Magnesium glycinate is magnesium bound to the amino acid glycine. It is popular because it is well absorbed and gentle on the stomach compared with cheaper forms such as magnesium oxide. Evidence suggests it may help with sleep quality and muscle relaxation, though the research is still modest — promising, not proven.
Key takeaways
- A gentle, well-absorbed form of magnesium.
- Commonly used in the range of 200–350 mg of elemental magnesium per day (check the label — “elemental” is what counts).
- Evening use is popular for sleep.
- Side effects are uncommon and usually limited to loose stools at higher doses.
Who this is for
People with poor sleep or muscle tension, and anyone who gets digestive upset from other magnesium forms.
Who should be cautious: people with kidney disease, very low blood pressure, or those taking certain antibiotics or blood pressure medicines — speak to your GP or pharmacist first.
What the evidence says (and its limits)
Sleep: small trials suggest modest improvements in sleep quality; it is not a sedative.
Muscle cramps: evidence is mixed.
Stress and anxiety: early research only — “may help” is the honest phrase.
Glycinate vs citrate vs oxide
- Glycinate: gentle on digestion, good absorption, pricier.
- Citrate: decent absorption, can loosen stools.
- Oxide: cheap, poorly absorbed, mostly useful as a laxative.
Dosage and timing
Typical supplemental range is 200–350 mg of elemental magnesium daily; start low and build up. Taking it 30–60 minutes before bed is the common routine for sleep. Take it apart from thyroid medication and some antibiotics — ask your pharmacist about timing.
Side effects and safety
Loose stools or diarrhoea at higher doses; occasional nausea; mild drowsiness. Do not exceed the label dose or your clinician’s advice — very high doses can be dangerous.
Frequently asked questions
How long until it works? Give it days to a few weeks for sleep effects.
Can I take it every night? Generally yes at sensible doses.
Does it interact with medication? Yes — check with a pharmacist.
Your next step
Read our guide to the best supplements for sleep, graded honestly by the evidence.
Related reading: our complete beginner’s guide to supplements, and how to read a supplement label like a pro.
Written by the Nourish & Glow editorial team · Published 21 September 2026 · Last reviewed 21 September 2026
General information only — not medical advice. If you have a health condition, take medication, or are pregnant or breastfeeding, speak to a qualified professional before using supplements.
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