Magnesium Glycinate vs Magnesium Bisglycinate: Are They the Same Thing?
Is magnesium glycinate the same as magnesium bisglycinate? Yes. Magnesium glycinate and magnesium bisglycinate are two names for the same compound: magnesium bound to two molecules of the amino acid glycine. "Bisglycinate" is the precise chemical name often used on UK and EU labels, while "glycinate" is the shorter name most people search for. The one difference worth checking is whether a product is "fully reacted" or "buffered" with other forms of magnesium.
- Magnesium glycinate and magnesium bisglycinate are the same compound.
- "Bis" means two: one magnesium ion is bound to two glycine molecules.
- It is a chelated form of magnesium, often chosen because it is gentle on the stomach.
- Some products labelled "glycinate" are buffered, meaning they also contain other forms such as magnesium oxide.
- The UK Nutrient Reference Value (NRV) for magnesium is 375mg a day.
- NHS guidance says taking 400mg or less of supplemental magnesium a day is unlikely to cause harm.
Why does magnesium glycinate have two names?
Magnesium glycinate is magnesium bound to the amino acid glycine. The technically precise name is magnesium bisglycinate, because each magnesium ion is bound to two glycine molecules ("bis" simply means twice). Chemists and UK and EU labels tend to use the precise form, which is why you will often see "magnesium bisglycinate" on packaging sold here.
"Magnesium glycinate" is what most people say and search for, driven largely by US content and social media, where the shorter name dominates. Different name on the label, different name in the search bar, same compound in the capsule. Because the magnesium is bound to an amino acid, this is known as a chelated form of magnesium.
Magnesium glycinate vs bisglycinate vs buffered: what's the difference?
| Term | What it means | What to look for |
|---|---|---|
| Magnesium glycinate | The common name for magnesium bound to glycine | Check the ingredients list for the exact form |
| Magnesium bisglycinate | The precise chemical name for the same compound | Often the name used on UK and EU labels |
| Fully reacted bisglycinate | All the magnesium is bound to glycine | Ingredients list magnesium bisglycinate only |
| Buffered glycinate | Bisglycinate blended with other magnesium forms, commonly magnesium oxide | A second magnesium form in the ingredients list |
What is buffered magnesium glycinate?
Glycine is a relatively heavy molecule, so pure magnesium bisglycinate contains a fairly modest amount of magnesium per gram. To fit more magnesium into each capsule, some manufacturers blend it with other forms, most commonly magnesium oxide. These buffered products can still be sold as "magnesium glycinate". That is not necessarily a problem, but if you have chosen the glycinate form for its gentleness, it is worth reading the ingredients list to see exactly what you are getting.
What does magnesium do in the body?
Magnesium is one of the hardest-working minerals in the body, involved in hundreds of enzyme processes. Under UK and EU regulations, magnesium's recognised roles include contributing to:
- A reduction of tiredness and fatigue
- Normal psychological function
- Normal functioning of the nervous system
- Normal muscle function
- Electrolyte balance
- Normal energy-yielding metabolism
- The maintenance of normal bones and teeth
That is a genuinely useful list, and it is also where we will stop, because those are the claims the evidence and regulators support.
Does magnesium glycinate help with sleep?
Magnesium glycinate is hugely popular in the sleep and relaxation conversation online, so it is worth being clear. Research on magnesium supplementation and sleep is mixed and still developing, and there is no authorised health claim for magnesium and sleep in the UK. Glycine itself has been explored in some small studies, but that evidence is early too. What magnesium can legitimately claim is its role in normal psychological function, the nervous system, and reducing tiredness and fatigue. If better evenings are your goal, magnesium may earn a place in your routine for those recognised reasons, but we will not promise it will send you to sleep, because the evidence does not let us.
Why choose the glycinate (bisglycinate) form of magnesium?
Magnesium comes in many supplemental forms, including oxide, citrate, malate and taurate. The glycinate form is often chosen for one practical reason: it is widely regarded as gentle on the stomach. Some forms of magnesium, particularly at higher doses, are known for a laxative effect. The chelated glycinate form is generally well tolerated, which matters, because the best supplement is one you can comfortably take every day.
On absorption, chelated forms like bisglycinate are often marketed as dramatically better absorbed, but head-to-head human data comparing forms is more limited than the marketing suggests. Tolerability, rather than a proven absorption advantage, is the more defensible reason this form is so popular.
Which foods are high in magnesium?
Magnesium is found in plenty of everyday foods: nuts (especially almonds and cashews), pumpkin and sunflower seeds, wholegrains, leafy greens like spinach, beans and lentils, and dark chocolate. A varied, balanced diet is the foundation, and no supplement replaces it.
That said, national diet surveys have repeatedly found that a meaningful share of UK adults, and teenage girls especially, fall short of recommended magnesium intakes, which is why a well-formulated supplement can be a sensible top-up.
How much magnesium do you need a day in the UK?
UK reference nutrient intakes for magnesium are 300mg a day for adult men and 270mg a day for adult women, which you would normally get across your whole diet. On food supplement labels, the Nutrient Reference Value (NRV) for magnesium is 375mg. For supplements, NHS guidance says taking 400mg or less of supplemental magnesium a day is unlikely to cause harm, and higher doses can cause digestive upset such as diarrhoea.
Magnesium glycinate FAQs
Is magnesium bisglycinate better than magnesium glycinate?
No. They are the same compound with two different names. Magnesium bisglycinate is the precise chemical name and magnesium glycinate is the common name.
What does "fully reacted" magnesium bisglycinate mean?
Fully reacted means all the magnesium in the ingredient is bound to glycine, rather than blended with other forms of magnesium such as magnesium oxide.
Is magnesium glycinate gentle on the stomach?
Magnesium glycinate is widely regarded as gentle on the stomach and is generally well tolerated. Some other forms of magnesium are more associated with a laxative effect, particularly at higher doses.
Can magnesium glycinate help you sleep?
There is no authorised health claim for magnesium and sleep in the UK, and research in this area is mixed. Magnesium does contribute to normal psychological function, normal functioning of the nervous system and the reduction of tiredness and fatigue.
How much magnesium glycinate should I take a day?
Follow the dose on the product label. NHS guidance says taking 400mg or less of supplemental magnesium a day is unlikely to cause harm. Speak to your GP or pharmacist if you take medication or have a health condition.
Who should not take magnesium supplements?
People with kidney problems should not take magnesium supplements without medical advice. If you are pregnant, breastfeeding, take regular medication (including certain antibiotics) or have a diagnosed health condition, speak to your GP or pharmacist first.
The bottom line
Glycinate or bisglycinate, it is the same compound: magnesium bound to two glycine molecules, in a form that is well tolerated and easy to take daily. That is why we named ours Magnesium Glycinate and list magnesium bisglycinate in the ingredients: the product is what it says, whichever name you searched for. Magnesium's recognised roles in reducing tiredness and fatigue, psychological function, muscle function and electrolyte balance make it a sensible addition to a daily routine. If you already take our Electrolytes+, magnesium is part of that formula too, and our complete guide to electrolytes covers how the minerals work together.
