A popular diet supplement advertised as giving “unrelenting energy and focus” during workouts has been found to contain a chemical substance similar to methamphetamine. According to USA Today, scientists in the United States and South Korea conducted tests on Craze, a pre-workout powder made by Driven Sports in New York, and the results were troubling.

Craze was discovered to have a substance called N,alpha-diethylphenylethylamine (N,alpha-DEPEA), which, according to a press release, is “likely less potent than methamphetamine but greater than ephedrine.” The substance isn’t listed on Craze’s label.

“Alarmingly, we have found a drug in a mainstream sports supplement that has never been studied in humans,” says Dr. Pieter Cohen, an assistant professor of medicine at Harvard Medical School noted for his experience researching and testing supplements. “The health risk of using supplements adulterated with a drug should not be underestimated.”

Scientists also found N,alpha-DEPEA in Detonate, a weight-loss supplement by Gaspari Nutrition.

"These are basically brand-new drugs that are being designed in clandestine laboratories where there's absolutely no guarantee of quality control," Cohen told USA Today. “Yes, it might make you feel better or have you more pumped up in your workout, but the risks you might be putting your body under of heart attack and stroke are completely unknown."

In the wake of the discovery, Walmart.com and other online retailers have stopped selling Craze, but the supplement is still available in GNC stores and some places online, USA Today pointed out.

“We urge consumers to remain vigilant about the dietary supplement products they choose, especially since products including Craze and Detonate are available in stores and online, and encourage them to look for certification as a sign that the product has been tested and certified to be free of undeclared ingredients or harmful levels of contaminants,” said Ed Wyszumiala, general manager of NSF International’s Dietary Supplement Certification Program.

Craze was voted “New Supplement of the Year” for 2012 by Bodybuilding.com, according to USA Today.

"We have previously provided USA Today with a plethora of data from a DEA-certified Lab indicating the absence of any amphetamine-like compound in Craze," Marc Ullman, an attorney for Driven Sports, said in an e-mail to USA Today. "In light of USA Today's decision to ignore the data we have provided, we respectfully decline to comment."

This isn’t the first time Driven Sports has landed in hot water. A separate USA Today investigation revealed that Matt Cahill -- a top executive at Driven Sports – has been busted in the past for conspiracy to commit mail fraud and introduction of a misbranded drug into interstate commerce.