Guide
Glycine vs magnesium glycinate: they're not the same supplement
Magnesium glycinate is magnesium chelated to glycine, so it does contain glycine — but the amount isn't usually printed, and it isn't dosed the way a standalone glycine supplement is.
Glycine and magnesium glycinate are related but not interchangeable. Magnesium glycinate is magnesium chelated to two molecules of glycine, so taking it does deliver some glycine — but the amount is rarely printed on the label, and a magnesium glycinate serving is dosed to hit a magnesium target, not a glycine one. The two are worth telling apart before you compare a magnesium label against a glycine one.
What glycine actually is
Glycine is the smallest amino acid, one of the twenty the body uses to build protein, and it's sold on its own as a supplement, usually as a plain powder or capsule with no magnesium attached at all. Magnesium glycinate is a different product: one magnesium ion bound to two glycine molecules, sold specifically as a way to deliver magnesium. Reading "glycinate" on a magnesium bottle tells you which amino acid the magnesium is chelated to. It does not mean the product is a glycine supplement, or that it is dosed the way one would be.
How much glycine is actually in magnesium glycinate
Magnesium glycinate's molecular weight is 172.42 g/mol (PubChem CID 84645): magnesium accounts for 24.3 of that, and the two glycine units account for the rest — roughly 86% of the compound's weight in a fully-reacted, anhydrous chelate. Put another way, for every gram of elemental magnesium a fully-reacted glycinate chelate delivers, it's carrying somewhere in the range of six grams of glycine alongside it.
That's the chemistry for the compound in general. It isn't a number we print for our own product: our label states the elemental magnesium (275 mg) and the compound weight (2,500 mg) it comes from, the same way most magnesium glycinate labels do, and it does not list glycine as a separate ingredient. If a precise glycine figure matters to you, a glycine supplement dosed and labeled as glycine is the more direct way to get one.
Why the two get confused
Glycine on its own has been studied for sleep at gram-scale doses taken as glycine, not as part of a magnesium chelate. That research doesn't transfer to a magnesium glycinate serving, because the amount of glycine you get from a magnesium supplement is set by how much magnesium the label is dosing you to, not by a glycine target.
This overlap has muddied some of the magnesium research too. A 2025 randomized trial gave 250 mg of elemental magnesium as bisglycinate to adults reporting poor sleep and found a small improvement on one insomnia score, with no significant improvement on any other measure. At that dose, a fully-reacted glycinate chelate would also be delivering somewhere around 1,500 mg of glycine alongside the magnesium — which is exactly why the trial's own result can't be cleanly credited to magnesium. Glycine could be doing some of the work, all of it, or none of it; the design doesn't separate the two. We go through the sleep evidence in full, magnesium and glycine both, in Magnesium glycinate and sleep: what the evidence shows.
Glycine vs magnesium glycinate, side by side
| Glycine (standalone) | Magnesium glycinate | |
|---|---|---|
| What it is | An amino acid, sold on its own | Magnesium chelated to two glycine molecules |
| What it's dosed to | A glycine target, usually gram-scale | An elemental magnesium target, usually a few hundred milligrams |
| Glycine delivered | The full labeled amount | A byproduct of the magnesium dose; rarely printed separately |
| Typical label | States glycine in grams | States elemental magnesium and compound weight; glycine usually absent |
Questions people ask
Is glycine the same as magnesium glycinate?
No. Glycine is a single amino acid sold on its own. Magnesium glycinate is magnesium bound to two glycine molecules, sold to deliver magnesium. Taking one is not the same as taking the other.
Does magnesium glycinate contain glycine?
Yes — that's what defines the compound. But most labels, including ours, print the elemental magnesium and the compound weight, not a separate glycine amount.
How much glycine is in magnesium glycinate?
In a fully-reacted, anhydrous chelate, glycine makes up most of the compound's weight — roughly six times the elemental magnesium by weight. The exact figure for any specific product depends on whether the material is anhydrous or hydrated and isn't something most labels state directly.
Can you take glycine and magnesium glycinate together?
There's no specific evidence against it that we're aware of; you'd simply be getting glycine from both. If you're combining several supplements, check with your doctor or pharmacist, particularly if you take prescription medication.
Does magnesium glycinate act as a glycine supplement for sleep?
Not on the evidence available. The trial closest to a typical magnesium glycinate serving found a marginal result on one measure and none on the others, and it can't separate the magnesium from the glycine that came with it. We don't make a sleep claim for our product. The full picture is in our sleep evidence review, linked above.
Sources
- Magnesium glycinate, C4H8MgN2O4, 172.42 g/mol: PubChem CID 84645.
- Glycine, C2H5NO2, 75.07 g/mol: PubChem CID 750.
- Magnesium Bisglycinate Supplementation in Healthy Adults Reporting Poor Sleep: A Randomized, Placebo-Controlled Trial. PMID 40918053.
- Magnesium glycinate and sleep: what the evidence shows.
- Chelated, buffered and lysinate glycinate: what these magnesium label terms mean.
Sources
- Magnesium Bisglycinate Supplementation in Healthy Adults Reporting Poor Sleep: A Randomized, Placebo-Controlled Trial In 155 adults sleeping poorly, 250 mg a day for four weeks improved one insomnia score slightly; other sleep measures did not change.
*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.