Magnesium Glycinate vs Bisglycinate: Are They the Same?
Published Updated Ben Law
Reviewed by Sarah Law, Dip CNM, Naturopathic Nutritionist
Magnesium glycinate vs bisglycinate: they are the same compound. Magnesium bisglycinate is the chemical name for magnesium bound to two ("bis") molecules of the amino acid glycine, and magnesium glycinate is the shorter everyday name for it. What actually separates two products with either name on the front is whether the powder inside is pure bisglycinate (unbuffered) or bisglycinate blended with cheaper magnesium oxide (buffered). Pure bisglycinate holds at most about 14.1% magnesium by weight, so if elemental magnesium divided by the compound weight on a label comes out higher than that, something other than glycinate is supplying part of the dose.
Our own label is the worked example on this page. Love Life Supplements Magnesium Glycinate is printed as a pure, unbuffered chelate: 2,750 mg of magnesium glycinate (bisglycinate) supplying 303 mg of elemental magnesium per four capsules, which is 11% and well under the 14.1% ceiling. A 240-capsule tub is a 60-day supply at £37.95 in the UK and $51.47 in the US, about 63p or 86 cents a day. Every batch is third-party tested, the latest Eurofins report confirmed the 303 mg figure within the lab's measurement uncertainty, and each tub carries our 60-day guarantee.
- Same compound, two names: glycinate, bisglycinate and diglycinate all mean magnesium bound to two glycines. The name on the tub tells you nothing about quality.
- Buffered vs unbuffered is the real difference: buffered products add magnesium oxide to pack more milligrams into each capsule; unbuffered products contain bisglycinate only.
- The 14.1% rule: divide elemental magnesium by compound weight. Above about 14.1%, another magnesium source must be present.
- Capsule maths: pure bisglycinate cannot deliver 400 to 500 mg of magnesium in one or two standard capsules. That claim needs oxide.
- Dose by elemental magnesium: UK NRV 375 mg and NHS guidance of 400 mg or less a day from supplements; US NIH RDA 310 to 420 mg from all sources, with a 350 mg upper limit for supplements.
Is magnesium glycinate the same as magnesium bisglycinate?
Yes. Magnesium glycinate and magnesium bisglycinate are two names for one compound, and you can regard them as identical when you compare labels. "Bis" is the chemistry prefix for two: in magnesium bisglycinate a single magnesium atom is held between two glycine molecules, each attached through both its amino group and its acid group, which closes two small rings around the mineral. That ring structure is what makes it a chelate.
Because the 2 : 1 form is the only one sold as a supplement ingredient in any volume, manufacturers use the names loosely. You will see "magnesium glycinate", "magnesium bisglycinate", "magnesium glycinate (bisglycinate)", "magnesium bisglycinate chelate" and, in older research, "magnesium diglycinate". The ileal resection study often quoted for this form, for example, called its material magnesium diglycinate [3]. Our product is listed as "Magnesium Glycinate (Bisglycinate)" for exactly this reason: people search for both names and both are correct.
So when someone asks which is better, magnesium glycinate or bisglycinate, the answer is that the question is the wrong one. Two tubs can carry either name and be very different products, because one can be pure chelate and the other can be partly magnesium oxide. The rest of this guide shows you how to tell them apart from the label alone.
What do the words on a magnesium glycinate label mean?
Most of the terms on a magnesium glycinate label describe the same chemistry in different words; only three of them change what you are buying: buffered, the elemental figure, and the ingredients list. This glossary covers the terms you will meet on UK, EU and US labels and what each one does and does not tell you.
