ZMA is a combination of zinc monomethionine/asparate and magnesium aspartate plus vitamin B6. It's strongly supported by clinical research to be an effective supplement for enhancing muscle recovery, boosting muscle size and strength, and even aiding fat loss.*

I've been recommending ZMA supplementation for many years. Yet because ZMA is just a mineral supplement—and other supplements like creatine and NO-boosters seem to promise more—few people feel the need to bother with ZMA. That's unfortunate. If you're someone who doesn't feel that taking ZMA is critical for your results, you may change your mind after reading this article.

ZMA is not a testosterone booster. Yes, research shows that it may help athletes maintain higher testosterone levels during intense training periods, though it is not designed to boost levels of the primary muscle-building hormone. It's simply the most effective way to supplement with two very critical minerals: zinc and magnesium.

Minerals Matter

Zinc is an essential mineral with antioxidant properties that stimulates the activity of many enzymes in the body. These enzymes are critical for numerous biochemical reactions. Zinc has been found to be critical for protein synthesis, the molecular mechanism that leads to muscle recovery and growth.


Numerous research studies have suggested that zinc and magnesium help enhance muscle size, muscle strength, and fat loss, not to mention overall health and well-being.*

Magnesium is also an essential mineral involved in numerous reactions in the body. It's important for healthy function of the cardiovascular system, metabolic rate, and of course bone health.* Together, zinc and magnesium offer a wide assortment of physique and performance benefits.

In fact, numerous research studies have suggested that these two minerals help enhance muscle size, muscle strength, and fat loss, not to mention overall health and well-being.*

Anabolic Factors

Research suggests that ZMA has significant anabolic benefits. A study performed at Western Washington University (Bellingham) had NCAA football players take ZMA or a placebo every night during an eight-week spring training program. They reported that the athletes taking the ZMA supplement experienced more than a 30-percent increase in testosterone levels, and about a 5-percent increase in levels of the insulin-like growth factor 1 (IGF-1).* Those taking a placebo had a 10-percent decrease in testosterone levels and a greater than 20-percent decrease in levels of IGF-1.

In addition to the improvements in their anabolic hormone levels, the ZMA-supplemented athletes made significantly greater gains in strength and power, and achieved better sleep quality, than a placebo group. Better sleep quality also helps to aid muscle recovery from tough workouts. These benefits occurred in the ZMA group despite the fact that the analyses of their diets found that the athletes were all consuming well over the recommended intake for zinc. In addition to the study performed by the Western Washington University researcher, several other studies have also found that zinc and magnesium offer potent anabolic properties.*


Better sleep quality also helps to aid muscle recovery from tough workouts.

A 2007 study from Selcuk University (Konya, Turkey) reported that four weeks of zinc supplementation in men increased testosterone levels at rest and after exercise.* The same researchers also found similar results for zinc supplementation on testosterone levels in a prior study with competitive wrestlers. Researchers from the USDA reported that zinc depletion decreased muscle endurance in subjects. This means that maintaining optimal zinc levels is critical for your ability to complete a number of reps with a given weight.

The same Western Washington University research team that did the ZMA research also discovered in an earlier study that when subjects supplemented with magnesium while following a 7-week leg training program, their leg strength increased by 20-percent more than those taking a placebo.*

Both zinc and magnesium are also suggested to blunt cortisol, a catabolic hormone. German researchers found that triathletes taking a magnesium supplement for four weeks maintained healthy cortisol levels at rest and after a triathlon, as compared to athletes taking a placebo. And Brazilian researchers also reported that subjects supplementing with zinc maintained healthy cortisol balance.

ZMA may also boost growth hormone (GH) levels, albeit indirectly. ZMA enhances sleep quality due to magnesium's ability to normalize and extend stage 3 and stage 4 slow-wave sleep. This is critical, as deeper sleep can help to raise GH levels, which peak during the night.

Metabolic Muster

Zinc is also critical for maintaining thyroid hormone production. This is important for keeping your metabolic rate (the amount of calories you burn each day) and fat-burning capabilities up. Being low in zinc can limit thyroid hormone production, and compromised thyroid hormone function results in a lower metabolic rate, which makes it harder to drop body fat. Research confirms that when your diet is low in zinc, thyroid hormone levels fall and resting metabolic rate drops.

One study from the University of Massachusetts (Amherst) found that subjects placed on a low-zinc diet had significantly lowered metabolic rates. When the subjects took 25 mg of zinc each day for 20 days, their metabolic rate jumped up to levels that were higher than even before they followed the low-zinc diet.* The Selcuk University studies also showed that four weeks of zinc supplementation increased thyroid hormone levels in male wrestlers and sedentary men.

