The International Olympic Committee (IOC) announced it will require a 'one-time' genetic screening for all female athletes wishing to compete in the Olympic Games, beginning with the 2028 Olympic Games in Los Angeles.
The IOC has adopted a policy similar to that imposed by the UCI, which limits eligibility to compete in any female category event to biological females, but goes a step further to impose a requirement for athletes to prove their sex through genetic testing.
The specific test detects the presence of the SRY gene, a Y-chromosome marker involved in male sex differentiation during embryonic development. Any athlete with an SRY-positive screen is no longer eligible for competition in the female category.
The IOC press release reads, "Athletes with an SRY-positive screen, including XY transgender and androgen-sensitive XY-DSD athletes, continue to be included in all other classifications for which they qualify. For example, they are eligible for any male category, including in a designated male slot within any mixed category, and any open category, or in sports and events that do not classify athletes by sex."
After the World Athletics Federation introduced SRY screening in 2025 ahead of the World Athletics Championships in Tokyo, the researcher who discovered the SRY gene, Professor Andrew Sinclair of the Murdoch Children's Research Institute, wrote an opinion piece objecting to using the SRY gene for this purpose.
"It is worth noting these tests are sensitive. If a male lab technician conducts the test, he can inadvertently contaminate it with a single skin cell and produce a false positive SRY result," Sinclair wrote.
"No guidance is given on how to conduct the test to reduce the risk of false results.
"Nor does World Athletics recognise the impacts a positive test result would have on a person, which can be more profound than exclusion from sport alone.
"There was no mention from World Athletics that appropriate genetic counselling should be provided, which is considered necessary prior to genetic testing and challenging to access in many lower- and middle-income countries."
The IOC press release states that a survey of 1,100 athletes and other consultations revealed, "a strong consensus that fairness and safety in the female category required clear, science-based eligibility rules, and that protecting the female category is a common priority".
The IOC also directed International Federations and National Olympic Committees to "ensure access to mental health and safeguarding support, provide clear early guidance on SRY gene screening and, where appropriate, align it with regular sports health checks. They should also maintain safe, accessible channels for information, concerns and reporting, with specific safeguards for minors".
They further clarified that the requirement for female athletes to be SRY negative: "It is not retroactive and does not apply to any grassroots or recreational sports programmes."
There is a "rare exception" to the ban for athletes "with a diagnosis of Complete Androgen Insensitivity Syndrome (CAIS) or other rare differences/disorders in sex development (DSDs) who do not benefit from the anabolic and/or performance-enhancing effects of testosterone".
IOC President Kirsty Coventry said, "As a former athlete, I passionately believe in the rights of all Olympians to take part in fair competition. The policy that we have announced is based on science and has been led by medical experts.
"At the Olympic Games, even the smallest margins can be the difference between victory and defeat. So, it is absolutely clear that it would not be fair for biological males to compete in the female category."
