Magnesium Glycinate vs Citrate: Which Should You Take?
Last updated: 2026-08-31 · by Sun Supplements
Glycinate and citrate are the two most popular UK magnesium forms. Both are well-absorbed; they differ in calming effect, GI tolerability, and best use cases. This head-to-head comparison helps you pick the right one for your goal.
Quick verdict
| Magnesium Glycinate | Magnesium Citrate | |
|---|---|---|
| Best for | Sleep, anxiety, daily use | Constipation, general use |
| Elemental Mg | ~14% | ~16% |
| Absorption | High, well-tolerated | High, mild laxative effect |
| Calming effect | Strong (GABA modulation) | Mild |
| Stomach | Gentle, no laxative effect | Can cause loose stools at higher doses |
| Price | Slightly higher per elemental mg | Slightly lower |
Pick glycinate for sleep, anxiety, muscle relaxation, and daily long-term use.
Pick citrate if you also want a mild constipation-relief effect, or for general magnesium support where calming isn't the priority.
Absorption compared
Both forms are well-absorbed — significantly better than cheap magnesium oxide. Studies show similar bioavailability between glycinate and citrate when measured by urinary excretion. However, glycinate has a slight edge in real-world use because:
- It doesn't compete with other minerals for transport (citrate can bind with calcium in the gut).
- It doesn't cause loose stools, which means you can take a full therapeutic dose without GI upset.
Citrate, on the other hand, is slightly more concentrated by elemental percentage (~16% vs ~14%), so you get marginally more magnesium per gram of compound.
Effects on the body
Glycinate — calming, sleep-supportive
Magnesium glycinate is magnesium bound to the amino acid glycine. The glycine itself is calming — it's an inhibitory neurotransmitter and supports sleep quality. The combination of magnesium's GABA-modulating effects plus glycine's neurotransmitter activity makes glycinate the form of choice for sleep and anxiety.
Citrate — versatile, mild bowel effect
Magnesium citrate is magnesium bound to citric acid. It's well-absorbed and works for general magnesium repletion. At higher doses (typically >300 mg elemental), it has a mild osmotic laxative effect — which can be useful if you tend toward constipation, but problematic if you have loose stools already.
Which to choose
- Sleep / insomnia: Glycinate (clear winner)
- Anxiety / stress: Glycinate
- Muscle cramps: Either — glycinate has the edge for sleep-related cramping; citrate is fine for daytime use
- Constipation + magnesium: Citrate
- Exercise recovery: Either; both work
- Pregnancy: Glycinate (better tolerated)
- Children: Glycinate (gentler on stomach)
- Migraine prevention: Either at 400-600 mg/day
Top UK products for each
Glycinate
- NOW Foods Magnesium Glycinate 400 mg — best value
- Solaray Magnesium Glycinate 400 mg — vegan
- Swanson Magnesium Glycinate Powder — bulk powder, easy to dose
Citrate
- Solgar Magnesium Citrate — premium heritage
- NOW Foods Magnesium Citrate 200 mg — value tier
FAQ
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