When it comes to magnesium, absorption (also called bioavailability) depends on both the form of magnesium and your individual digestive health. Here’s a breakdown of the most common supplemental forms and how well they’re absorbed:
Best-absorbed forms (high bioavailability)
- Magnesium glycinate (bisglycinate)
- Chelated form (bound to the amino acid glycine).
- Very well absorbed, gentle on the stomach, and less likely to cause diarrhea.
- Great for people who need to take higher doses or who have sensitive digestion.
- Often recommended for anxiety, sleep, and muscle relaxation.
- Magnesium malate
- Magnesium bound to malic acid.
- Well absorbed and may help with muscle energy production.
- Sometimes chosen for fatigue, fibromyalgia, or muscle pain.
- Magnesium citrate
- Magnesium bound to citric acid.
- Well absorbed, but can have a mild laxative effect in higher doses.
- Good choice for those with mild constipation.
- Magnesium taurate
- Bound to the amino acid taurine.
- Well absorbed and may support cardiovascular health.
Moderate absorption forms
- Magnesium chloride
- Decent absorption, sometimes used topically (lotions, sprays, baths).
- Can be helpful for people with digestive issues.
- Magnesium lactate
- Well absorbed and gentle on the gut, but less commonly sold as a supplement.
Poorly absorbed forms (cheap but not great)
- Magnesium oxide
- Very common and inexpensive.
- Poor absorption (~4%).
- More likely to cause diarrhea.
- Sometimes used for constipation rather than as a magnesium replenisher.
✅ Best all-around daily choice for absorption and tolerability:
Magnesium glycinate (bisglycinate)
👉 If your main goals are energy and muscle support, magnesium malate is great.
👉 If your main goals are constipation relief, magnesium citrate works well.
