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(Zinc Magnesium Aspartate, Zinc Monomethionine Aspartate)

What is it?

A combination of the minerals zinc and magnesium.

Does it occur naturally in the body?


What are the claims?

It is supposed to increase free testosterone levels by over 40% without prohormones.

Does it work?

Research is scarce, but in a study by Dr. Lorrie Brilla of Western Washington University, 24 bodybuilders who were heavy supplement users and had low ZMA levels saw strength increases after supplementing with ZMA. That was in the year 2000.

Since then, millions of dollars of ZMA supplements have been sold without a single study to determine if ZMA supplementation had any benefit for people who had normal levels of Zinc and/or magnesium in their bodies.

Then there was the 2007 study conducted at the Karaman High School of Physical Education and Sport, Selcuk University, Karaman in Turkey. For four weeks, researchers studied this:

"The effects of magnesium supplementation on plasma magnesium, zinc, and copper levels were determined in young adult tae-kwon-do athletes and sedentary controls at rest and exhaustion."

What did they discover? After four weeks, they found that both athletes and non-athletes alike can increase their plasma magnesium, copper and zinc levels when they take Zinc and Magnesium supplements.

You read that right. The test was to see if taking a supplement would increase the amount of supplement in the athlete's body. Obviously, it did.

What they didn't test for was to see if that supplement had any long term benefit for strength gain or muscle mass increase. After all, that's what ZMA is being marketed as doing.

We challenge the supplement industry to actually conduct a test and see if ZMA supplementation helps build muscle or increase strength. We also want to know how much ZMA should be taken, in what form and what increases can be expected. As of 9/28/2008, no such studies exist.

What are the dangers?

Stomach upset, bloating, gas or diarrhea have been reported. In recent studies, if you take in 100 milligrams or more of zinc daily, you may be at increased risk for prostate cancer.

The Bottom Line

If you have your zinc and magnesium levels tested, and you are low, you might benefit from taking this supplement. There do not appear to be beneficial effects (such as muscle growth) that can be attributed to taking this supplement for people who have normal levels of zinc or magnesium.

Unless prescribed by a doctor for a medical condition, we cannot recommend the supplement combination known as ZMA for people simply looking to build muscle.

Links for More Info

Centers for Disease Control and Prevention (CDC) Logo and Link
Centers for Disease Control and Prevention

United States Food and Drug Administration (FDA)

Herbs, Botanicals & Other Products - Extensive Information from the Memorial Sloan-Kettering Cancer Center

National Center for Complementary and Integrative Health - Overviews on Herbal Treatments and Supplements

National Institutes of Health

National Institutes of Health - Office of Dietary Supplements
National Institutes of Health - Office of Dietary Supplements

Operation Supplement Safety
Operation Supplement Safety

United States Department of Agriculture (USDA) Logo and Link
United States Department of Agriculture

WebMD Logo and Link
WebMD - Helping you make better decisions for life.

We at WeBeFit DO NOT recommend ANY supplements to ANY of our clients. ONLY a licensed Nutritionist or Medical Doctor can make those recommendations based on your individual needs.

This is being provided for INFORMATIONAL and EDUCATIONAL purposes only.

CAUTION: These supplements have not been evaluated by the Food and Drug Administration (FDA) for safety, effectiveness or purity. There may be unknown risks associated with taking any supplements. There are no regulated manufacturing standards for companies that make supplements. There have been instances where herbal or health supplements have been sold that were contaminated with toxic substances. If you should choose to purchase herbal or health supplements, please only purchase them from a reliable source to minimize the risk of contamination.

If you should decide to use ANY supplement, ALWAYS consult your doctor or Nutritionist first.