Zinc magnesium aspartate (ZMA) is a dietary supplement containing zinc, magnesium, and aspartic acid. It is frequently marketed to support the male reproductive system, particularly for its claimed effects on testosterone levels, fertility, and sexual health. The scientific evidence supporting these claims is limited and mixed.

Zinc is an essential mineral involved in numerous enzymatic processes, including those related to testosterone synthesis and sperm production. Deficiency in zinc has been associated with hypogonadism and impaired reproductive function in men. Supplementation in zinc-deficient individuals can restore normal testosterone levels and improve sperm quality. Magnesium also plays a role in hormone regulation and may have a minor supportive effect on testosterone bioavailability, although the evidence is less robust than for zinc. Aspartic acid has been studied for its potential to increase luteinizing hormone and testosterone, but results are inconsistent.

However, in healthy, non-deficient males, high-quality studies (such as those by Brilla & Conte, 2000, and Wilborn et al., 2004) have generally failed to show significant increases in testosterone or improvements in reproductive parameters with ZMA supplementation. The overall scientific consensus is that ZMA may be beneficial for individuals with existing deficiencies but does not enhance male reproductive function in healthy men.

In summary, while there is some scientific basis for ZMA's use in addressing deficiencies relevant to the male reproductive system, evidence for its effectiveness as a general supplement for reproductive health is weak.