Summary
ZMA is a supplement formulation composed of zinc monomethionine aspartate, magnesium aspartate, and vitamin B6 that is claimed to increase testosterone levels.[1] Supplementation with ZMA was first tested in humans by the supplement’s manufacturer, which found that ZMA raised testosterone levels and increased muscle strength and power in athletes.[2] However, follow-up studies by independent groups have failed to replicate those initial results.[3][4]