| Label term | What it means | Does it tell you if oxide was added? |
|---|---|---|
| Magnesium glycinate | Everyday name for magnesium bound to glycine; in practice the 2 : 1 bisglycinate | No |
| Magnesium bisglycinate | Precise name: one magnesium, two glycines | No |
| Magnesium diglycinate | Older or more formal synonym for bisglycinate | No |
| Chelate / chelated | The mineral is held in a ring by the amino acid. Bisglycinate is a chelate by definition | No: a buffered blend still contains chelate |
| Fully reacted | The magnesium and glycine have been reacted to completion, leaving little free glycine or unreacted magnesium | Partly: it describes the chelate, not what was blended in afterwards |
| Buffered | Bisglycinate blended with another magnesium source, usually magnesium oxide, to raise the magnesium per gram | Yes: buffered means something else was added |
| Unbuffered / non-buffered / pure chelate | All of the magnesium comes from bisglycinate | Yes: no oxide, if the numbers agree |
| Elemental magnesium | The weight of magnesium itself, the figure that counts towards your intake and the NRV or RDA | Yes, when you compare it with the compound weight |
| "Magnesium (from magnesium bisglycinate)" | Only the elemental figure is printed, with no compound weight | Not on its own: check the ingredients list and the capsule size |
| Our label | "Magnesium Glycinate 2750mg, of which Magnesium 303mg", printed "Pure Chelate, Unbuffered" | Yes: 303 / 2,750 = 11.0%, consistent with pure bisglycinate |
Terms as they appear on supplement labels sold in the UK, EU and US. "Our label" row transcribed from the current Love Life Supplements Magnesium Glycinate 240-capsule label.
Buffered vs unbuffered magnesium glycinate: what is the difference?
Buffered magnesium glycinate is bisglycinate mixed with another magnesium compound, almost always magnesium oxide; unbuffered magnesium glycinate is bisglycinate on its own. The reason to buffer is arithmetic. Oxide is about 60% magnesium by weight against about 14% for bisglycinate, so adding oxide lets a brand print a bigger milligram figure on fewer capsules, at a lower raw material cost per milligram.
The trade-off is that oxide is the form people are usually trying to avoid when they choose glycinate. In a laboratory comparison of US magnesium preparations, magnesium oxide showed a fractional absorption of about 4%, the lowest of the forms tested [1]. In a 60-day randomised trial in 46 adults taking 300 mg of elemental magnesium a day, an amino-acid chelate and citrate raised urinary magnesium more than oxide, and oxide was no different from placebo [2]. In 12 patients with ileal resection, magnesium diglycinate was absorbed at least as well as oxide overall, better in the patients with the most impaired absorption, and was better tolerated [3]. Unabsorbed magnesium stays in the gut and draws water with it, which is why higher oxide content tends to mean looser stools.
The part most people miss is how quickly oxide takes over. Because oxide carries more than four times as much magnesium per gram, a small amount by weight supplies a large share of the dose. Blend bisglycinate and oxide 50 : 50 by weight and the mix is about 37% magnesium, but roughly 81% of that magnesium comes from the oxide. A product can list "magnesium bisglycinate" first on its ingredients and still deliver most of its magnesium as oxide.
Buffering is not unsafe and it is not illegal, provided the label lists every ingredient. The issue is value and expectation: if you are paying a glycinate price because you want the glycinate form, a buffered product gives you less of it than the front of the tub suggests.
How much elemental magnesium is in magnesium bisglycinate?
Pure, anhydrous magnesium bisglycinate is about 14.1% magnesium by weight, calculated from its molecular weight (24.3 g of magnesium in 172.4 g of compound). Commercial materials usually come in lower, at roughly 10 to 14%, because the powder carries some bound water (the dihydrate is about 11.7% magnesium) and a little free glycine. That gives you a hard ceiling: no pure bisglycinate can exceed about 14.1%, and an unbuffered label will usually show something between 10 and 14%.
The table below is the original data on this page. It shows what a given elemental percentage on a label tells you, and the minimum share of the magnesium that must be coming from oxide if the extra comes from oxide. "Minimum" because it assumes the most magnesium-rich possible glycinate; with a typical commercial grade, the oxide share is higher still.
| Elemental % on the label (elemental mg / compound mg) | Example label | Can pure bisglycinate explain it? | Oxide by weight, at least | Share of the magnesium from oxide, at least |
|---|---|---|---|---|
| 11.0% | Love Life Supplements: 2,750 mg glycinate, 303 mg magnesium per 4 capsules | Yes | 0% | 0% |
| 14.1% | Theoretical maximum for anhydrous bisglycinate | Yes, just | 0% | 0% |
| 18% | 1,000 mg "glycinate", 180 mg magnesium | No | 8% | 28% |
| 20% | 1,000 mg "glycinate", 200 mg magnesium | No | 13% | 39% |
| 25% | 800 mg "glycinate", 200 mg magnesium | No | 24% | 57% |
| 30% | 1,000 mg "glycinate", 300 mg magnesium | No | 34% | 69% |
| 37% | 50 : 50 bisglycinate and oxide by weight | No | 50% | 81% |
Calculated with theoretical magnesium contents of 14.1% for anhydrous magnesium bisglycinate and 60.3% for magnesium oxide. Example labels are illustrative patterns, not named products. If the glycinate used is a hydrated commercial grade (about 11 to 12%), the oxide figures in the last two columns are higher than shown.
