Stanozolol, also known as Winstrol, seems to be the anabolic steroid of choice for competitive athletes around the world in 2015. At the very least, it seems to be the steroid that is coming up hot in urine samples collected by anti-doping officials. In a three-week span beginning on March 20, 2015, a total of 15 athletes have been suspended after testing positive for stanozolol.

Major League Baseball (MLB) made the announcement that three pitchers from three different teams each tested positive for the very same performance-enhancing drug (PED) during the off-season. Minnesota Twins Ervin Santana, Atlanta Braves Arodys Vizcaino and Seattle Mariners David Rollins were suspended for 80-games without pay thanks to stanozolol.

The rash of stanozolol positives was not limited to North America. Just a few days earlier across the pond in Europe, the Bulgarian Weightlifting Federation announced that eleven Bulgarian Olympic weightlifters tested positive for stanozolol while they were preparing for the 2015 European Weightlifting Championships. The steroid positives included the 2014 European champions Ivan Markov and Ivaylo Filey and the 2005 European champion Demir Demirev. These three could face a lifetime suspension since it was their second failed anti-doping test.

And then the purge of Winstrol-using athletes moved to South America. The Brazilian MMA Athletic Commission (CABMMA) suspended UFC lightweight fighter Jorge Oliveira after he failed the post-fight drug test at UFC Fight Night 62.

The big question is ‘why are so many athletes testing positive for stanozolol?’

Unfortunately, as is typically the case, we are not getting any assistance from the athletes involved.

Only one athlete admitted using stanozolol. The Mariner’s Rollins admitted he made a “mistake” using the steroid. Most of the others could not explain how stanozolol ended up in their urine samples.

The Twins’ Santana proclaimed his ignorance at providing an explanation for the steroid positive test result.

“I am very disappointed that I tested positive for a performance-enhancing drug,” Santana said in a statement. “I am frustrated that I can’t pinpoint how the substance in question entered my body.

Bulgarian national team coach Ivan Ivanov seemed genuinely “shocked” to learn that the lifters tested positive for stanozolol.

“I’m shocked,” said Ivanov. “Stanozolol is an archaic substance in weightlifting, no one is using it. My only explanation of its presence in the bodies of the weightlifters is that they had taken it through the food additives we are using for recovery.”

Coach Ivanov is correct in stating that stanozolol is an “archaic” drug. Stanozolol was introduced over 50 years ago. It has been marketed for human use for decades under the trade names Winstrol Depot (injectable stanozolol) and Winstrol Tablets (oral stanozolol). It became one of the sporting world’s most notorious anabolic steroids after sprinter Ben Johnson tested positive for it at the 1988 Seoul Summer Olympics.

This didn’t necessarily lead athletes to stop using it. If they were able to successfully use this infamous steroid in a manner in which they could avoid detection, then they most certainly would have continued using it. But if anti-doping laboratories gained access to a testing procedure that performed a better job at detecting stanozolol metabolites, steroids and patterns of steroid use that were previously undetectable could very well have become detectable practically overnight.

This could be the most likely explanation for the surprising high number of stanozolol positives.

A 2013 breakthrough in anti-doping technology reported an increase in the detection window for stanozolol to over six months. This new steroid detection technology was jointly introduced by German and Russian anti-doping laboratories. The new testing procedure was found to be significantly more sensitive at detecting trace amount of stanozolol metabolites.

Athletes, who may have known exactly how many days were required to discontinue the use of steroids to avoid a positive steroid test result, were left at the mercy of anti-doping officials. Score one for the “cats” in this ongoing “cat-and-mouse game”.