Magnesium Glycinate vs Citrate: Which Should You Take?

Magnesium glycinate and magnesium citrate are the two most popular forms of magnesium supplement, and they’re often recommended for different reasons. This comparison looks at how they differ in absorption, how much magnesium each capsule actually contains, side effects, cost and the claims made for sleep and anxiety.

For all the other forms, including oxide, malate and threonate, see our full guide to types of magnesium. To get more magnesium from food, see magnesium-rich foods.

Side-by-side comparison

Percentages are calculated from each compound’s chemical formula and vary between products. Highlighted cells show the advantage for that feature.

Absorption

The NIH Office of Dietary Supplements notes that forms of magnesium that dissolve well in liquid, including citrate, are absorbed better than poorly soluble forms such as magnesium oxide. Magnesium citrate is one of the most studied forms, and several small studies found it raised blood or urine magnesium more than oxide.

Magnesium glycinate (often labeled bisglycinate) is also well absorbed, but there are fewer direct studies of it, and no good trial shows it’s absorbed meaningfully better than citrate. For most people, the difference in absorption between the two is small. What matters more is the dose and whether the form agrees with your stomach.

Winner: a tie, with more evidence behind citrate.

How much magnesium you actually get

Both compounds are mostly the partner molecule, so each capsule contains much less magnesium than its total weight. For example, 1,000 mg of magnesium glycinate provides only about 140 mg of actual (elemental) magnesium, and 1,000 mg of magnesium citrate provides about 160 mg.

On a US Supplement Facts panel, the number listed next to magnesium is already the elemental amount. “Magnesium (as magnesium glycinate) 200 mg” means 200 mg of magnesium. Always compare products using that figure, not the compound weight sometimes printed on the front of the bottle. Our guide on how to read a supplement label explains this in more detail.

Winner: a tie; check the elemental dose on the label.

Side effects and the laxative effect

This is the clearest difference. Magnesium citrate draws water into the bowel, which gives it a mild laxative effect, especially at doses above about 300 mg. That’s useful if you’re prone to constipation, and unwelcome if you’re not. Liquid magnesium citrate sold in pharmacies is a strong laxative used before medical procedures, not a daily supplement.

Magnesium glycinate is much less likely to cause loose stools or stomach upset, which is why it’s often recommended for people with sensitive digestion or who need to take magnesium every day. Both can still cause diarrhea, nausea or cramps at high doses.

Winner: glycinate for a gentle daily supplement; citrate if you want the laxative effect.

Sleep, anxiety and other claims

Magnesium glycinate is heavily marketed for sleep and anxiety, partly because glycine itself has mild calming effects. However, no good trials show glycinate works better than citrate, or than any other form, for either.

The evidence for magnesium in general is limited. A 2021 review of three small trials in older adults found people taking magnesium fell asleep about 17 minutes faster on average, but the evidence was judged low quality. If you want to try magnesium for sleep, glycinate is a reasonable choice because it’s gentle, but expect a modest effect at best. Our guide to herbal teas for sleep covers other bedtime options.

For migraine prevention, where magnesium has better evidence, studies mostly used magnesium oxide or citrate at doses above the upper limit, so talk to your doctor first.

Winner: no proven difference.

Cost

Magnesium citrate is usually cheaper per 100 mg of magnesium than glycinate, and it’s widely available in capsules and powders. Glycinate costs more partly because of the manufacturing process and partly because of its marketing as a premium form. Some cheaper “glycinate” products are buffered with magnesium oxide to raise the magnesium content; look for “fully reacted” or “100% chelated” if you want pure glycinate.

Winner: citrate.

Which should you choose?

Choose magnesium glycinate if you:

• Have a sensitive stomach or got loose stools from other forms.
• Want a supplement to take every day, long term.
• Want to try magnesium at bedtime and prefer the gentlest option.

Choose magnesium citrate if you:

• Tend toward constipation and welcome a mild laxative effect.
• Want the best-studied well-absorbed form.
• Want the lower-cost option.

Before either, check your diet. Pumpkin seeds, almonds, spinach, black beans and whole grains can cover most of your daily magnesium, and food magnesium doesn’t count toward the supplement upper limit.

Safety and interactions

See also our medical disclaimer.

Other forms worth knowing

Glycinate and citrate are the two most popular choices, but you’ll see several other forms on the shelf. Here’s how they compare:

• Magnesium oxide: cheap and very high in magnesium by weight (about 60 percent), but poorly absorbed and the most likely to cause diarrhea. It’s used as a laxative and antacid, and in many migraine studies.
• Magnesium chloride and lactate: both dissolve easily and are reasonably well absorbed, similar to citrate. Lactate tends to be gentle on the stomach.
• Magnesium malate: marketed for energy and muscle pain, with little evidence for those specific claims.
• Magnesium L-threonate: marketed for memory because animal studies suggest it raises brain magnesium. It’s expensive and contains only about 8 percent magnesium, so you need several capsules for a modest dose.
• Blends: some products combine glycinate, citrate and other forms. These can work well, as long as the label lists the total elemental magnesium.

Our full guide to types of magnesium includes a table comparing nine forms by magnesium content, absorption and laxative effect.

How to take magnesium

• Start low: begin with 100 to 200 mg of elemental magnesium a day and see how your stomach reacts before increasing.
• Take it with food: this reduces nausea and stomach upset with either form.
• Split larger doses: two smaller doses are often better tolerated than one large dose and may be absorbed better.
• Pick a time you’ll remember: timing doesn’t matter much. Many people take magnesium in the evening, especially glycinate.
• Give it time: for constipation, citrate can work within hours. For raising low intake or migraine prevention, it may take several weeks of regular use.
• Count everything: add up magnesium from your multivitamin, antacids, laxatives and any other supplements to stay within the 350 mg limit.

Magnesium from food doesn’t count toward that limit. A handful of pumpkin seeds provides about 168 mg, and an ounce of almonds about 77 mg. See our guide to pumpkin seeds for one of the richest food sources.

Related on Pure Nutrition Facts: our ashwagandha guide.

Magnesium glycinate vs citrate FAQ