Price per 100 mg of elemental magnesium (our product, checked 16 October 2026)
- Love Life Supplements Magnesium Glycinate, UK store: £37.95 for 60 servings of 303 mg = 18,180 mg of magnesium, so 20.9p per 100 mg and about 63p a day.
- Same product, US store: $51.47 for the same 18,180 mg, so 28.3 cents per 100 mg and about 86 cents a day.
- How to use this: work out the same figure for any product you are comparing (price divided by total elemental milligrams in the tub, times 100). A buffered product will often look cheaper per 100 mg; the table above tells you how much of that magnesium is oxide.
How can you tell if magnesium glycinate is buffered?
You can usually tell from the label in under a minute: divide the elemental magnesium by the compound weight, read the ingredients list, and check that the capsule count makes physical sense. If all three agree with pure bisglycinate, the product is unbuffered. Use the checker below, then run through the five checks underneath it.
Buffered or unbuffered? Label check
Enter the compound weight (the "magnesium glycinate" or "bisglycinate" figure) and the elemental magnesium for the same serving, both in mg.
Uses a 14.1% ceiling for pure anhydrous bisglycinate and 60.3% for magnesium oxide. A result under the ceiling does not prove purity on its own; read the ingredients list too.
- Do the percentage. Elemental magnesium divided by compound weight. Between about 10 and 14% is consistent with pure bisglycinate; above 14.1% means another magnesium source is present. If the label prints only the elemental figure, move to checks 2 and 3.
- Read the full ingredients list. Magnesium oxide, magnesium citrate, magnesium carbonate or "magnesium (as oxide and bisglycinate)" means a blend. Some labels say "buffered" outright; most do not.
- Do the capsule maths. A size 00 capsule, the largest most brands use, holds roughly 700 to 900 mg of a powder like this; ours carry 687.5 mg of glycinate each. At 14.1%, that is no more than about 100 to 125 mg of magnesium per capsule. A claim of 400 to 500 mg of magnesium "from bisglycinate" in two capsules would need more than 1.4 g of glycinate per capsule, which does not fit.
- Look for the Certificate of Analysis. A brand that publishes a recent third-party assay of magnesium content per serving gives you a measured number to set against the label. Ours is published on the product page: Eurofins confirmed 302 mg against the 303 mg declared, within the lab's measurement uncertainty, and quantified lead at 0.10 mg/kg against an EU limit of 3.0 mg/kg.
- Be wary of a glycinate that is unusually cheap per 100 mg. Price per 100 mg of elemental magnesium is a fair comparison only between products of the same form. A glycinate costing far less than its unbuffered peers per 100 mg is often a buffered one.
Our magnesium glycinate buyer's guide applies these checks to eight products on sale today, and how we test and verify magnesium glycinate purity explains what the lab measures on our batches.
"When a client brings me a magnesium label, I ignore the name on the front and divide the elemental figure by the compound weight. If that comes out above about 14%, some of the magnesium is coming from another form, whatever the tub calls itself."
Sarah Law, Naturopathic Nutritionist | Optimised Female
Is buffered magnesium glycinate bad?
No, buffered magnesium glycinate is not harmful; it is simply a different product from pure glycinate, with more of its magnesium as oxide. For someone who wants the most milligrams in the fewest capsules and is not bothered about the form, a buffered product can be a reasonable choice. The case for unbuffered rests on three points.
- You get the form you chose. The human studies that favour glycinate over oxide compared the two head to head [2] [3]. A blend that is mostly oxide by magnesium content behaves more like oxide.
- Gentler on the stomach. Loose stools are the most common reason people stop taking magnesium, and oxide is the usual culprit at higher doses. Glycinate is chosen precisely because it is well tolerated.
