What to Know About ZMA Supplements
Medically reviewed by Melissa Nieves, LND, RD
ZMA (zinc magnesium aspartate) is a dietary supplement made up of the micronutrients zinc, magnesium, and vitamin B6.
On their own, zinc, magnesium, and vitamin B6 are each vital to a long list of functions and processes in the human body. When combined as ZMA, these nutrients together are promoted as helping to enhance physical performance in athletes. However, there is very little research to back up any claims of ZMA. In fact, there is an extreme lack of studies on the potential health benefits of ZMA, especially in recent years.
This article will focus on the available research on ZMA and what the science says about zinc, magnesium, and vitamin B6 individually. It will also discuss the known side effects, precautions, interactions, and dosage information for ZMA.
Getty Images / Jennifer A Smith
Uses of ZMA
Takeaway
Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian, pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent disease.
Some exercise enthusiasts believe that ZMA supports physical fitness by improving endurance, recovery, and muscle growth. Yet, few studies have been carried out that have proven these claims.
However, because ZMA contains the important nutrients zinc, magnesium, and vitamin B6, it may provide some health benefits.
To understand ZMA's potential uses, it's best to look at the science.
Zinc and Magnesium May Improve Physical Fitness, but Results Are Mixed
Older research has found a possible link between ZMA and better physical fitness. However, some of the research results have been mixed.
ZMA was included in a review on supplements for sports. According to the review, ZMA is a safe supplement for most people, with few reported side effects.
The review also noted research in which simultaneous supplementation with zinc and magnesium was linked to increased quadricep and hamstring power measurements and increased testosterone levels in males.
A small study looked at whether ZMA supplementation improved athletic training. The 42 healthy male participants were randomized to take either a placebo (a substance with no medicinal value) or ZMA before sleep during the eight-week trial. The participants also engaged in resistance training.
By the end of the study, there were no significant differences in body composition, anabolic or catabolic hormones, bench press, leg press, endurance, or cycling anaerobic capacity between the two groups.
In a different study, researchers wanted to test manufacturer claims that ZMA supplementation would increase testosterone levels. The small study included just 14 young, athletically trained men and concluded that ZMA supplementation had no significant effects on testosterone status.
Due to the lack of recent studies and consistent results, more research is needed on ZMA and its effects on physical fitness.
Zinc Supports the Immune System
Zinc is a component of ZMA and an essential mineral, which means you need enough of it regularly for various bodily functions. It's a part of basic metabolism and is instrumental in protein synthesis, wound healing, and development. Zinc has been well-researched for its additional role in immunity.
Research shows that zinc deficiencies may be linked to higher rates of viral illness, including human immunodeficiency virus (HIV) and hepatitis C. Many studies have been conducted on zinc and have concluded that the mineral has therapeutic effects on viral infections and overall immunity.
There is also evidence to suggest a link between zinc status and autoimmune diseases.
According to one review, people with autoimmune diseases may be more likely to have a zinc deficiency. The review also found that low zinc levels are correlated with inadequate white blood cells, higher levels of inflammation, and other risk factors for certain autoimmune diseases.
Magnesium Aids In Energy Production
Similar to zinc, magnesium is another mineral in ZMA that is vital to human health. Magnesium is abundant in foods and supplements and is needed for over 300 metabolic processes.
One of these processes is energy production. Magnesium plays a vital role in the creation of ATP (adenosine triphosphate), the molecule that stores and carries energy. Magnesium also supports the structure and function of proteins, nucleic acids, and mitochondria, which are all integral to energy production and use.
Some athletes use magnesium with the hopes of boosting their performance. Although magnesium aids in muscle function, heart rhythm, blood pressure, and bone health, studies have not been able to come to a consensus on whether the mineral provides any additional benefit for athletes.
A lack of magnesium has been linked to decreased muscle energy and strength, which could cause poor muscle performance. If severe, a magnesium deficiency may lead to weakness, fatigue, muscle pain, and cramps.
Vitamin B6 Supports Brain Health
The third component of ZMA is vitamin B6, which has many essential functions in the body. Vitamin B6 comes in multiple forms and is key to brain health and development.
Adequate vitamin B6 levels have been associated with healthy structures within the brain and spinal cord. And when it comes to conditions like Alzheimer's disease and mild cognitive impairment, decreased levels of vitamin B6 may lead to worse outcomes. One review found that vitamin B6 supplementation may improve symptoms of Alzheimer's disease and cognitive impairment in those with a deficiency, although results are mixed.
