Did you know that a lab test can determine whether anabolic steroids in urine were naturally made by the body or came from taking a prohibited substance?

How does the test do the trick?  “It measures the carbon isotope ratio of testosterone and other hormones in the urine… The measurement for pharmaceutical testosterone, which is made from plant steroids, is different from natural testosterone because the molecular carbon framework is put together differently by plants and humans.”*

Dr. Catlin helped develop and was the first to offer the carbon isotope ratio (CIR) test in the 1990s.

*From “CIR Foils Cheaters” by Caroline K. Hatton, Ph.D., published online by The National Center for Drug Free Sport, Inc., and one of the articles found here in Introduction to Selected Topics.