Short answer: magnesium glycinate and magnesium citrate are both organic, well-absorbed forms of magnesium, and both beat magnesium oxide on absorption. Citrate has the most head-to-head absorption data and a stronger effect on the gut. Glycinate is bound to the amino acid glycine and is the go-to evening form for people building a calm, sleep-friendly routine.
Why the form matters
About two in three US adults get less magnesium from food than recommended (study). When you supplement, the form changes how much your body takes in. In a review of US commercial products, magnesium oxide was among the most poorly absorbed, while organic forms did better (study).
Magnesium citrate: the absorption benchmark
- In a 60-day randomized, double-blind trial of 46 healthy adults taking 300 mg of magnesium a day, citrate and an amino-acid chelate were both absorbed better than oxide, and citrate gave the highest blood magnesium levels (study).
- An earlier study found magnesium citrate dissolved far better than oxide and was linked to a much bigger rise in urinary magnesium, a marker of absorption (study).
- Citrate draws water into the gut, which is why it's also the form in many over-the-counter laxatives. Some people like that effect; others find it too much at higher doses.
Magnesium glycinate: the evening favorite
- Glycinate (diglycinate) is a chelate, meaning magnesium is bound to glycine. In a small crossover trial, part of it was absorbed intact through an amino-acid pathway, and it was better tolerated than magnesium oxide (study).
- Magnesium itself has been linked to lower anxiety scores in people prone to anxiety (study) and to falling asleep about 17 minutes faster in older adults (study).
- Those studies used various forms of magnesium, so the benefit comes from the magnesium. Glycinate is simply an easy, well-absorbed way to take it at night.
Quick comparison
| Glycinate | Citrate | |
|---|---|---|
| Absorption vs oxide | Better | Better (most data) |
| Effect on the gut | Gentle | Draws in water, can loosen stools |
| Best fit | Evening wind-down, calm and sleep routines | Daytime top-up, people who want regularity support |
How much?
For adults, the upper limit for magnesium from supplements is 350 mg a day; food magnesium doesn't count toward it. Add up every product you take. Our Magnesium Glycinate gives you 275 mg per 3-capsule serving.
The bottom line
Both forms are a big step up from oxide. Pick citrate if you want the form with the most absorption data or a little help with regularity. Pick glycinate if you want a gentle evening habit for calm and sleep. If that's you, try our Magnesium Glycinate, three capsules about an hour before bed.
