ZMA, or zinc magnesium aspartate, is a popular supplement among athletes, bodybuilders, and fitness enthusiasts.
It contains a combination of three ingredients — zinc, magnesium, and vitamin B6.
ZMA manufacturers claim it boosts muscle growth and strength and improves endurance, recovery, and sleep quality.
What is ZMA?
ZMA is a popular supplement that typically contains the following:
- Zinc monomethionine: 30 mg — 270% of the Reference Daily Intake (RDI)
- Magnesium aspartate: 450 mg — 110% of the RDI
- Vitamin B6 (pyridoxine): 10–11 mg — 650% of the RDI
However, some manufacturers produce ZMA supplements with alternative forms of zinc and magnesium, or with other added vitamins or minerals.
These nutrients play several key roles in your body:
- Zinc. This trace mineral is necessary for more than 300 enzymes involved in metabolism, digestion, immunity, and other areas of your health.
- Magnesium. This mineral supports hundreds of chemical reactions in your body, including energy creation and muscle and nerve function.
- Vitamin B6. This water-soluble vitamin is needed for processes such as making neurotransmitters and nutrient metabolism.
Athletes, bodybuilders, and fitness enthusiasts often use ZMA.
Manufacturers claim that increasing your levels of these three nutrients can help increase testosterone levels, aid exercise recovery, improve sleep quality, and build muscle and strength.
However, the research behind ZMA in some of these areas is mixed and still emerging.
That said, consuming more zinc, magnesium, and vitamin B6 may provide many other benefits, such as improved immunity, blood sugar control, and mood. This especially applies if you’re deficient in one or more of the aforementioned nutrients.
ZMA and athletic performance
ZMA supplements are claimed to enhance athletic performance and build muscle.
In theory, ZMA may enhance these factors in those who are deficient in zinc or magnesium.
A deficiency in either of these minerals may reduce your production of testosterone, a hormone that affects muscle mass, as well as insulin-like growth factor (IGF-1), a hormone that affects cell growth and recovery.
In addition, many athletes may have low zinc and magnesium levels, which can compromise their performance. Lower zinc and magnesium levels may be the result of strict diets or losing more zinc and magnesium through sweat or urination.
Currently, only a few studies have looked into whether ZMA can improve athletic performance.
One 8-week study in 27 football players showed taking a ZMA supplement daily significantly increased muscle strength, functional power, and testosterone and IGF-1 levels.
However, another 8-week study in 42 resistance-trained men found that taking a ZMA supplement daily did not raise testosterone or IGF-1 levels when compared to a placebo. Furthermore, it did not improve body composition or exercise performance.
What’s more, a study in 14 healthy men who exercised regularly showed that taking a ZMA supplement daily for 8 weeks did not raise total or free blood testosterone levels.
It’s worth noting that one of the authors of the study that found ZMA improved athletic performance has ownership in the company that produced the specific ZMA supplement. That same company also helped fund the study, so there may be a conflict of interest.
Individually, both zinc and magnesium have been shown to reduce muscle fatigue and either raise testosterone levels or prevent a fall in testosterone due to exercise, though it’s unclear if they’re more beneficial when used together.
All told, it’s unclear whether ZMA improves athletic performance. More research is needed.
Benefits of ZMA supplements
Studies on ZMA’s individual components suggest that the supplement may offer several benefits.
May boost immunity
Zinc, magnesium, and vitamin B6 play key roles in your immune health.
For example, zinc is essential for the development and function of many immune cells. In fact, supplementing with this mineral may reduce your risk of infections and aid wound healing.
Meanwhile, magnesium deficiency has been linked to chronic inflammation, which is a key driver of aging and chronic conditions like heart disease and cancer.
Conversely, taking magnesium supplements may reduce markers of inflammation, including C-reactive protein (CRP) and interleukin 6 (IL-6).
Lastly, vitamin B6 deficiency has been linked to poor immunity. Your immune system requires vitamin B6 to produce bacteria-fighting white blood cells, and it enhances their ability to combat infection and inflammation.
May aid blood sugar control
Zinc and magnesium may help people with diabetes control their blood sugar levels.
An analysis of 25 studies in over 1,360 people with diabetes showed that taking a zinc supplement reduced fasting blood sugar, hemoglobin A1c (HbA1c), and post-meal blood sugar levels.
In fact, it found that supplementing with zinc lowered HbA1c — a marker for long-term blood sugar levels — to an extent similar to that of metformin, a popular diabetes dru.
Magnesium may also improve blood sugar control in people with diabetes by improving the body’s ability to use insulin, a hormone that moves sugar from your blood into cells.
In fact, in an analysis of 18 studies, magnesium was more effective at reducing fasting blood sugar levels than a placebo in people with diabetes. It also significantly reduced blood sugar levels in those at risk of developing diabetes.
May help improve your sleep
The combination of zinc and magnesium may improve your sleep quality.
Research suggests that magnesium helps activate the parasympathetic nervous system, which is responsible for helping your body feel calm and relaxed.
Meanwhile, supplementing with zinc has been linked to improved sleep quality in both human and animal studies.
An 8-week study in 43 older adults with insomnia showed that taking a combination of zinc, magnesium, and melatonin — a hormone that regulates sleep-wake cycles — daily helped people fall asleep faster and improved sleep quality, compared to a placebo.
May elevate your mood
Magnesium and vitamin B6, both of which are found in ZMA, may help elevate your mood.
One study in approximately 8,900 adults found that those under the age of 65 with the lowest magnesium intake had a 22% higher risk of developing depression.
Another 12-week study in 23 older adults showed that taking 450 mg of magnesium daily reduced depression symptoms as effectively as an antidepressant drug.
Several studies have linked low blood levels and intakes of vitamin B6 to depression. However, taking vitamin B6 doesn’t appear to prevent or treat this condition