🧪 Supplement
magnesium
An essential mineral and top-selling supplement. Well-supported for improving glycemic control (mainly in deficiency or diabetes) and as an osmotic laxative for constipation; a modest but real effect on blood pressure and on migraine prevention; weaker, low-certainty evidence for sleep; and the best evidence leans against it for idiopathic muscle cramps.
5 well-supported · 1 disputed. This shows how settled each sub-question is, not whether magnesium is "good." Direction lives in each claim below.
The 6 claims about magnesium
Each keeps its own verdict — we never average them away.
Does magnesium relieve constipation?
Strong support Yes—magnesium oxide is a genuine osmotic laxative with solid trial support, one of magnesium's best-established uses.
Does magnesium supplementation actually improve blood sugar control?
Strong support Yes—especially if you're magnesium-deficient or have type-2 diabetes it lowers fasting glucose and insulin resistance, though the HbA1c effect is small and replete people see little.
Can magnesium help prevent migraines?
Strong support Reasonably yes—multiple trials support oral magnesium for migraine prophylaxis, with a modest but consistent effect.
Can taking magnesium lower your blood pressure?
Leans support Modestly—roughly 2–3 mmHg in most people (more in those with hypertension, diabetes or low magnesium), so real but small.
Does magnesium really help you sleep better?
Leans support Weakly—small short trials lean positive but the one meta-analysis rated the evidence low-certainty, so it's far from the sure thing the marketing implies.
Does magnesium stop muscle cramps?
Leans against Probably not—the best evidence (a Cochrane review) finds little to no benefit for the common night-time/idiopathic leg cramps.
Educational only, not medical advice. Hub descriptions are curated for honesty; see the methodology.