The Athletics Integrity Unit has provisionally suspended Andrej Hladnik of Croatia. He tested positive for the banned performance-enhancing drug ostarine.

The 25-year-old 2:25:38 marathon runner ran all of his 10K, half-marathon and marathons domestically, mostly in Zagreb or Zaprešić, Croatia.
The AIU published notification of his notification on January 13, however, he was initially informed in November of 2024.
What is ostarine
According to WebMD, Ostarine is a type of drug called a selective androgen receptor modulator (SARM). The FDA does not approve it in the US or HALMED in Croatia but is sometimes found in supplements.
Ostarine attaches to proteins in the body known as androgen receptors. When ostarine binds to these receptors, it tells muscles to grow.