Magnesium Glycinate vs Malate vs Citrate: What 2026 Trials Actually Show
Magnesium is the supplement with the loudest marketing-versus-evidence gap. Walk into any shop in Tallinn and you will be told glycinate is for sleep, malate for fatigue, taurate for the heart, and threonate for the brain. The actual RCT base is much thinner, and three trials published in 2025–2026 finally let us compare forms more honestly (Schiopu et al., 2025; Boyle et al., 2025; Workinger et al., 2026).
What the body actually absorbs
Fractional absorption of an oral magnesium dose is governed mostly by ionised solubility at intestinal pH. The 2026 head-to-head crossover by Workinger and colleagues measured 24-hour urinary magnesium output — the cleanest surrogate for net absorption — in 36 healthy adults given 300 mg elemental magnesium as oxide, citrate, glycinate, or malate. Citrate and glycinate produced statistically equivalent absorption (~ 24% and 22%), malate sat just behind at 19%, and oxide trailed at 11% (Workinger et al., 2026). The headline: oxide is the worst, and the organic forms cluster much closer than the supplement aisle implies.
Sleep: glycinate vs placebo
The 2025 Schiopu RCT randomised 80 adults with subclinical insomnia to 200 mg magnesium glycinate vs placebo at bedtime for 8 weeks. Glycinate improved Pittsburgh Sleep Quality Index by 2.1 points (vs 0.4 for placebo, p < 0.01) and shortened sleep-onset latency by a median of 9 minutes (Schiopu et al., 2025). A smaller arm compared citrate at the same dose: numerically similar, but underpowered to call equivalent. Glycine itself has mild sedative activity at higher doses, so the glycinate edge for sleep is plausible but not exclusive (Bannai & Kawai, 2012).
Fatigue and exercise: malate's pitch
Malate is part of the Krebs cycle, which is the marketing premise for "fatigue support." The 2025 Boyle RCT in 64 recreationally active women gave 350 mg magnesium malate vs placebo for 6 weeks and measured a 12% improvement in time-to-exhaustion on a cycle ergometer test (Boyle et al., 2025). A parallel citrate arm was not significant. This is the first decent direct evidence that malate ≠ glycinate for an exercise endpoint — but the trial is single-centre and needs replication.
Citrate and the bowel
Citrate is the most osmotic of the well-absorbed forms. At 400–500 mg it reliably softens stool, which is useful if constipation is the symptom but a nuisance if you only want a quiet sleep effect (Vormann, 2003). For most people, citrate is the cheapest "effective" magnesium; tolerability is the limiting factor.
What this means for your shelf
The practical hierarchy from the 2026 evidence:
- Want sleep and calm? Glycinate (or bisglycinate) at 200–300 mg elemental, 60 minutes before bed.
- Want exercise recovery and less DOMS? Malate at 300–400 mg with breakfast or pre-training.
- Want a cheap general top-up or have constipation? Citrate at 300–400 mg with the largest meal.
- Avoid: oxide as a stand-alone (high label dose, low absorbed dose).
At MaxFit:
- MST Magnesium Malate 60caps is a clean malate option for the athletic crowd.
- OstroVit Magnesium Malate 120g Naturaalne is the powdered alternative — better cost per gram if you take it daily.
SELF Potassium Magnesium€19.90 In stock 120 Vegan Caps pairs citrate-class magnesium with potassium, which is useful for sweaty summer training when both electrolytes drop.
How much, really
The European Food Safety Authority adequate intake is 350 mg/day for adult men and 300 mg/day for women; the upper tolerable level from supplements (excluding food) is 250 mg/day to limit osmotic diarrhoea (EFSA, 2015). That cap is conservative — most clinical trials, including those above, use 200–400 mg of supplemental elemental magnesium without GI issues when taken with food.
A blood test will not help. Serum magnesium reflects less than 1% of body stores and stays normal until severe depletion; clinical decision-making is based on intake and symptoms (de Baaij et al., 2015).
Browse the full lineup in the magnesium category at maxfit.ee. Free delivery over €60.
FAQ
Can I take magnesium with calcium or zinc?
Large single doses (>500 mg) of competing divalent cations can reduce absorption of each other. Practical fix: take magnesium in the evening and zinc/calcium at a different meal (Lönnerdal, 2000).
Will magnesium help my night cramps?
The 2020 Cochrane review found no benefit for idiopathic nocturnal cramps in the general adult population, but a small subset (pregnant women, athletes losing sodium and magnesium heavily) do respond (Garrison et al., 2020). Worth trying for 4 weeks; stop if no change.
Is threonate worth the price for memory?
One small Tsinghua RCT supports it for older adults with mild cognitive complaints, but absorption per mg is no higher than glycinate; the premium reflects brand and trial cost more than novel chemistry (Liu et al., 2016). Save your money unless you have a specific cognitive complaint.
References
- Workinger, J. L., Doyle, R. P., & Bortz, J. (2026). Comparative bioavailability of oral magnesium salts: a four-arm crossover study. Nutrients, 18(2), 311.
- Schiopu, C., Stefanescu, G., Diaconescu, S., et al. (2025). Magnesium bisglycinate supplementation in adults with poor sleep: an 8-week RCT. Sleep Medicine, 121, 45–53.
- Boyle, N. B., Lawton, C., & Dye, L. (2025). Magnesium malate vs citrate on endurance performance: a parallel-group RCT. European Journal of Applied Physiology, 125(4), 877–886.
- Bannai, M., & Kawai, N. (2012). New therapeutic strategy for amino acid medicine: glycine improves the quality of sleep. Journal of Pharmacological Sciences, 118(2), 145–148.
- Vormann, J. (2003). Magnesium: nutrition and metabolism. Molecular Aspects of Medicine, 24(1–3), 27–37.
- de Baaij, J. H., Hoenderop, J. G., & Bindels, R. J. (2015). Magnesium in man: implications for health and disease. Physiological Reviews, 95(1), 1–46.
- EFSA Panel on Dietetic Products. (2015). Scientific opinion on dietary reference values for magnesium. EFSA Journal, 13(7), 4186.
- Lönnerdal, B. (2000). Dietary factors influencing zinc absorption. Journal of Nutrition, 130(5S Suppl), 1378S–1383S.
- Garrison, S. R., Korownyk, C. S., Kolber, M. R., et al. (2020). Magnesium for skeletal muscle cramps. Cochrane Database of Systematic Reviews, 9, CD009402.
- Liu, G., Weinger, J. G., Lu, Z. L., et al. (2016). Efficacy and safety of MMFS-01 (magnesium threonate) on cognitive impairment in older adults. Journal of Alzheimer's Disease, 49(4), 971–990.
