It goes by the name "Craze." Researchers at Harvard say that some of the ingredients in the supplement are being created in clandestine laboratories.
However, an attorney for the company that makes Craze says there is proof from a certified DEA lab showing there is no amphetamine-like compound in it.
Officials with the USDA cannot currently be reached for comment because of the federal government shutdown.
The findings are published in the journal "Drug Testing and Analysis."
