Magnesium is one of the most recommended sleep-adjacent supplements out there — and also one of the most confusing to shop for, because the form it's bound to changes almost everything about how it behaves in your body. Glycinate, citrate, oxide, threonate, malate — same mineral, very different experience.
Why the form matters more than the mineral
Elemental magnesium is unstable on its own, so supplement manufacturers bind it to another compound (a "chelate") to make it stable and absorbable. That binding compound is the difference between a form that's gentle and well-absorbed, and one that mostly just gives you gas — or worse.
Magnesium Oxide — cheap, poorly absorbed
The most common form on drugstore shelves, mainly because it's the cheapest to manufacture. Oxide has a high elemental magnesium percentage by weight, which looks good on a label — but it's poorly absorbed by the body. Most of it passes through the gut largely unused, which is actually why oxide is more often marketed as a laxative than a sleep or relaxation aid.
Magnesium Citrate — better absorbed, but can move things along
Citrate is absorbed considerably better than oxide, and it's a reasonable general-purpose option. The tradeoff: citrate has a mild osmotic (laxative) effect for a lot of people, especially at higher doses — not ideal for something you're taking every night before bed.
Magnesium Glycinate — the one built for this
Magnesium bound to glycine (an amino acid that itself has calming properties) tends to be one of the best-tolerated, best-absorbed forms — and it's much less likely to cause the GI effects associated with citrate or oxide. That combination — good absorption, gentle on digestion, paired with a naturally calming amino acid — is exactly why glycinate shows up so often in sleep-focused formulas specifically, rather than general-purpose multivitamins.
There's a further distinction worth knowing: "buffered" versus "non-buffered" glycinate. Buffered versions are often cut with a cheaper form (like oxide) to reduce cost, which dilutes the benefits of the glycinate chelate. Non-buffered, fully-reacted glycinate is the more expensive, purer version — and it's the one we use in Night Reset, at 300mg.†
Magnesium Threonate — the newest, most studied for cognition
A newer, more expensive form specifically studied for its ability to cross the blood-brain barrier. Promising research exists, particularly around cognitive function — but the cost per effective dose is significantly higher, and for a nightly relaxation formula, the additional benefit over well-formulated glycinate hasn't been clearly established for sleep specifically.
The label check
When you're comparing magnesium products, skip past "Magnesium 500mg" on its own — that number is meaningless without knowing the form. Look for the specific compound name in parentheses: "(as Magnesium Glycinate)" tells you far more than the milligram number next to it.
†These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.