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Short Summary
Main recommendation: Dr. Andrew Huberman and Dr. Rhonda Patrick favor magnesium bisglycinate (also called magnesium glycinate) taken a couple of hours before bed for sleep, with magnesium L-threonate discussed as a newer option for possible cognitive benefit. Both note that human research on specific magnesium forms remains limited, and magnesium is needed for many body functions beyond sleep and cognition.
Key Points
- Dr. Patrick says magnesium bisglycinate is her preference for sleep because the attached glycine is also beneficial for sleep.
- Dr. Patrick explains that magnesium L-threonate is thought to cross the blood-brain barrier more readily and support neurotransmission and cognition, but notes most evidence is animal data, with only one small human study showing positive sleep quality reports.
- Magnesium plays a role in more than 3,000 pathways and acts as a cofactor for many enzymes, which is why human research on specific outcomes is sparse.
- Athletes may need more magnesium because magnesium is lost through sweat, and requirements can rise by as much as 20 percent.
- Dr. Patrick cautions that taking L-threonate for the brain may leave less magnesium for DNA repair and other organs, so another magnesium source may be needed.
- Dr. Patrick notes the L-threonate study she found examined Magtein, which the company funded, and clarifies she has no financial relationship with Magtein.
Details Worth Noting
- Concrete instructions: Take magnesium bisglycinate or glycinate about a couple of hours before bed for sleep. On days with more exercise, add a little more magnesium to the mix, since sweat loss increases needs. Consider a separate magnesium source if using L-threonate for cognition, so overall magnesium intake still meets daily requirements.
- Dr. Patrick states that general daily requirement guidance is roughly 300-350 mg for women and 350-400 mg for men, depending on physical activity.
- Magnesium is needed for DNA repair, energy production, neurotransmission, and converting vitamin D3 into its active steroid hormone form.
- Dr. Patrick says about half the US population doesn't get enough magnesium, which she notes can impair the conversion of vitamin D into its active form.
- Chronic stress and high cortisol can deplete magnesium because it is used to manage stress.
- Studies on companies that fund their own research should be considered, as a conflict of interest may exist, though independent studies are expected to blind data.
Bottom Line
Magnesium bisglycinate is the form the speakers prefer for sleep, while magnesium L-threonate is an interesting but less proven option for cognition that requires more research and should not replace overall magnesium intake.
