What is the thyrax? A drug to lose weight?

Presented as “a miracle product“which would promote weight loss and which would improve the physical performance of the riders, in particular the Tour de France 2023, the thyrax is a medicine that has caused a lot of ink to flow throughout the race. But what is it exactly? A doping product ? A medicine authorized in France? Presentation and risks.

What is the thyrax?

The thyrax is the trade name of the levothyroxine in the Netherlands (in France, levothyroxine is contained in Levothyrox®), an active substance normally indicated in treatment of hypothyroidism. In a healthy subject, levothyroxine would be “an accelerator of the body” and would have benefits on weight loss, this is why its use would be diverted by runners. “This product allows easily lose a few pounds and therefore to eat more. Normally, weight loss leads to loss of power, but with Thyraxyou can develop more watts per kilogram“, anonymously explains a runner, whose words were relayed by the Pharmacist’s Daily citing Dutch media Wielerflits. Indirectly it is a way to pedal faster because we are lighter. The riders would use it, not before the competitions, but during their training camps, during which they carry out intense physical preparation in order to be as efficient as possible in the race few weeks later.

Is it on the list of doping products?

No, levothyroxine, and therefore by extension the thyrax, does not appear in the decree of February 22, 1990 fixing the list of substances classified as narcotics. This medicine is not not prohibited for athletes. In some cases, runners would take levothyroxine in combination with cortisonea product banned by the World Anti-Doping Agency (WADA) during competition, but which can only be administered with a medical authorization for therapeutic use (TUE) (under conditions).

What is the composition of the thyrax?

Thyrax is a medicine that contains levothyroxine, a hormone that belongs to the family of thyroid hormones. It is mainly used as a substitute treatment to replace natural thyroxine when the latter is no longer secreted in sufficient quantity by thyroid.

Is it over-the-counter or on prescription?

Levothyroxine is only available on medical prescription (arrangement).

What are the dangers of thyrax?

Like all medicines, levothyroxine products, of which the thyrax is a part, can carry a risk of side effects such as:

• Possible aggravation of heart problems
• an allergic reaction
• Tachycardia
• Tremors
• Insomnia problems
• an excitability
• Fever
• sweats
• rapid weight loss
• Diarrhea…

In case of abuse or overdose, it may endanger life. According to the manager of the DSM team (Dutch cycling team), for several years many professional training courses have asked the International Cycling Union to take action regarding the use of this drug by cyclists.