- The label means what it says. With an unbuffered product, the name on the front, the compound weight and the elemental figure all describe the same thing, so price per 100 mg is a like-for-like number.
The cost of unbuffered is more capsules. Ours takes four capsules for 303 mg because each capsule holds 75.75 mg of magnesium; that is simply the arithmetic of a 10 to 14% compound, and it is why you can split the serving across the day. If swallowing four capsules is the obstacle, our capsules vs powder guide covers the alternatives.
Which magnesium glycinate should you buy?
Buy an unbuffered magnesium bisglycinate whose label prints both the compound weight and the elemental magnesium, whose percentage lands between about 10 and 14%, and whose maker publishes a recent third-party assay. Then compare on price per 100 mg of elemental magnesium. Whether the tub says glycinate or bisglycinate does not matter.
That is the standard we set for our own. Love Life Supplements Magnesium Glycinate is printed "Pure Chelate, Unbuffered" and declares both figures: 2,750 mg of magnesium glycinate and 303 mg of magnesium per four capsules (81% of the UK NRV). The 240 vegan capsules make a 60-day supply, at £37.95 on our UK store and $51.47 on our US store. It is made in the UK under a GMP licence, every batch is third-party tested, the Certificate of Analysis is published on the product page, and every tub carries a 60-day guarantee. Magnesium contributes to normal muscle function, normal functioning of the nervous system, normal psychological function and the reduction of tiredness and fatigue [6].
Unbuffered and fully declared: Magnesium Glycinate (Bisglycinate), 2,750 mg glycinate giving 303 mg elemental magnesium per serving, 60-day supply, third-party tested.
See the labelIf you want glycinate as one part of broader cover, Magnesium Seven combines bisglycinate with six other forms for 329 mg of elemental magnesium per serving. How those forms compare is in magnesium glycinate vs threonate vs taurate vs malate, and glycinate against the two forms it is most often confused with is in magnesium glycinate vs citrate vs oxide.
How much magnesium glycinate should you take per day?
Dose by elemental magnesium, never by compound weight: 2,750 mg of glycinate sounds like a lot but supplies 303 mg of magnesium. Most adults taking a supplement aim for roughly 200 to 350 mg of elemental magnesium a day, on top of food. The reference figures differ between the UK and the US, and they are not the same kind of number, so this table sets them side by side.
| Figure | UK | US |
|---|---|---|
| Label reference value | NRV 375 mg a day (adults) | FDA Daily Value 420 mg a day (adults) |
| Recommended intake from all sources | NHS: 300 mg a day for men, 270 mg for women (19 to 64) | NIH RDA: men 400 mg (19 to 30) and 420 mg (31+); women 310 mg (19 to 30) and 320 mg (31+) |
| Upper figure for supplements | NHS: 400 mg or less a day from supplements is unlikely to cause harm; EFSA tolerable upper level 250 mg a day from supplements | NIH tolerable upper intake level 350 mg a day from supplements (adults) |
| Our serving (4 capsules) | 303 mg = 81% of the NRV | 303 mg = 72% of the Daily Value |
Sources: NHS [5]; NIH Office of Dietary Supplements [4]; EFSA [7]. Upper levels apply to supplements and medicines, not to magnesium from food.
Our label says take up to four capsules daily with food, so you can start with one or two and build up. Full detail on dosing, splitting the serving and timing is in how much magnesium glycinate per day.
"I usually suggest starting with one or two capsules with food and building up over a week or two. Splitting the serving between morning and evening is gentler on the stomach and makes the habit easier to keep."
Sarah Law, Naturopathic Nutritionist | Optimised Female
Who should take care with magnesium glycinate?
Most healthy adults can take magnesium glycinate within the amounts above, but some people should get advice first. Healthy kidneys clear magnesium the body does not need, so anyone with reduced kidney function should not supplement without their doctor's agreement [4]. Magnesium can reduce the absorption of some antibiotics (tetracyclines and quinolones), bisphosphonates and levothyroxine, so those are usually taken a few hours apart. If you are pregnant or breastfeeding, speak to your doctor or midwife before taking any magnesium supplement. Our label is not intended for under-18s. The full list is in who should not take magnesium, and what daily use looks like over weeks and months is in what happens if you take magnesium glycinate every day.
Frequently asked questions
Is magnesium bisglycinate the same as magnesium glycinate?
