Magnesium L‑threonate improves sleep quality

A randomized, placebo-controlled trial published in *Sleep Medicine: X* found that magnesium L-threonate improved both measured sleep metrics and self-reported sleep quality in adults with sleep problems. The study enrolled 80 adults ages 35 to 55 and compared 1 gram per day of magnesium L-threonate with placebo over 21 days. AJMC reported the findings in an article published September 18, 2024, citing gains in deep sleep, REM sleep and daytime functioning. ### Who was studied, and what did they take? Heather A. Hausenblas of Jacksonville University and colleagues studied 80 adults ages 35 to 55 who reported sleep problems. Participants were assigned in a randomized, double-blind, placebo-controlled, parallel-arm trial to receive either 1 gram per day of magnesium L-threonate or a daily placebo for 21 days. (ajmc.com) The paper said sleep and daily behavior were tracked with standardized questionnaires and with an Oura ring wearable device. The questionnaire battery included the Insomnia Severity Index, Leeds Sleep Evaluation Questionnaire and Restorative Sleep Questionnaire, while mood, energy and productivity were also logged through a daily diary and the Profile of Mood States questionnaire. (magtein.com) ### What changed in the objective sleep data? The study reported statistically significant improvements versus placebo in several Oura-based measures, including deep sleep score, REM sleep score and light sleep time. The magnesium L-threonate group also showed gains in activity and readiness measures, including activity score, daily movement score, readiness score, activity balance and sleep balance, according to the abstract. (magtein.com) AJMC said the trial stood out because it measured both objective and subjective sleep outcomes rather than relying only on self-reports. The article said the supplement led to benefits in “both objective and subjective sleep metrics,” based on the placebo-controlled study. ### What did participants report about how they felt? (magtein.com) The abstract said participants taking magnesium L-threonate reported significant improvements versus placebo in behavior upon awakening, energy, daytime productivity, grouchiness, mood and mental alertness. The authors summarized those findings as better sleep quality, especially during deep and REM sleep stages, along with better daytime functioning. (ajmc.com) AJMC reported that the intervention was linked not only to sleep changes but also to improved daytime functioning. That article cited the study as evidence that this magnesium salt may show a clearer benefit than earlier magnesium research, which the authors said had produced mixed clinical evidence. (magtein.com) ### Why did the researchers focus on this magnesium salt? The authors wrote that prior magnesium evidence for sleep had been inconsistent and that one possible reason was the form of magnesium used. They described magnesium L-threonate as a form with stronger brain bioavailability in animal studies and said that property led them to test whether it could perform better as a sleep aid. (ajmc.com) AJMC said the researchers contrasted the new findings with earlier work, including a meta-analysis of three randomized trials that found only a modest, statistically insignificant improvement in sleep time among older adults taking magnesium. The article quoted the earlier analysis as saying the evidence base was not strong enough for physicians to make well-informed recommendations on oral magnesium use. (ajmc.com) ### What can be said about safety and what comes next? The abstract said magnesium L-threonate was safe and well tolerated during the 21-day study period. The paper’s conclusion said the findings suggest a role in clinical practice as an adjunct approach for healthy individuals experiencing sleeplessness or related daytime effects, though that statement came from the study authors. (ajmc.com) The next step for readers is the full paper in *Sleep Medicine: X*, titled “Magnesium-L-threonate improves sleep quality and daytime functioning in adults with self-reported sleep problems: A randomized controlled trial,” by Hausenblas, Tarah Lynch, Stephanie Hooper, Aahana Shrestha, Doug Rosendale and Jennifer Gu. (magtein.com)