The Side Effects Of Zinc Monomethionine Aspartate

Since its creation in the late 1990s, zinc monomethionine aspartate, or ZMA, has been used by a variety of athletes and bodybuilders. The proposed purpose of ZMA is to help you increase your anabolic hormones, like testosterone, while decreasing your catabolic hormones, like cortisol, along with helping to increase your strength.

What is ZMA?

ZMA is the combination of two minerals, zinc and magnesium, and one vitamin, B6. Most ZMA supplements contain approximately 30 mg of zinc, 450 mg of magnesium, and 10.5 mg of vitamin B6. Since its original creation, some companies have added additional ingredients to the formula. Side effects of ZMA are associated with each vitamin or mineral individually, not the supplement as a whole.

Side Effects of Zinc

The upper limit, or UL, for zinc is 40 mg per day. The upper limit for a vitamin or mineral is the largest amount an individual can consume with toxicity symptoms. The main side effect associated with zinc consumption over the UL is interference with copper metabolism, which would mean individuals approaching the UL would need to consume more copper. Registered dietitian Gordon Wardlaw states that zinc consumption greater than 100 mg per day can result in diarrhea, cramps, nausea, vomiting and a depressed immune system.

Side Effects of Magnesium

The UL for magnesium is 350 mg per day. This is more for supplemental sources of magnesium than food sources. In the text "Advanced Nutrition and Human Metabolism," the authors state that exceeding the UL is generally only a problem for individuals with impaired kidney function. Toxicity symptoms include diarrhea, weakness, nausea, slowed breathing, coma and death.

Side Effects of Vitamin B6

The UL for vitamin B6 is 100 mg per day. Most water-soluble vitamins do not have a toxicity if over-consumed. However, high intakes of vitamin B6 is associated with nerve damage. In order for nerve damage to occur, individuals usually need to consume 2 to 6 g of B6 for periods of two months or more. However, the UL is set at 100 mg per day. It is unlikely that individuals will consume 100 mg of B6 per day coming from food sources.