Guide
Types of magnesium compared: glycinate, citrate, oxide, malate, threonate and more
Elemental magnesium ranges from about 6% to 60% by weight depending on the form. Here's every common form compared on that number, typical use, and what head-to-head human evidence actually exists.
There is no single "best" form of magnesium: no well-powered human trial has shown one common form is reliably better absorbed than the others in healthy adults, and glycinate in particular has never beaten citrate head-to-head. What actually differs between forms is elemental magnesium per gram, what each form is typically sold for, and side-effect profile. This page compares them; the linked pages go deeper on each pair.
Elemental magnesium, form by form
"Elemental" is the weight of magnesium itself, separate from whatever it's bound to. It's the number that determines how much magnesium you're actually taking, and it varies a lot by form — from about 6% to 60% of the compound's weight.
| Form | Formula | Molar mass | Elemental Mg by weight |
|---|---|---|---|
| Oxide | MgO | 40.3 g/mol | ~60% |
| Chloride | MgCl2 (anhydrous) or ·6H2O | 95–203 g/mol | 12–26% |
| Sulfate | MgSO4 (anhydrous) or ·7H2O (Epsom salt) | 120–246 g/mol | 10–20% |
| Citrate | Mg3(C6H5O7)2 | 451.1 g/mol | ~16% |
| Malate | C4H4MgO5 | 156.4 g/mol | ~16% |
| Lactate | C6H10MgO6 | 202.5 g/mol | ~12% |
| Glycinate (bisglycinate) | C4H8MgN2O4 | 172.4 g/mol | 11–14% |
| Taurate | C4H12MgN2O6S2 | 272.6 g/mol | ~9% |
| Gluconate | C12H22MgO14 (or dihydrate) | 415–451 g/mol | 5–6% |
| Orotate | C10H6MgN4O8 | 334.5 g/mol | ~7% |
| L-threonate | C8H14MgO10 | 294.5 g/mol | ~8% |
Our own label is magnesium glycinate at 11% (275 mg elemental from 2,500 mg of compound) — under the ~14% ceiling pure glycinate can reach, which is consistent with the label being what it says it is.
What each form is typically sold for
| Form | Typically sold for | Watch out for |
|---|---|---|
| Glycinate | General supplementation, marketed on sleep and gentleness | Neither the sleep nor the gentleness claim is well supported at typical doses |
| Citrate | General supplementation; concentrated liquid citrate is also sold as an OTC saline laxative at much higher doses | The laxative-dose product and a daily supplement capsule are not interchangeable |
| Oxide | Cheap, high-elemental-% capsules and antacid/laxative products | Lowest measured absorption of the forms tested head-to-head |
| Malate | Marketed toward exercise and general energy | Little dedicated human trial evidence for malate specifically, apart from its magnesium content |
| L-threonate | Marketed on animal data showing it raises brain magnesium | Human trials are small, short and funded by the ingredient's patent holder |
| Taurate | Marketed toward cardiovascular and calm-focus use, paired with taurine's own reputation | Almost no dedicated human trials of the taurate salt itself |
| Chloride / gluconate / sulfate / orotate | Topical products (chloride), gentle low-dose liquids (gluconate), laxative prep (sulfate), niche cardiac-research products (orotate) | Low elemental % (gluconate, orotate) means a lot of capsule for little magnesium |
What head-to-head human evidence actually exists
Very little, and what exists doesn't favor glycinate. A 60-day randomized trial in 46 healthy adults compared citrate, an amino-acid chelate and oxide at a matched 300 mg elemental dose: citrate produced the highest blood magnesium, both acutely and after 60 days, while the chelate did not outperform it and oxide didn't differ from placebo. A 2024 crossover study in 40 healthy adults found plasma magnesium rose after citrate and oxide but not after magnesium bisglycinate — a result that runs against the glycinate-is-better story, though it was funded by a competing ingredient maker and should be read with that in mind. The only human trial comparing glycinate to oxide directly gave a single 100 mg dose to 12 patients who'd had part of their small intestine removed; the whole-group result was a tie (23.5% vs 22.8% absorbed), and the often-cited glycinate advantage came from a post hoc subgroup of the four people who absorbed oxide worst. A 2017 review of the wider absorption literature concludes plainly that the type of magnesium salt matters less than is commonly assumed.
Put together: no form has a solid absorption advantage in healthy adults, and where a comparison exists, glycinate has not won it.
Compare specific pairs
- Magnesium glycinate vs citrate
- Magnesium glycinate vs oxide
- Magnesium glycinate vs malate
- Magnesium glycinate vs L-threonate
- Magnesium glycinate vs taurate
- Magnesium glycinate vs chloride, gluconate, sulfate and orotate
- Magnesium vs magnesium glycinate (plain magnesium mineral vs the chelated form)
Questions people ask
Which magnesium glycinate is best?
Look for the elemental magnesium figure and check it against the compound weight: it should land at or under roughly 14% for a product that's genuinely glycinate alone. Beyond that, price per 100 mg of elemental magnesium is the practical way to compare products, since no absorption advantage between well-formulated products has been demonstrated.
Is magnesium glycinate better absorbed than other forms of magnesium?
Not on the evidence. It's a reasonably well-tolerated, moderately concentrated form, but no trial shows it absorbed better than citrate or oxide, and citrate has actually outperformed an amino-acid chelate in the one trial that compared them directly in healthy adults.
Which magnesium glycinate is best for sleep?
None has a strong evidence base for sleep. The broadest recent systematic review of oral magnesium and sleep, across 12 trials, rated the certainty of evidence low to very low and concluded it does not support magnesium as a routine sleep treatment. See our full review of that literature for the detail.
Which magnesium glycinate or citrate should I take?
If you want the highest elemental percentage from a well-evidenced organic form, citrate is the stronger absorption case on the current data. If your priority is a lower-dose daily capsule and citrate's mild stool-loosening effect is unwelcome, glycinate is a reasonable alternative — but on the evidence, "gentler" is an assumption, not a demonstrated difference.
Does the form of magnesium affect whether it's independently tested?
No. Independent lab testing is a property of the brand and the batch, not the chemical form. Check a product's own certificate of analysis rather than assuming glycinate, citrate or any other form is inherently more or less tested than another.
What is the difference between magnesium and magnesium glycinate?
"Magnesium" on its own usually means a plain inorganic salt like oxide or an unspecified blend; "magnesium glycinate" specifies the chelate bound to glycine. See magnesium vs magnesium glycinate for the full comparison.
Sources
- Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study In 46 healthy adults taking 300 mg a day for 60 days, citrate raised blood magnesium most; an amino-acid chelate did not beat it.
- Comparative Clinical Study on Magnesium Absorption and Side Effects After Oral Intake of Microencapsulated Magnesium (MAGSHAPE(TM) Microcapsules) Versus Other Magnesium Sources In 40 healthy adults given one dose, blood magnesium rose after citrate and oxide but not significantly after bisglycinate.
- Bioavailability of magnesium diglycinate vs magnesium oxide in patients with ileal resection In 12 people after bowel surgery, one 100 mg dose of glycinate was absorbed about the same as oxide overall.
- Intestinal Absorption and Factors Influencing Bioavailability of Magnesium-An Update A 2017 review of magnesium absorption research concluded the type of magnesium salt matters less than is often claimed — the evidence for one form being reliably better absorbed than another is inconsistent.
*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.