Interestingly, co-supplementing vitamin B6 and magnesium may improve mental health, according to one study. An eight-week study found that people with magnesium deficiencies supplementing with magnesium and vitamin B6 had improved self-reported mental health symptoms. Study participants reported better mood and quality of life as well as less anxiety.
What Are the Side Effects of ZMA?
When taking dietary supplements, it's important to be aware of potential side effects.
Few side effects have been directly linked to ZMA supplement use. In the small number of studies performed on ZMA, no side effects have been reported. However, these studies were small in size and few in number.
Although rare, the individual nutrients found in ZMA may cause side effects in some people.
Possible side effects of taking too much zinc include:
Nausea and vomiting
Dizziness
Upset stomach
Possible side effects from taking high doses of magnesium include:
Nausea
Abdominal cramping
Vitamin B6 supplementation is not thought to cause side effects. However, using vitamin B6 in high doses and over a long period may result in ataxia, a loss of control of body movements). Ataxia may become severe if vitamin B6 supplementation is not stopped.
More research is needed on ZMA to determine its overall safety. To reduce your risk of side effects, use ZMA only as directed.
Precautions
Some people may need to take extra precautions before using ZMA.
Due to a lack of research, it is unknown if ZMA is safe for people to use while pregnant or breastfeeding. If you're pregnant or breastfeeding, talk with a healthcare provider before using ZMA, as it may be necessary to avoid it.
There also isn't enough research on the use of ZMA supplements in children. Speak to a healthcare provider if you're considering giving your child ZMA.
More research is needed to determine if any other populations should avoid ZMA. In the meantime, talk with a healthcare provider about using ZMA, especially if you have a medical condition or take any prescription medications.
Dosage: How Much ZMA Should I Take?
Explainer
Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs.
At this time, there are no standardized dosage recommendations for ZMA.
Dosage varies for ZMA and may depend on your reason for use, your age, and other factors. Dosage may also depend on the forms of zinc, magnesium, and vitamin B6 included in the supplement.
In past studies, combinations of zinc and magnesium aspartate were used in 30 mg (milligrams) and 450 mg doses, respectively. No side effects were associated with these doses. However, vitamin B6 was not included.
More research is needed to determine appropriate dosing guidelines for ZMA.
Always follow the dosage directions that are printed on the supplement label, or talk with a healthcare provider about ZMA dosing.
What Happens If I Take Too Much ZMA?
There are no reports of toxicity, overdose, or severe side effects associated with taking too much ZMA, but this may be due to a severe lack of research on the supplement.
Since dosage guidelines don't exist for ZMA, it's difficult to know the consequence of taking too much. However, taking too much will likely lead to side effects.
Keep in mind that there are upper limits for the nutrients in ZMA (zinc, magnesium, and vitamin B6). The upper limit is the highest possible dose of a nutrient you can take (through supplements or food) that is unlikely to cause adverse health events. The upper limits for zinc, magnesium, and vitamin B6 are:
Zinc: 40 mg per day for males and females 19 years and older
Magnesium: 400 mg per day for males and 310 mg per day for females 19 years and older, 420 mg per day for males and 320 mg for females 31 and older
Vitamin B6: 100 mg per day for males and females 19 years and older
To prevent any possible side effects, never take more ZMA than directed.
Interactions
Some substances (like medications, supplements, herbs, or nutrients) may negatively interact with ZMA. Such interactions may cause one or both substances to not work as they should in your body.
While there are no documented interactions for ZMA supplements, there are possible interactions for zinc, magnesium, and vitamin B6.
Zinc may interact with:
Antibiotics (drugs that treat bacterial infections)
Penicillamine (a drug for rheumatoid arthritis and Wilson's disease)
Diuretics (drugs that increase urine output)
Magnesium may interact with:
Bisphosphonates (drugs that treat a loss of bone mass and density)
Antibiotics
Proton pump inhibitors (drugs to control stomach acid)
Vitamin B6 may interact with:
Cycloserine (a drug that treats the lung disease tuberculosis)
Antiepileptic medications (drugs that suppress seizures)
Theophylline (drugs to treat asthma and chronic obstructive pulmonary disease, or COPD)
Other interactions may exist, so be sure to talk with a healthcare provider before using ZMA if you use other supplements, herbs, or medications.
Always carefully read the ingredient list and nutrition facts panel of a supplement to know which ingredients and how much of each ingredient is included. It's recommended that you review supplement labels with a healthcare provider to discuss any potential interactions with foods, other supplements, and medications.
How to Store ZMA
Proper storage of supplements helps maintain their freshness and quality.
