)
Proton pump inhibitors: Long-term use lowers magnesium — a reason you might need it, but also worth monitoring properly. (moderate)

“Magnesium instantly stops any cramp.” In reality: Only helps if you’re actually low — well-nourished people notice little extra effect.