It appears that zinc is not only critical for thyroid function, but also for maintaining levels of the hormone leptin. This hormone is also important for keeping your metabolic rate high as well as keeping hunger down. Being deficient in zinc has been shown to significantly lower leptin levels.

Support Immunity

It is well established that zinc is critical for immune function. Zinc affects multiple aspects of the immune system. Research from the Cleveland Clinic suggests that supplementing with zinc helps to support a strong immune system.

Zinc also functions as a powerful antioxidant. This mighty mineral activates an enzyme that may help support overall health and immune function.* Zinc's powerful antioxidant properties can enhance not just your health but your post-workout recovery as well. Zinc's immune-boosting effects can help to keep you healthy and in the gym.

Yes, You're Deficient

Research has confirmed that athletes are often deficient in both zinc and magnesium. This is most likely due to several factors, such as zinc lost through sweat during training, increased use of zinc by the body for recovery and protein synthesis following training, and an increased loss of zinc through urine. There may also be dietary factors involved.


Refined sugars, as well as white-flour products such as white bread, can lower blood levels of zinc and magnesium.

Refined sugars, as well as white-flour products such as white bread, can lower blood levels of zinc and magnesium. Foods rich in calcium, such as dairy products, inhibit absorption of both zinc and magnesium by the small intestines. Copper, as well as foods rich in phytates (phosphorous compounds found in whole-grain breads, cereals, and legumes) also hinder the absorption of zinc by the small intestines. And alcohol decreases the absorption of zinc and magnesium, and increases their loss through urine.

Given that you likely are not adequately absorbing the zinc from your whole foods, and that you are losing large amounts of the zinc that you do absorb, you should seriously consider taking a ZMA supplement to maximize muscle mass and strength gains, as well as to drop body fat and support healthy immune function.

If you are using my Vita JYM multivitamin, it is critical that you use ZMA. I omitted zinc and magnesium from Vita JYM to prevent their competition with other nutrients, and to allow for the maximal uptake and utilization of zinc through ZMA.

Do's and Don'ts

  • While taking a plain zinc and magnesium supplement together may provide you with adequate amounts of these important minerals and cost less than a ZMA supplement, I still suggest you spend the money on ZMA. The form of zinc and magnesium used in ZMA is a chelate known as zinc monomethionine/aspartate and magnesium aspartate.

    This form helps to minimize interference in the absorption of both these minerals. Furthermore, this form of ZMA provides zinc and magnesium aspartate in the proper dosage, while also serving up the proper amount of vitamin B6, which aids magnesium uptake and utilization by the body.

  • Specific dosages were found to produce positive effects in athletes' hormone and strength levels. Men should look for ZMA supplements that provide 30 mg of zinc, 450 mg of magnesium, and 10-11 mg of B6; no more, no less. Women should take a 20 mg dose of zinc, 300 mg of magnesium, and 6-7 mg B6. Since a full dose of ZMA is usually 3 capsules, the dose for women can be achieved by taking 2 capsules. Also, be sure that it lists ZMA from SNAC Systems on the label. Anything else is not true ZMA.

  • Be aware that, with zinc, there can be too much of a good thing. Taking in too much zinc—upwards of 50 mg of absorbed zinc— can lead to negative effects on the immune system and metabolic rate, adversely impact muscle recovery and growth, and even reduce levels of HDL (good) cholesterol. It can also interfere with copper uptake. In other words, the effects will be the opposite of what's intended in the first place.

  • What about magnesium? Taking more than 450 mg of it can actually interfere with optimal sleep.

  • One of the most important aspects of supplementing with ZMA is timing. I have always recommended taking it about 1 hour before bed and 1-2 hours after you eat. This will not only help to maximize its uptake and utilization, as clinical research confirms, but taking ZMA at this time of day will also enhance sleep quality.

  • It's critical that you do not take ZMA with any food, particularly food rich in calcium, like dairy. Both zinc and magnesium are poorly absorbed when taken with food. Sometimes, it's a two-way street. Calcium, for example, interferes with zinc uptake while zinc interferes with the absorption of amino acids. One way to enhance the uptake of ZMA is to take it with 5 mg of BioPerine, a black pepper extract that's been found to enhance absorption.

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

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About the Author

Jim Stoppani, Ph.D.

Jim Stoppani, Ph.D.

Jim Stoppani holds a doctorate in exercise physiology from the University of Connecticut and has been the personal nutrition and health consultant to numerous celebrity clients, including...

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