A team from ConsumerLab.com also found that products with unlisted banned substances are not limited to performance enhancers but include products ranging from multivitamins to sleep aids. The most common unlisted substances were stimulants such as ephedrine and caffeine.
This discovery is sure to send shockwaves through the supplement industry and could even give hope to athletes who have protested their innocence after being found guilty of taking a banned substance.
ConsumerLab.com's quality testing of nearly 1,000 supplements also revealed one out of four lacked the claimed ingredients. More disturbingly contaminants such as heavy metals, pesticides and manufacturing by-products were not only present but also failed to dissolve properly meaning that they could remain in the body.
Dr William Obermeyer, vice president for research at ConsumerLab.com was quick to point out special testing methods, such as those employed by ConsumerLab.com, should be used to detect low levels of banned substances. Standard laboratory tests often do not detect small amounts of banned substances that, if ingested, can trigger a positive urine test.
He warned though that supplements, particularly those coming from abroad and labeled as 'natural' may be intentionally spiked with unlabeled banned substances, such as stimulants, in order to cause a perceived boost in performance.
Obermeyer recommended that athletes familiarise themselves with the different supplement ingredients that may naturally contain a banned substance. Manufacturers should consider providing label information that identifies these ingredients.
Originally designed for the US Olympic Committee, ConsumerLab.com's Athletic Banned Substance Screening Program was the first comprehensive program to focus on supplements, as opposed to the downstream testing of body fluids from athletes.
The test was offered to manufacturers, sports associations, and players' associations. The program tests for up to 170 banned substances based on the World Anti-Doping Code Prohibited List and include stimulants, narcotics, anabolic agents, diuretics, masking agents, and beta-blockers.
A full report of the findings is available on the ConsumerLab website.