What he says about magnesiumglycinate and its dosign

Magnesium glycinate may help with sleep, but no specific dose for glycinate is given in the relevant dosage recommendation.

• Tissue selectivity and sleep: Huberman says glycinate appears similar to threonate in the tissues it is shuttled to; threonate is described as more readily reaching the brain and engaging GABA-related pathways that can help quiet thinking for sleep. 1
• Dose distinction: He gives 145 mg for magnesium threonate as a dose many people may benefit from, while noting individual needs can be higher or lower. That number is for threonate, not glycinate. 2
• Individual response and caution: Responses vary; some people need no supplement, and magnesium can cause digestive discomfort. Huberman also advises caution because magnesium may be involved in heart rhythm, and recommends discussing supplement changes with a physician. 3