Magnesium glycinate vs citrate — which one for sleep?

Reading mixed advice on this. Some say glycinate is better absorbed and gentler, others say citrate is fine and cheaper. For sleep specifically — does the form actually matter?

For sleep: glycinate has the slight edge, but it's smaller than the marketing on most supplement sites suggests. Bioavailability of both is roughly comparable in head-to-head studies (Firoz & Graber 2001 is the classic reference). Glycinate is gentler on the GI tract — citrate at higher doses (>400mg) has a real laxative effect for some people.

If sleep is your goal: 200-400mg glycinate 30-60 min before bed is the standard recommendation. If you're using magnesium primarily for constipation prevention, citrate.

+1 to glycinate for sleep specifically. The glycine half of the molecule is itself mildly relaxing/sedating. So you're getting magnesium + a calming amino acid in one. Citrate doesn't have that bonus.

One thing to flag: blood-test serum magnesium is a poor proxy for actual magnesium status (most magnesium is intracellular). If you suspect deficiency, RBC magnesium is a slightly better test, though imperfect.

Practical: I take 300mg glycinate ~45 min before bed and don't notice the laxative side effect I had on citrate. Cost difference is real but small (~$5/mo). Given the GI tradeoff alone glycinate is worth it for me.

Quality reminder same as the creatine thread last week: there's a lot of underdosed magnesium out there. Look for brands with USP verification or third-party testing. Bulk Supplements, Pure Encapsulations, Thorne, KAL all reliably test out at advertised dose.

Got it — going with glycinate, ~250mg before bed, USP-verified brand. Thanks all.