"With Thyrax you actually get more watts per kilogram" - Reports surge regarding use of unbanned thyroid hormone 'Thyrax'

Within the world of cycling, the battle against doping and substances harmful to the performance of athletes is constant. Simultaneously, the search for performance by all means continues on part of riders and teams, and reports of the use of Thyrax have recently surged and can be a cause for concern.

Wielerflits has conducted an investigation into the matter, and were told by a rider in the peloton that “this product makes it easy to lose a few kilograms and you can therefore eat more. Normally body loss means less power. With Thyrax you actually get more watts per kilogram.”

Thyrax is a thyroid hormone that can be prescribed and legally used by athletes, as it is not currently banned under the sport's anti-doping agencies. As many other substances do however, it's abuse can lead to serious health complications. It is a grey area which is seemingly being used within the bunch as riders confined to the Dutch news outlet during the Opening Weekend, with reported weight loss as a "benefit" - for performance purposes alone.

Ralph Moorman, health coach and writer has mentioned that "along with cortisone is a winning combination. This certainly leads to better sports performance." Apparently, that knowledge has already been spreading through the peloton, although it is unclear which teams or riders may have the upper hand.

“We suspect that Thyrax is still used today as a means to improve top sports performance. Various studies are underway to determine whether thyroid hormone is an effective performance-enhancing agent," Peter Van Eenoo, director of the DoCoLab Gent, has also added to the argument. "It is not yet possible to give an unequivocal answer to this question. Some studies say that the benefits outweigh the drawbacks, while other studies clearly endorse an improvement in elite sports performance.”

Jumbo-Visma manager Richard Plugge stated the team wasn't involved in the rumours: "I think it's more of an old story. I don't bury my head in the sand, but recently I haven't heard any rumors about this in relation to cycling," he told. “This drug is not used by anyone in our country. We as a team adhere to our own protocol, which is equal to the protocol of Team NL. Thyrax is a medicine and to use a medicine you need a medical indication from a doctor. We are strongly against the misuse of medicines. It is therefore good that this is monitored and that it is addressed. As a sport, let's stay far away from that.”

The rumours first emerged back in 2018 but it was not possible to ban the substance as it was not yet possible to trace it, also with the current situation where it is not proven that the substance leads to performance enhancement. Now, five years later, a method has been created to detect it, and it is likely that it won't be long until more is head regarding the subject as it may be banned from competition.