Magnesium Glycinate
The most under-supplemented mineral for testosterone, sleep, and muscle recovery.
What is Magnesium Glycinate?
Magnesium is an essential mineral involved in over 600 enzymatic reactions, including testosterone synthesis, muscle contraction, nerve function, and sleep regulation. It is found in leafy greens, nuts, and seeds, but dietary surveys consistently show that over 50% of UK adults consume less than the recommended daily amount. Physical training and stress both accelerate magnesium loss.
What does the evidence say?
A 2011 study by Cinar et al. in Biological Trace Element Research found magnesium supplementation at 10mg/kg/day significantly increased both free and total testosterone in athletes and sedentary men. A 2012 study by Wienecke and Nolden showed reductions in muscle cramps and improved sleep quality. Research by Abbasi et al. (2012) found 500mg of magnesium daily improved sleep quality in elderly men by reducing cortisol and increasing melatonin levels.
Multiple high-quality randomised controlled trials with consistent results and independent replication.
Dosage guide
| Effective dose | 300–400mg of elemental magnesium per day |
| Maximum dose | 350mg/day from supplements (NHS guidance); food-derived magnesium has no established upper limit |
| Timing | Evening, 30 to 60 minutes before bed, the sleep-promoting effects are most useful overnight. |
Best form to buy
Magnesium glycinate (bisglycinate) for sleep and general use: high bioavailability, gentle on the gut. Magnesium L-threonate for cognitive applications, as it crosses the blood-brain barrier. Avoid magnesium oxide: it has very poor absorption and is mainly used as a laxative.
Who benefits most
Essentially any man who trains regularly, experiences poor sleep, or consumes alcohol. Vegetarians and vegans eating enough leafy greens may be less deficient.
Side effects and safety
Glycinate form is well tolerated. Other forms (especially oxide, citrate at high doses) can cause loose stools. Taking too much too fast may cause temporary diarrhoea.
“This is the second supplement I'd recommend to any man, after creatine. Most people are deficient, it's cheap in the glycinate form, and the sleep improvements alone are worth it within a week. Get the bisglycinate or glycinate form, not oxide.”