ZMA is a dietary supplement comprising a combination of zinc monomethionine aspartate and magnesium aspartate, together with vitamin B6. This trademarked product is used primarily by gymnasts, body-builders and athletes, very frequently as an aid to muscle recovery after strenuous exercise. Some research indicates that it may help to achieve deeper levels of beneficial REM sleep.
The manufacturer also claims that it can enhance strength levels and possibly also hormonal profiles, increasing testosterone and libido, and independent clinical trials are proceeding. All three of the main components in ZMA are important to human biochemistry, and magnesium and zinc supplementation may be necessary for many sectors of the population, although most sources indicate that zinc and vitamin B6 deficiencies are rare in developed countries.
Particularly high concentrations of zinc are present in semen, however, which makes it a crucial factor in the functioning of the prostate gland and growth of the male reproductive organs, while magnesium is important for nerve and muscle functions, and B6 is a cofactor for several of the neurotransmitters which may evoke calm and better sleep. Many athletes attest to the efficacy of ZMA in enhancing their sleep quality and recovery time.