A popular and widely used workout supplement, Craze, has been discovered to contain a substance similar to methamphetamine, according to new research from Harvard Medical School.

The substance, N,alpha-diethylphenylethylamine (N,alpha-DEPEA), which is not listed as an ingredient on the supplement’s label, has never been studied in humans, and little is known about its health effects.

Driven Sports, Inc., the producer of Craze, advertises the performance-enhancing supplement on its website as the “ultimate in pre-workout power.” Craze was named “New Supplement of the Year” in 2012 by bodybuilding.com but came under investigation after several athletes taking Craze failed urine drug tests.

The supplement’s label claims that it contains the substance N,N-Diethyl-Phenylethylamine (N,N-DEPEA), which is derived from dendrobium orchids and contains the same constituent atoms of the meth-like chemical N, alpha-DEPEA but arranged in a different structure and thus eliciting different properties.

“We didn’t find anything in dendrobium that should be a stimulant,” said Pieter A. Cohen, co-author of the study and assistant professor at Harvard Medical School.

The study, published online in the journal Drug Testing and Analysis on October 14, tested three samples of Craze purchased online and in a GNC vitamin and mineral store, and found 21 to 35 milligrams of N,alpha-DEPEA per manufacturer recommended serving of Craze. These tests were performed at NSF International in Michigan, a global independent public health and environmental organization, and confirmed by the Korean Forensic Service.

According to the paper, N, alpha-DEPEA is a “potentially dangerous designer drug” that has not been found in any plant, including dendrobium. The authors also claim that the amount of the substance in each serving rules out the possibility of minor contamination from the manufacturing process.

Because it has never been tested in humans, the health effects of N, alpha-DEPEA are largely unknown.

“It might act like a mild stimulant...and might cause some sense of euphoria,” Cohen said.

Driven Sports released a statement a day after the study was published, announcing that it had “suspended production and sale of Craze several months ago while it investigated the reports in the media regarding the safety of Craze.” The results of their own studies identified the presence of the substance N-beta DEPEA in Craze, which the company insists is a “very different substance” than N-alpha DEPEA.

The authors of the study contacted the FDA about their conclusions in May, but the FDA has yet to release an official public statement regarding the drug. Cohen said that the FDA should more actively screen supplements.

Other researchers echoed Cohen’s call for more FDA intervention.

Paul A. Offit, chief of the Division of Infectious Diseases at the Children’s Hospital of Philadelphia, asserted, “This isn’t the first time supplements are contaminated. It shows the problem with the dietary supplement industry—it’s essentially unregulated by the FDA.”