Magnesium Glycinate vs Citrate vs Malate: Which Form Is Best?
Not all magnesium is the same. We break down the 3 most popular forms: glycinate for sleep, citrate for digestion, malate for energy, with dosing, absorption, and what to look for on the label.
Why magnesium form matters more than dose
Magnesium is the 4th most abundant mineral in the human body and a cofactor in 300+ enzymatic reactions. Yet 48% of Americans don't get enough from diet alone. Supplementing seems simple, until you see 12+ forms of magnesium on the shelf, each with different absorption rates, benefits, and side effects.
What follows comes from the published clinical literature on each form, the certifications the brands actually hold, and what buyers consistently report. Here is what that says.
The RDA for magnesium is 400-420mg for men, 310-320mg for women. Most supplements provide 200-400mg per serving, don't exceed 350mg from supplements alone (upper limit from the NIH).
Magnesium Glycinate, Best for sleep + anxiety
Magnesium glycinate is magnesium bound to glycine, an inhibitory neurotransmitter that promotes relaxation. Glycine on its own has been shown to improve sleep quality in clinical studies, and that is why this is the form people take at night rather than in the morning.
Glycinate is a chelated form, which is why it is the gentlest of the three on the stomach: it does not pull water into the gut the way citrate does, so there is no laxative effect at normal doses. If you are taking magnesium for sleep, anxiety, or general relaxation, glycinate is the clear choice.
- ▸Best for: Sleep, anxiety, muscle relaxation
- ▸Absorption: chelated, and among the best-absorbed forms on the shelf
- ▸GI tolerance: Excellent (no laxative effect)
- ▸Dose: 200-400mg elemental magnesium, taken 30-60 min before bed
- ▸Look for: "Magnesium bisglycinate" or "magnesium glycinate" on label
Magnesium Citrate, Best for digestion + constipation
Magnesium citrate is magnesium bound to citric acid. It is the form doctors most often recommend for constipation, because it draws water into the intestines. That osmotic effect is not a side effect here. It is the mechanism, and it works within hours.
The downside is that same mechanism. Push the dose up and the loose stools follow, reliably. Citrate is not ideal for daily sleep use: the laxative effect defeats the purpose. Use it occasionally for constipation, not as a daily supplement.
- ▸Best for: Constipation relief, occasional use
- ▸Absorption: good, though below the chelated forms
- ▸GI tolerance: Laxative effect at >300mg (can be desired or unwanted)
- ▸Dose: 200-300mg for daily use; up to 600mg for constipation
- ▸Look for: "Magnesium citrate", avoid if you have IBS-D
Magnesium Malate, Best for energy + muscle pain
Magnesium malate is magnesium bound to malic acid, which feeds the Krebs cycle (ATP production). In theory that should support daytime energy. In practice the evidence is thin, and anyone who tells you it feels like caffeine is selling you something.
You will read everywhere that malate is the form for fibromyalgia and chronic muscle pain. We looked for the research behind that, and it is not there. Two trials have tested magnesium with malic acid in fibromyalgia. Abraham and Flechas (1992) was open-label, meaning everyone knew what they were taking, and it reported an improvement. Russell et al. (Journal of Rheumatology, 1995) ran the randomised, double-blind, placebo-controlled version, and found no significant improvement over placebo. A 2021 review of the whole literature (Boulis, Boulis and Clauw) concludes that magnesium's role in fibromyalgia is not certain, because no properly blinded trial has ever tested magnesium on its own for it.
So we are not going to tell you to buy malate for pain. The one trial that was designed to detect an effect did not detect one. If you want magnesium for muscle cramps or general repletion, malate is a perfectly good, well-absorbed form and it is often cheaper than glycinate. Buy it for that. Do not buy it for a claim that the evidence does not carry.
- ▸Best for: Daytime energy, muscle pain, fibromyalgia support
- ▸Absorption: good, and better tolerated than citrate at the same dose
- ▸GI tolerance: Good (mild laxative at high doses)
- ▸Dose: 200-400mg elemental magnesium, taken in the morning
- ▸Look for: "Magnesium malate", take with food for best absorption
Which form should you choose?
For sleep + anxiety: Magnesium glycinate, 300mg, 30-60 min before bed. This is our #1 recommendation for most people.
For constipation: Magnesium citrate, 300mg, as needed. Don't use daily unless your doctor recommends it.
For energy + muscle pain: Magnesium malate, 300mg, with breakfast. Good for athletes and office workers with tension headaches.
AVOID: magnesium oxide, whose absorption sits in the low single digits in published studies, which makes it close to useless. Also avoid magnesium sulfate (Epsom salts): topical and bath use only, not oral.