Magnesium threonate is one of the most heavily marketed sleep supplements of the last two years. The pitch is that this form crosses into the brain better than other magnesium salts, so it should help you fall asleep faster and wake up less. If you are deciding whether it earns a place on your shelf, the useful question is not "is there a study" but "what does the whole evidence base look like, and how much of it is recent?"
ProtocolEngine grades magnesium threonate a C. That grade comes from 5 papers carrying 22 extracted claims, scored across six factors (study quality, replication, sample size, consistency, effect size, recency). A C means the evidence is suggestive but limited: small studies, few replications, or both. It does not mean the supplement does nothing. It means nobody has yet run the studies that would let anyone say so with confidence.
Here is the experiment we ran on our own database. Keep only research published in the last 3 years and re-grade. Four of the five papers drop out. What remains is a single paper with a single claim, and the grade falls from C to E, which is our lowest tier: insufficient evidence.
Read that carefully, because it cuts both ways. The recent-evidence filter does not show that magnesium threonate fails. It shows that almost everything we know about it comes from a handful of older, small studies, and that the recent wave of marketing has not been matched by a recent wave of research. A supplement having a moment on social media is not the same thing as a supplement having a moment in the literature.
Sleep responds strongly to things that cost nothing. A consistent wake time, morning light, and a cool dark room have deeper evidence bases than most sleep supplements, and they are where we would start. If you want to try magnesium anyway, know which question research has actually asked (whether magnesium intake relates to normal nervous-system function and fatigue, the properties regulators actually recognize) and which is not (whether the threonate form specifically improves sleep outcomes, or is worth its price premium over cheaper, better-studied forms).
We re-grade the entire database daily as new research lands. 400+ papers came in over the last 7 days alone. If someone finally runs the large recent trial magnesium threonate needs, its grade will move, and the page will say so the same day.
If sleep is the outcome you care about, the sleep protocol ranks every graded intervention (habits first, then diet, then supplements) with the underlying trials one click away. The fastest way to a plan matched to your situation is the protocol quiz. How the six-factor grading works is documented on the methodology page.
ProtocolEngine provides general health information based on published research. This is not medical advice. Consult a healthcare professional before starting any supplement or health protocol.