Yes. Magnesium bisglycinate is the precise chemical name and magnesium glycinate is the everyday name for the same compound: one magnesium atom bound to two molecules of the amino acid glycine. Labels, retailers and researchers use the two names interchangeably, along with magnesium diglycinate. What differs between products is not the name but whether the powder is pure bisglycinate or has been buffered with magnesium oxide.
Which is better, magnesium glycinate or bisglycinate?
Neither, because they are the same thing. The useful question is whether the product is unbuffered (pure bisglycinate) or buffered (bisglycinate blended with magnesium oxide to raise the milligrams per capsule). Check the elemental percentage: divide the elemental magnesium by the compound weight. Pure bisglycinate cannot exceed about 14.1%, so a higher figure means another magnesium source is in the capsule.
What does non-buffered magnesium glycinate mean?
Non-buffered, or unbuffered, means every milligram of magnesium in the capsule comes from magnesium bisglycinate, with no magnesium oxide or other salt mixed in. It usually means more capsules per day, because bisglycinate carries only 10 to 14% magnesium by weight. Love Life Supplements Magnesium Glycinate is printed as a pure, unbuffered chelate: 2,750 mg of magnesium glycinate supplying 303 mg of magnesium across four capsules.
Is chelated magnesium glycinate the same as magnesium bisglycinate?
Yes. A chelate is a mineral held in a ring by an amino acid, and magnesium bisglycinate is a chelate by definition, so chelated magnesium glycinate, magnesium glycinate chelate and magnesium bisglycinate chelate all describe the same compound. The word chelated on its own does not tell you whether oxide has been added; the elemental percentage does.
How much elemental magnesium is in magnesium bisglycinate?
About 14.1% by weight in theory, for the pure anhydrous compound, and typically 10 to 14% in commercial materials, which carry some water and glycine. So 1,000 mg of magnesium bisglycinate gives roughly 100 to 141 mg of elemental magnesium. The Love Life Supplements label works out at 11%: 2,750 mg of compound for 303 mg of magnesium per serving.
How much chelated magnesium glycinate should I take per day?
Dose by elemental magnesium, not compound weight. Most labels sit between 200 and 350 mg of elemental magnesium a day. In the UK the NHS says 400 mg or less a day from supplements is unlikely to cause harm and the NRV is 375 mg; in the US the NIH sets the upper limit for supplemental magnesium at 350 mg a day for adults. Start lower if your stomach is sensitive and speak to your doctor if you have kidney problems, take regular medication, or are pregnant or breastfeeding.
About the Reviewer: Sarah Law, Dip CNM
Sarah Law is a Certified Naturopathic Nutritionist and Functional Practitioner specialising in hormonal health, gut health, and evidence-based nutrition. She holds a Diploma in Naturopathic Nutrition from the College of Naturopathic Medicine (CNM, London) and is a Certified Functional Health Coach. Sarah combines naturopathic principles with modern functional nutrition science to help her clients make informed health decisions.
About the Author: Ben Law
Ben Law is the founder of Love Life Supplements and host of the Optimised Health Show. A qualified Advanced Dietary Supplement Advisor and Primal Blueprint Certified Expert, he has spent over a decade building transparent, research-led formulations made to GMP and BRC standards. Learn more about Ben.
References
- Firoz M, Graber M. Bioavailability of US commercial magnesium preparations. Magnes Res. 2001;14(4):257-62. PubMed
- Walker AF, Marakis G, Christie S, Byng M. Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study. Magnes Res. 2003;16(3):183-91. PubMed
- 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):430-5. PubMed
- National Institutes of Health, Office of Dietary Supplements. Magnesium: Fact Sheet for Health Professionals. NIH ODS
- NHS. Vitamins and minerals: others (magnesium). NHS
- Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register. GOV.UK
- Scientific Committee on Food, Scientific Panel on Dietetic Products, Nutrition and Allergies. Tolerable upper intake levels for vitamins and minerals. EFSA, 2006. EFSA
Love Life Supplements is a supplement company founded by Ben Law, with stores serving the UK and the US. This guide was written from the studies listed above and from our own label and batch data; it is general information, not medical advice. Our magnesium products are made in the UK under a GMP licence, third-party tested batch by batch, and covered by a 60-day guarantee.