Supplements
Magnesium-L-threonate improved sleep in a placebo-controlled trial
At a glance
| Study type | Randomized controlled trial |
|---|---|
| Year | 2024 |
| Journal | Sleep Medicine: X |
| Sample | n = 80 |
| Population | General adult |
Background
An 80-person, double-blind RCT of 1 g/day magnesium-L-threonate vs placebo for 21 days showed improvements in subjective sleep quality, total sleep time, deep sleep, sleep efficiency, and daytime functioning.
Which magnesium form is best for sleep — and why does that matter?
Trials have studied citrate, oxide, glycinate (bisglycinate), and L-threonate. Threonate is the only form shown to meaningfully cross the blood-brain barrier in animal work, which is the proposed mechanism for sleep-architecture effects (rather than just gut/muscle effects). The Hausenblas 2024 RCT is the strongest current human trial of L-threonate specifically.
What did the trial actually measure?
80 adults aged 35–55 with self-reported sleep problems, randomized to 1 g/day magnesium-L-threonate or placebo for 21 days. Primary outcomes were subjective sleep quality (PSQI/ISI-style scales) and daytime functioning; objective measures (total sleep time, deep sleep, efficiency) were secondary.
Is magnesium safe in pregnancy?
Magnesium itself is well-tolerated in pregnancy at typical supplemental doses, but the L-threonate form has not been specifically tested in pregnant participants. Discuss any new supplement with your clinician — Solas surfaces this caveat directly on the recommendation.
How does this translate into a recommendation?
For users not currently pregnant or breastfeeding, Solas may suggest 1 g/day magnesium-L-threonate, taken 30–60 minutes before bed, as a 21-day trial — and asks you to log subjective sleep quality before and after so the signal is testable on your own data.
Source
Hausenblas HA, 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.
DOI: 10.1016/j.sleepx.2024.100121
Read the original paper →
Solas does not own or distribute the underlying paper. Follow the link to the publisher for the full text. See our methodology.