ZMA supplements should be stored in a cool, dry place that is kept out of direct sunlight. It's important that your supplements never get too hot or cold. ZMA supplements do not require refrigeration. It's best to keep supplements in their original container. ZMA supplements should be kept in an airtight container.
Keep ZMA supplements out of reach of pets and small children who may accidentally ingest them.
Be sure to throw away any ZMA supplements that have spoiled or expired. The expiration date is usually listed on the packaging or label.
Similar Supplements
The biggest claim surrounding ZMA is that it enhances athletic performance (although research has yet to confirm this). Other dietary supplements may act similarly and also improve athletic performance, including:
Beetroot juice
Beta-alanine
Betaine
Branched-chain amino acids
Tart cherry
These supplements are thought to increase endurance, muscle mass, recovery, and other factors related to physical performance. However, research results are mixed.
It's often recommended to take one supplement at a time for a specific health purpose. Please talk with a healthcare provider about which supplement may be right for you.
Frequently Asked Questions
Is ZMA safe?
It's not known. Safety studies have not been performed on ZMA. And while no side effects have been reported in the research on ZMA, very few studies have been performed. Use ZMA only as directed on the product label.
Is ZMA good for testosterone?
There is no solid evidence that ZMA improves levels of testosterone, the primary male reproductive hormone.
In an older study (from 2009), ZMA supplementation did not significantly increase testosterone levels in healthy young men. More research is needed to determine if ZMA plays any role in testosterone levels.
Does ZMA work?
It's not known. Very little research has been conducted on ZMA, so its effectiveness can't be determined. Most studies were done in the early 2000s and only looked at ZMA's potential use in physical performance. For the most part, these studies did not find that ZMA enhances performance, but more research is needed.
Will ZMA help me sleep?
There is no research on ZMA's effect on sleep, but one of the ingredients in ZMA, magnesium, may improve sleep.
According to a recent review, observational studies have found a link between magnesium intake and healthy sleeping patterns, but controlled trials have had mixed results. Larger-scale studies are required to determine the relationship between magnesium and sleep.
Does ZMA expire?
Like other supplements, ZMA will eventually expire. Many supplements are thought to be good for about two years, but this can vary.
Once ZMA supplements reach expiration, they may be less potent. The expiration date should be listed on the supplement packaging or label.
Sources of ZMA & What to Look For
ZMA is only available as a dietary supplement, but zinc, magnesium, and vitamin B6 are found in various foods.
It's best to take a food-first approach to your nutrition whenever possible. Most people can get all the zinc, magnesium, and vitamin B6 their bodies need through a well-balanced diet. Typically, these nutrients are thought to be best absorbed from foods rather than supplements.
Food Sources of ZMA
Although ZMA is not found naturally in foods, the nutrients within it are.
Zinc is primarily found in animal foods, including meat, fish, and poultry. Other sources of zinc include:
Fortified breakfast cereals
Pumpkin seeds
Dairy products
Peanuts
Eggs
Beans
Magnesium is easily found in many plant and animal foods. These include:
Nuts and seeds
Edamame
Potatoes
Oats
Yogurt
Bananas
Beef
Chicken
Vitamin B6 is also available in a wide variety of foods. Foods that contain vitamin B6 include:
Chickpeas
Seafood
Beef
Chicken
Potatoes
Cottage cheese
Winter squash
Bulgur
These nutrients are found in many additional foods and should be consumed daily for health.
ZMA Supplements
You can purchase ZMA supplements online or in certain grocery, retail, or nutrition stores. ZMA is mostly sold as capsules but is also available in powder, gummy, and tablet forms.
The majority of ZMA supplements are naturally gluten-free. Many options are also vegan and organic. These specifications should be listed on the packaging or supplement label.
When shopping for ZMA, it's important to remember that there is still very little research on it. Therefore, it's important to buy ZMA from a reputable brand.
It's also best to look for ZMA supplements approved by a third-party agency like U.S. Pharmacopeia (USP), NSF, or ConsumerLab.com. These agencies provide voluntary reviews to ensure that products have accurate nutrition labels and do not contain contaminants.
Summary
ZMA is a manufactured dietary supplement containing zinc, magnesium, and vitamin B6 micronutrients. It is mostly thought to improve athletic performance, but no solid evidence supports this claim. It's vital that more research be done on ZMA to learn more about its safety and potential benefits.
Remember that supplements are mostly unregulated by the Food and Drug Administration (FDA) or other government agencies. Always do your research and talk with a healthcare provider before using a new supplement.
Read the original article on Verywell Health.
