SARMs were created by accident. In the early Nineties, a scientist named Professor James T Dalton was working on pioneering treatments for prostate cancer when he identified the molecule andarine – the first SARM. It was of little use in treating prostate cancer, but it had a remarkable effect on muscle growth. “It was the opposite of what we were looking for at the time,” he told Men’s Health. “But we turned almost all of our attention to this. We knew we really had something unique.”

Several years later, Dalton went on to create a more refined version, known as ostarine. In clinical trials, elderly men given a 12-week course of the drug increased lean muscle mass and reduced fat, while gaining more than a 15% improvement in stair climb power. But a subsequent trial in cancer patients failed to produce the desired results and the drug’s development halted. Dalton has since tried to curb the companies operating a black market for his discoveries. “We reached out with cease and desist letters to a couple of them, we reached out to the FDA to try shutting them down,” he says. “But it’s rampant and there’s really little that can be done to control it.”

What Are the Side Effects of SARMs?

The evidence here is largely anecdotal. On online forums, users report strength gains, but they also frequently seek advice about issues such as high blood pressure, skin rashes and impotence. Problems with eye-sight appear to be particularly common; andarine is reported to give users’ vision a green or yellow tinge.

Most of the available information online comes from sellers and YouTubers, so there’s a tendency for advice to skew positive. Dr Ian Boardley, a senior lecturer in sports psychology at Birmingham University, says: “If someone is using them themselves, it’s in their interest to believe they can use them safely. I think that’s happening with SARMs.” Even if users conduct significant amounts of research into their chosen substances, the conclusions they draw are not necessarily accurate. “One of the things we often see is the distortion and selective use of information to support their behaviour,” he explains. “It’s quite a dangerous process.”