Supplements and their risks

Please note: The Supplement Check is no longer available

Do you take supplements such as protein shakes, pre-workout shakes, energy drinks, herbal remedies or vitamins?

Before you take any supplements, seek the advice of your doctor or sports dietician about whether you really need them, or whether changes to your diet or training programme could get better results instead.

Supplements continue to be a serious issue for New Zealand athletes. In the past few years a number of athletes have tested positive to prohibited substances believed to have been ingested through nutritional supplements. Each of those athletes faced a ban from all sport of up to four years.


  • As an athlete you are solely responsible for every substance in your body.
  • By taking a supplement, you accept the risk that it could contain a banned substance, and the possibility of a four-year ban.
  • DFSNZ or the World Anti-Doping Agency (WADA) does not approve or endorse ANY supplements.

DFSNZ recommends you consider the following information when making your decision:

No supplement is 100% safe, however batch tested products are the lowest risk. Be aware that batch tested supplements do not provide a guarantee against testing positive.
Supplements can be accidentally cross contaminated by other substances made in the same factory, or can be deliberately spiked by the company to ensure users get results.
Many supplements have inaccurate labelling. Ingredients can have more than 20 different names and not every version is listed on the label. Labels may also fail to list every ingredient or refer to “proprietary blends” where ingredients are not specified.
Many studies suggest there is little evidence that athletes need supplements given a well-balanced diet.

Educate yourself

Complete DFSNZ’s E-Learning Level One course, and stay up to date on new anti-doping issues with the E-Learning Level Two course.

For additional information, please visit these websites:

Australian Sports Anti-Doping Authority

US Anti-Doping Agency

UK Anti-Doping