Conor McGregor, the prominent Ultimate Fighting Championship (U.F.C.) star, is preparing for a highly anticipated return to the octagon nearly three years after sustaining a severe leg injury during a bout in Las Vegas in July 2021. McGregor suffered a complex fracture to his left tibia and fibula when he broke his leg in a high-profile fight against Dustin Poirier, an injury that initially cast serious doubts on his ability to compete again.

Following extensive surgical repairs led by renowned orthopedic surgeon Neal ElAttrache, McGregor’s recovery has been described as remarkable. ElAttrache, known for treating a range of elite athletes and celebrities, was involved in the initial surgery and later recommended consultations with specialists in bone healing. While ElAttrache stated that he did not prescribe hormone or steroid treatments—substances banned under major sports antidoping regulations—he supported McGregor’s application for a therapeutic use exemption (TUE) that would have permitted the use of performance-enhancing drugs (PEDs) under medical supervision. The exemption, intended to allow athletes to use banned substances for legitimate medical conditions, was never granted.

Two individuals with direct knowledge of the matter said McGregor did take banned substances during his recovery with the backing of ElAttrache, who later clarified that he advised McGregor to comply with the U.F.C.’s drug-testing protocols regarding any treatments prescribed by specialists. The U.F.C. and the United States Anti-Doping Agency (USADA), which managed the U.F.C.’s antidoping program from 2015 until the end of 2023, viewed the TUE request with skepticism, interpreting it as an attempt to exploit a loophole to use PEDs. McGregor subsequently withdrew from the USADA testing pool in 2022, a move that led to a period during which he was not subject to drug tests. This absence, combined with his notable physical transformation, fueled widespread speculation among fans, fellow fighters, and commentators about potential doping.

McGregor’s management denied any direct use of PEDs and emphasized the severity of his injury, highlighting the difficulty of his recovery and the rigorous medical care he received. Audie Attar, McGregor’s manager, characterized public disclosures of his client’s medical history as a breach of privacy protections. Meanwhile, U.F.C. representatives stated that McGregor maintained communication and complied with the organization’s drug program.

Tensions between the U.F.C. and USADA escalated over McGregor’s eligibility to compete, particularly due to USADA’s requirement that returning fighters remain in the testing pool for six months before being cleared to fight. McGregor reportedly re-entered testing in October 2023 after disclosing his use of banned substances during his time outside the pool. Shortly thereafter, the U.F.C. announced it would not renew its contract with USADA, asserting that the agency’s handling of the McGregor situation was unsatisfactory.

The U.F.C. has since taken over its own antidoping program. McGregor was scheduled to fight Michael Chandler in June 2024, but the event was postponed due to an injury McGregor sustained while training. Following missed drug tests in 2024 and early 2025, the U.F.C. suspended McGregor for 18 months for violations of its testing rules. The suspension, backdated to account for injury recovery, is set to expire in time for McGregor’s planned return fight this month in Las Vegas, the same city where his injury originally occurred.

The controversy surrounding McGregor’s recovery and use of banned substances highlights ongoing challenges in balancing athlete health, fair competition, and the enforcement of antidoping regulations within high-profile sports organizations.