The popular body-building supplement Craze contains a chemical that's similar to methamphetamine, according to researchers who've tested its ingredients.
Craze is marketed as "performance fuel" that provides "the ultimate in pre-workout power," but the research project stemmed from several failed urine drug tests by professional athletes after taking the supplement.
Craze, which is widely sold in the United States, tested positive for the methamphetamine analog N,a-diethyl-phenylethylamine (N,a-DEPEA), according to the report. Furthermore, the researchers noted that N,a-DEPEA is not listed on Craze's ingredient label.
"So I think they're playing with stimulants to try and find something that will get people juiced up, revved up to work out and make them feel better," said Dr. Pieter Cohen, an internist at Cambridge Health Alliance in Somerville, Mass., who has conducted extensive research on supplements and was involved in the report.
Cohen and his colleagues tested three samples in their report -- two purchased online and one from a store.
The report, released Monday in the Drug Testing and Analysis Journal, was conducted by researchers from the global public health organization NSF International, Harvard Medical School and the National Institute for Public Health and the Environment.
The researchers go as far as to call the compound "a potentially dangerous designer drug," but they admit that Craze's "effects in humans are entirely unknown" because no one has studied them.
Also cited in the report as a, "conflict of interest," is the fact that NSF International's clients include dietary supplement manufacturers.
An attorney for Driven Sports, which makes Craze, defended the product, telling ABC News that the researchers have it all wrong.
Driven Sports cites its own testing that found no methamphetamine-like chemical in their product.
The company's "conclusions regarding the safety and composition of Craze have not changed: The product is safe and effective," Driven Sports says.
Plenty of testimonials praising Craze can be found on YouTube and it received BodyBuilding.com's New Supplement of the Year award in 2012.
It's unclear what will become of the report results. But don't expect the U.S. government and the Food and Drug Administration to step in because supplements aren't treated like drugs.
"With supplements, it's really the wild, wild west," ABC News chief medical editor Dr. Richard Besser said. "There's no proof that they work and they only take them off the market if someone's been harmed."