Magnesium glycinate binds magnesium to glycine for good absorption and gastrointestinal tolerability (Blancquaert et al., 2019). Some use it to promote restful nights.
Key Research on Glycinate
A 2025 double-blind trial in 155 adults with poor sleep found modest improvements in Insomnia Severity Index scores after four weeks at 250 mg elemental magnesium (Schmid et al., 2025). Organic forms like glycinate generally absorb well with fewer side effects (Blancquaert et al., 2019).
Misconceptions vs. Reality
It’s sometimes viewed as highly effective for all. Evidence supports modest benefits for mild issues, but larger trials with objective measures are still needed (Arab et al., 2023).
Quality Considerations
Select third-party tested options to avoid contaminants or lower-quality substitutions.
Practical Implications
It may modestly support sleep for those with low dietary intake (Schmid et al., 2025). Typical doses range from 200–300 mg elemental magnesium.
Keep reading → Part 3: Magnesium L-Threonate for Sleep and Brain Health
References
Arab, A., Rafie, N., Amani, R., & Shirani, F. (2023). The role of magnesium in sleep health: a systematic review of available literature. Biological Trace Element Research, 201(1), 121–128. https://doi.org/10.1007/s12011-022-03162-1
Blancquaert, L., Vervaet, C., & Derave, W. (2019). Predicting and testing bioavailability of magnesium supplements. Nutrients, 11(7), 1663. https://doi.org/10.3390/nu11071663
Hausenblas, H. A., Lynch, T., Hooper, S., Shrestha, A., Rosendale, D., & Gu, J. (2024). Magnesium-L-threonate improves sleep quality and daytime functioning in adults with self-reported sleep problems: A randomized controlled trial. Sleep Medicine: X, 8, 100121. https://doi.org/10.1016/j.sleepx.2024.100121
Mah, J., & Pitre, T. (2021). Oral magnesium supplementation for insomnia in older adults: a systematic review & meta-analysis. BMC Complementary Medicine and Therapies, 21(1), 125. https://doi.org/10.1186/s12906-021-03297-z
Schmid, C., et al. (2025). Magnesium bisglycinate supplementation in healthy adults reporting poor sleep: A randomized, placebo-controlled trial. Nature and Science of Sleep, 17, 2027–2040. https://doi.org/10.2147/NSS.S524348
Slutsky, I., et al. (2010). Enhancement of learning and memory by elevating brain magnesium. Neuron, 65(2), 165–177. https://doi.org/10.1016/j.neuron.2009.12.026
Uysal, N., et al. (2019). Timeline (bioavailability) of magnesium compounds in hours: Which magnesium compound works best? Biological Trace Element Research, 187(1), 128–136. https://doi.org/10.1007/s12011-018-1351-9