Magnesium Glycinate vs Bisglycinate: Are They the Same?

Magnesium glycinate and magnesium bisglycinate are the same compound. Bisglycinate is the precise chemical name for one magnesium atom bound to two molecules of the amino acid glycine, and "glycinate" is the everyday shorthand. What actually differs between bottles is whether the product is buffered with other forms of magnesium.

So if you're in the supplement aisle holding a "glycinate" in one hand and a "bisglycinate" in the other, the name isn't the thing to worry about. Below I explain the words, what "chelated" and "Chelamax" mean, and the one line on the label that tells you what you're really buying. (Still choosing between forms entirely? Start with magnesium glycinate vs citrate vs oxide.)

Are magnesium glycinate and bisglycinate the same?

Chemically, yes. Glycine is the smallest amino acid, and when magnesium is bound to it, each magnesium atom holds two glycine molecules. "Bis" is the chemist's prefix for "two," so magnesium bisglycinate literally means magnesium with two glycinates. "Diglycinate" says the same thing with a different prefix. PubChem, the NIH's chemistry database, files all three names under a single compound (CID 84645), with a molecular weight of about 172.

Brands choose a name for marketing reasons. Some think "bisglycinate" sounds more technical, others think "glycinate" is more familiar. Neither name tells you anything about quality.

How much magnesium is actually in bisglycinate?

Glycine is bulky, so magnesium is only a small share of the compound's weight. In pure form, magnesium is about 14% of magnesium bisglycinate by weight. Real ingredients vary a little with water content and manufacturing. On our own label, 1,700mg of magnesium bisglycinate supplies 200mg of elemental magnesium.

That's why a real bisglycinate takes more than one capsule to reach a meaningful dose. Our serving is three. Magnesium oxide, by comparison, is about 60% magnesium by weight, which is how some brands fit a big number into one small pill.

What is chelated magnesium?

"Chelated" (say it "KEY-lated") comes from the Greek word for claw. It means the mineral is held by an organic molecule, in this case an amino acid, in a ring-shaped bond. Magnesium bisglycinate is a chelate: the glycine "claws" hold on to the magnesium.

Chelated minerals are popular because they tend to dissolve well, and the NIH Office of Dietary Supplements notes that magnesium forms that dissolve well in liquid are generally absorbed better than less soluble forms like oxide. One small study in people who'd had part of their intestine removed found magnesium diglycinate was absorbed better than magnesium oxide (Schuette and colleagues, 1994). It's a small study in a specific group, but it lines up with the solubility research.

What is Chelamax?

Chelamax is the brand name of the magnesium bisglycinate we use in NO. 04. It's made by the ingredient company Innophos, and our supply is sourced from the Dead Sea and chelated in the USA. A branded ingredient isn't magic. What it does give you is a specific, traceable raw material with its own specifications, instead of an unnamed "magnesium glycinate" from a supplier nobody will name.

One thing that surprises people: a product can use a good chelate and still be buffered if oxide is added next to it. The brand of the chelate matters less than whatever else is in the capsule.

“One thing I learned when researching magnesium is that "glycinate" and "bisglycinate" are often used interchangeably to describe magnesium bound to glycine. What mattered most to me was choosing a pure, non-buffered magnesium glycinate from a quality source, which is why we chose Chelamax for NO. 04.”

Skotie Rae, RN, founder

The label line that actually matters

Federal labeling rules for dietary supplements (21 CFR 101.36) require the Supplement Facts panel to name the source of each dietary ingredient, either in parentheses next to the amount or in the ingredient list. That's where you find out what's really inside. This is what I look for:

1. "Magnesium 200mg (as magnesium bisglycinate)" means one form, non-buffered. Whether the front says glycinate or bisglycinate doesn't matter.
2. "(as magnesium glycinate, magnesium oxide)" means a buffered blend. A lot of the magnesium may be coming from oxide.
3. "Other ingredients" shouldn't include another magnesium compound.
4. Serving size of two to four capsules for about 200mg is normal for real bisglycinate. One small capsule with a big number is a red flag.

What "glycinate chelate," "fully reacted" and "complex" mean

A few other phrases show up on labels. "Magnesium glycinate chelate" is just another way of saying bisglycinate, with an extra word. "Fully reacted" is the manufacturer saying the magnesium and glycine have completely bonded, with no loose magnesium or glycine left over. That matters, because an incompletely reacted ingredient can hold less real chelate than the label suggests. "Magnesium glycinate complex" or "glycinate blend" is the one to read closely, since it often means glycinate mixed with other forms, usually oxide.

We walk through a real panel step by step in buffered vs non-buffered magnesium glycinate.

So which should you buy, glycinate or bisglycinate?

Either name is fine. I'd choose on these three things instead:

• Non-buffered: only magnesium bisglycinate in the "as" line.
• Elemental dose: a clear elemental number that keeps your supplemental total within the NIH upper limit of 350mg a day for adults.
• Proof: third-party testing, with a Certificate of Analysis you can actually read.

That's how we built NO. 04 Magnesium Glycinate. Three capsules supply 200mg of elemental magnesium from 1,700mg of Chelamax non-buffered magnesium bisglycinate. The only other ingredients are tapioca starch and a vegetable (HPMC) capsule, and there are 90 capsules in a bottle. Every lot is tested by Contract Testing Laboratories of America, with results on our Certificate of Analysis page, and all of our product facts are on the Rae Basics facts page. If you're new to magnesium, our guide to magnesium glycinate side effects covers what to expect.

Talk to your clinician before starting magnesium if you have kidney disease, are pregnant or breastfeeding, or take prescription medicines.

Quick answers

Sources

1. National Library of Medicine, PubChem. Magnesium glycinate (CID 84645). Synonyms include magnesium bisglycinate and magnesium diglycinate; molecular weight 172.42.
2. NIH Office of Dietary Supplements. Magnesium: Fact Sheet for Health Professionals.
3. Schuette SA, Lashner BA, Janghorbani M. Bioavailability of magnesium diglycinate vs magnesium oxide in patients with ileal resection. JPEN J Parenter Enteral Nutr. 1994;18(5):430-435.
4. Code of Federal Regulations. 21 CFR 101.36, Nutrition labeling of dietary supplements.