Magnesium
Guides, research reviews, comparisons, product recommendations and FAQs for magnesium.
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Start with Magnesium
Magnesium Guide
Evidence-based beginner and intermediate guide.
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Ranked recommendations and affiliate product options.
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Compare benefits, timing, dosage and alternatives.
Explore ->Magnesium FAQs
Practical answers to common questions.
Explore ->What the Research Says
Frequently Asked Questions
What is the best form of magnesium?
Glycinate and bisglycinate are best for sleep, anxiety, and general magnesium repletion — high bioavailability, minimal laxative effect. Citrate is well-absorbed and useful for constipation. Malate is preferred for energy and muscle function. Oxide has poor bioavailability (~4%) and is mostly used as a laxative — avoid for supplementation goals.
How much magnesium should I take?
The RDA is 310–420mg/day (varies by age and sex). Most people get 200–250mg through food, so 200–400mg supplemental magnesium glycinate/bisglycinate brings most people into range. For sleep specifically, 200–400mg of glycinate 1 hour before bed is the studied dose range.
Does magnesium help with sleep?
Yes — with an important caveat. Magnesium helps most in people who are deficient or insufficient (estimated 45–50% of adults). The mechanism involves GABA receptor activation (promotes relaxation) and melatonin pathway support. If you already have optimal magnesium status, additional supplementation may not add further sleep benefit.
Can I take magnesium every day?
Yes. Magnesium is water-soluble — the body excretes excess through urine. Daily supplementation at 200–400mg is safe for most adults. The UL (tolerable upper intake) is 350mg supplemental per day (not counting dietary intake). The main side effect at higher doses is loose stools (more likely with oxide or citrate than glycinate).
Does magnesium interact with other supplements?
Zinc and magnesium compete for absorption at high doses — separate them if taking large amounts of both. Vitamin D increases magnesium demand (and vice versa). Calcium-magnesium balance matters: high calcium without adequate magnesium can impair magnesium function. Taking them with food generally minimizes competition.