Specialist doctor provides concrete information on Clostebol amid Jannik Sinner’s doping saga

Jannik Sinner will complete his three-month WADA ban in May and is scheduled to mark his return at the Rome Masters.

Specialist doctor provides concrete information on Clostebol amid Jannik Sinner’s doping saga

Jannik Sinner (Image via X)

World No. 1 Jannik Sinner is currently serving a three-month ban from WADA. The Italian tested positive for clostebol, a banned substance, during his Indian Wells campaign last year. Last month, he was handed a three-month suspension by the tennis authorities.

Clostebol has been under intense scrutiny since the controversy. Jean-Pierre de Mondenard, a specialist doctor in this field, has provided insights into the effects of clostebol and its impact on Sinner’s body.

The transdermal route (through the skin) is precisely adapted to doping with anabolic steroids because a large part remains in the fats for a certain time. This is what the US Postal, Sky and … teams understood in order to escape the anti-doping radars. A German specialist anti-doping expert comes to the same conclusions as JPDM. Clostebol was found during a urine test but this cannot provide precise information on the dose actually applied to Jannik Sinner’s skin.

Jean‐Pierre de Mondenard said on X

Sinner’s positive doping test was confirmed in August, shortly after his Cincinnati Open win. As a result, his prize money and ranking points were deducted from his Indian Wells performance. He had lost in the semifinals to Carlos Alcaraz at the BNP Paribas Open last year.

Despite the three-month ban, Sinner is eligible to play in all the Grand Slam tournaments in 2025. This has led to intense criticism of the tennis authorities, especially from Australian tennis star Nick Kyrgios.

Jannik Sinner handed huge ranking boost

Alexander Zverev‘s struggles continued as he lost to Tallon Griekspoor in his first match at the Indian Wells Masters. This defeat was a big help to world No. 1 Jannik Sinner, who is not playing in the tournament.

Jannik Sinner Australian Open 2025
Jannik Sinner (via Instagram)

Sinner is missing the Indian Wells and Miami Masters because he got a three-month ban. He tested positive for the anabolic steroid clostebol nearly a year ago. He proved that he was not at fault, and the International Tennis Integrity Agency cleared him of any wrongdoing.

The World Anti-Doping Agency appealed that decision. They wanted a one-year ban but later agreed to a three-month suspension. This has kept Sinner out of two major tournaments, giving Zverev a chance to close the ranking gap.

Zverev had recently struggled with food poisoning during matches on clay courts in South America. He hoped to do better on the hard courts at Indian Wells. However, Griekspoor, who had beaten Daniil Medvedev in Dubai, won against Zverev in a tough match. This loss leaves Zverev more than 4,000 points behind Sinner and gives Carlos Alcaraz a chance to catch up.