Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Font Size

What Is ZMA?

ZMA is a natural mineral supplement made up of zinc, magnesium aspartate, and vitamin B6. Zinc supports your immune system and muscles. Magnesium plays a role in metabolism and muscle health and helps manage sleep. B6 may boost energy.

ZMA makers claim that increasing these three nutrients in your system can build muscle strength and stamina, speed muscle recovery, and improve the quality of your sleep.

But there’s not a lot of research to back that up.

In 2000, researchers gave ZMA supplements to a group of NCAA football players working out twice a day. After 7 weeks, they found a significant increase in the players’ testosterone and growth hormone, both of which are linked to muscle growth. However, one of the scientists who conducted the study holds the registered trademark for the original formula of ZMA, and his company funded the research.

Further experiments done by other scientists haven’t duplicated the same effects. In fact, there’s no additional research that ZMA aids athletic performance or weight loss.

Because of that, the International Society of Sports Nutrition has declared ZMA’s effect on muscle building “not known,” and the Australian Institute of Sport, which informs athletes about supplements, has decided that ZMA is lacking clear proof of benefits. There are no similar supplement-rating organizations in the U.S.

Are There Side Effects?

No major side effects of ZMA have been reported, but there could be health concerns if the supplements are taken more frequently than the manufacturer suggests.

Too much zinc or magnesium can cause diarrhea, nausea, and cramping, and when taken in high doses over a period of time, zinc can lower the body’s immunity and its levels of HDL, or “good,” cholesterol. One study also found that men who took 100 milligrams of zinc supplements for 10 years were more likely to get prostate cancer, but the reason isn't clear. Taking extremely high levels of B6 for a year or more may cause nerve damage.

More immediate concerns: Zinc and magnesium can make it harder for your body to absorb some prescription medications, such as antibiotics; and B6 supplements can intensify the side effects of certain drugs.

Vitamins and
Lifestyle Guide

Which Nutrients
Are You Missing?

Learn More

Today on WebMD

vitamin rich groceries
Do you know your vitamin ABCs?
St Johns wart
Ease hot flashes and other symptoms.
Are you getting enough?
Take your medication
Wonder pill or overkill?
fruits and vegetables
Woman sleeping
Woman staring into space with coffee

Send yourself a link to download the app.

Loading ...

Please wait...

This feature is temporarily unavailable. Please try again later.


Now check your email account on your mobile phone to download your new app.