Can Vitamins or Supplements Make You Fail a Drug Test?

Supplements and drug tests at a glance

This page is about drug tests in sport, such as NCAA, United States Anti-Doping Agency (USADA) and World Anti-Doping Agency (WADA) testing.

Can a vitamin make you fail a drug test?

A real vitamin will not. No vitamin or mineral is in any of the NCAA's eight banned drug classes. Our guide to whether vitamins are allowed in the NCAA covers that in detail.

The problem is the product, not the vitamin. The NCAA's own warning says supplements, "including vitamins and minerals, are not well regulated and may cause a positive drug test". It also says supplements "may be contaminated with banned substances not listed on the label".

So a product labelled "multivitamin" can hold more than vitamins, whether it is a tablet, a capsule or a powder. A drug test finds what is in your body, not what is on the label.

How does a banned substance get into a supplement?

There are two main ways.

• Contamination. A contaminant is something in a product that should not be there. The World Anti-Doping Code calls a product contaminated when it holds a banned substance that is not on the label or easy to find online.
• Spiking. Some products have a drug added on purpose. USADA says it is "well documented that some dietary supplements have been contaminated or spiked with performance-enhancing drugs".

The FDA describes the same problem. It says a product with hidden ingredients "is contaminated with ingredients that are not listed on the product label". It adds that these hidden ingredients "are often prescription drug ingredients, banned substances and/or harmful chemicals".

Part of the reason is how supplements are sold. The FDA does not approve dietary supplements or vitamins before they go on sale. In the United States, the company is responsible for checking its own product's safety and label first, and the FDA can act after a product reaches the market.

How common is it?

Common enough that the NCAA, USADA and the FDA all warn about it.

One large study, by Geyer and colleagues in 2004, bought 634 supplements from 215 suppliers in 13 countries. All were non-hormonal, meaning they were not sold as hormone products. Yet 94 of them, about 15%, held anabolic steroids (muscle building drugs) that were not on the label.

The study found one more pattern. Products from companies that also sold prohormones (substances the body turns into steroid hormones) tested positive 21.1% of the time. Products from companies that did not sell them tested positive 9.6% of the time.

For a more recent test of the same problem, see our write up of the one in three supplements survey.

Which supplements carry the most risk?

Some kinds of products show up again and again. The FDA says to "be especially wary of products sold for sexual enhancement and energy, weight loss, pain, bodybuilding or sleep".

USADA points to the same FDA guidance. It names muscle building, weight loss and energy, and sexual enhancement products as the ones most often spiked, and advises athletes to avoid those categories.

USADA also lists warning signs on a label:

• "All natural" products sold as an alternative to a prescription drug
• Big promises, like a "secret formula" or a "quick fix"
• Claims of being "clinically proven" or "university approved" with no research you can check
• Claims that an anti-doping agency endorses the product. USADA says neither it nor WADA endorses or approves supplements

The FDA keeps a health fraud product database of contaminated products it has found. But it says the database "covers only a small fraction of the contaminated and/or fraudulent products on the market". If a product is not on the list, that does not mean it is safe.

Has a vitamin or supplement really cost athletes their careers?

Yes. Two swimmers' cases show how it happens.

Kicker Vencill tested positive in an out of competition test on January 21, 2003. His sample held a metabolite (a breakdown product) of nandrolone, a banned anabolic agent. He blamed a common multivitamin. A 2005 jury found it contaminated with three steroid precursors, though that verdict was later set aside.

The Court of Arbitration for Sport (CAS), the top court for sport disputes, accepted that he did not know. It still found he "exercised not the slightest caution" and banned him for two years. He missed the 2003 Pan American Games and the 2004 U.S. Olympic Swimming Trials.

Read the full story of Kicker Vencill's contaminated multivitamin.

Jessica Hardy made the 2008 U.S. Olympic team in four events. Her test from July 4, 2008 came back positive for clenbuterol, a banned substance. It came from a supplement whose label did not list it.

Proving that cut her ban to one year, but she still withdrew from the Beijing team. See Jessica Hardy's contaminated supplement case for how it played out.

What does "I did not know" get you?

Very little. The rule is called strict liability: you are responsible for what is in your sample, whether or not you meant to take it.

Under WADA and USADA rules

The World Anti-Doping Code says it is each athlete's "personal duty to ensure that no Prohibited Substance enters their bodies". A violation does not require proof of intent, fault or knowing use. USADA is the independent anti-doping agency for Olympic sport in the United States.

Not knowing can sometimes cut the penalty, but it never erases the violation:

• No fault at all removes the ban. The Code says this does not apply to "a mislabeled or contaminated vitamin or nutritional supplement".
• A proven contaminated product can bring the ban down to anything from a reprimand (a formal warning) to two years. You must prove the product was the source, and that you bore no significant fault.
• That reduction is rare. The Code says it "has rarely been applied in Contaminated Product cases unless the Athlete has exercised a high level of caution".

Without a reduction, the standard ban for a first violation is two or four years. Which one depends on the substance and on whether it was intentional.

Under NCAA rules

The NCAA says student athletes "are held responsible for their use of all banned substances at all times". It also says all supplements are taken at the student athlete's own risk.

Under the 2026 to 27 Division I Manual, a first positive test for anything but narcotics has two parts:

• You are withheld from one full season of regular season competition.
• You are ineligible for 365 days from the test, and until you test negative.

You can appeal through your school, and the appeal panel can consider "asserted mitigation". Mitigation means facts that might lessen the penalty. You stay ineligible while the appeal runs.

If you compete in Division II or III, ask your compliance office for your division's rules.

How can you lower the risk?

You cannot remove it. Even the NCAA says "complete elimination of risk is impossible". But you can lower it a lot.

1. Scan it in Varsity Stack first. Check the barcode or label against our certification database before you buy.
2. Ask your athletics staff before you take anything. The NCAA makes this your responsibility.
3. Choose a product certified by a banned substance testing program. USADA recommends using only third party certified products, and recognizes NSF Certified for Sport. USADA says NSF Certified for Sport products "significantly reduce, but do not necessarily eliminate, the chance of testing positive".
4. Skip the high risk categories. Be most careful with products sold for bodybuilding, weight loss, energy, sexual enhancement, pain or sleep.
5. Read the whole label, and do not stop there. A label cannot show what was left off it. The NCAA warns: "Do not rely on this list to rule out any label ingredient". See our NCAA banned substances guide for every class.
6. Keep a record. Add the product to your stack in Varsity Stack, so you and your staff know what you take. Keep a photo of the lot number too. A lot (or batch) is one production run.

If you are a college athlete, your school can also send a label to Drug Free Sport AXIS. It is the only label review service the NCAA subscribes to.

Check your supplements with Varsity Stack

The easiest way to check a supplement before a test is the free Varsity Stack app. Scan it before you buy to see if it is certified, then add it to your stack so you and your staff know what you take.

Download the App

For coaches, sports dietitians and athletic trainers: the team dashboard shows every athlete's stack and whether each product is certified, so staff can review what athletes take before testing season.

Request access for your program

Varsity Stack does not laboratory test supplements, and certification lowers risk without removing it.