Researchers Find Andro Produces Nandrolone Metabolite

November 27, 2000

2 Min Read
Researchers Find Andro Produces Nandrolone Metabolite

LOS ANGELES--In the Nov. 22/29 Journal of the American Medical Association (JAMA), researchers found that androstenedione (andro) and 19-norandrostenedione caused positive urine tests for 19-norandrosterone, a nandrolone metabolite and banned sports supplement.

In a randomly assigned seven-day study, 41 men between the ages of 20 and 44 were divided into three groups: one received 100 mg per day of oral andro, another received 300 mg and the third group received no andro. Additionally, four patients received 10 micrograms of 19-norandrostenedione. The authors, led by Dr. Don Catlin of the University of California Olympic Analytical Laboratory, found that all urine samples taken from the andro and 19-norandrostenedione groups contained 19-norandrosterone.

However, authors noted that if these samples were from competing athletes, 20 of 24 men would have tested over the Olympic Committee cutoff amount of 2 nanograms per milliliter of norandrosterone.

The authors also noted that of the seven brands of andro used, one contained no andro, one contained 10 mg of testosterone and four others contained 90 percent or less of the amount stated on the label. "This is a case where the buyer must beware," Catlin said in an interview to the Associated Press. "The only way to protect yourself from testing positive for steroid use is to not take drugs or health supplements at all."

However, Catlin may be painting an entire industry with an overly broad brushstroke. "What this study shows is that andro samples can potentially be 'contaminated' by other products that cause an athlete to test positive for nandrolone," said Conrad Earnest, Ph.D., program director of the Cooper Institute for Aerobics Research. He added that a manufacturer could have failed to adequately clean its machines following a run of 19-norandrostenedione prior to running androstenedione samples. "If you are a fan of conspiracy theories, the manufacturer could have purposely 'laced' its andro product with 19-nor. However, this theory is flawed because there is no research showing that 19-nor to be an effective training aid."

He concluded that researchers still don't know the benefits or risks associated with 19-norandrostenedione.

This study was funded by the National Football League (NFL), Major League Baseball (MLB), the Major League Baseball Players Association, the National Collegiate Athletic Association (NCAA), the U.S. Olympic Committee and the National Institutes of Health. However, the organizations did not participate in the design, conduct, interpretation or analysis of the study. For additional information, visit

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