The IOC has ruled that only biological females can compete in women’s Olympic sport from 2028, using a one-time SRY gene test. The decision follows scientific review and consultation but has drawn mixed reactions from athletes and organizations. The policy marks a major shift in Olympic eligibility rules and will take effect at the Los Angeles Games.
The International Olympic Committee has announced that women’s sport at the Olympic Games will be limited to biological females starting from the 2028 Games in Los Angeles. The decision follows a vote and policy review and introduces a single, lifetime sex test to determine eligibility for the female category.
The policy was confirmed by IOC president Kirsty Coventry, who said the rule was developed after a review led by medical experts. She stated that even small differences can affect outcomes in elite sport and said the change is intended to ensure fairness and safety in competition.
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Under the new rule, eligibility for the women’s category will be based on screening for the SRY gene, which is linked to the Y chromosome and the development of male characteristics. The IOC said the test can be conducted using saliva, a cheek swab, or a blood sample, and described it as less intrusive than other methods.
Athletes who do not meet the criteria will not be excluded from sport entirely. The IOC said those athletes will still be able to compete in male categories, mixed events, or open categories, depending on the sport. The organization also confirmed that athletes will only need to take the test once in their lifetime.
The decision marks a change in IOC policy. Previously, the committee allowed individual sports federations to set their own eligibility rules. Some sports, including athletics, swimming, cycling, and rowing, had already restricted participation for transgender women who had undergone male puberty, while others allowed participation based on reduced testosterone levels.
The issue has been part of ongoing discussion in recent years. At the Tokyo 2020 Olympics, New Zealand weightlifter Laurel Hubbard became the first openly transgender woman to compete in the Games. However, by the Paris 2024 Olympics, there were no known transgender women competing in female events.
Attention also focused on boxing at the Paris Games, where Algeria’s Imane Khelif won the women’s welterweight gold medal. The win came after she had previously been disqualified from the World Championships for reportedly failing a gender eligibility test. Some reports suggested the presence of XY chromosomes, although this was not confirmed. Khelif has stated she is a woman and has said she would take a sex test to compete in 2028.
The new IOC policy will also apply to most athletes with differences of sexual development, commonly known as DSD. This includes athletes such as South Africa’s Caster Semenya, a two-time Olympic champion whose condition involves XY chromosomes. In the past, DSD athletes were allowed to compete in women’s sport if they maintained testosterone levels within set limits.
The IOC noted one exception for athletes with complete androgen insensitivity syndrome, or CAIS, a rare condition in which individuals do not experience male puberty. These athletes may still be eligible for the women’s category under the new rules.
The committee said its decision followed an 18-month review of scientific research and consultation with experts, athletes, and stakeholders. According to the IOC, the findings showed a consensus that male biological characteristics can provide a performance advantage in sports involving strength, speed, and endurance.
Reactions to the decision have varied. A spokesperson for World Athletics said the move supports fairness and a level playing field for women in sport. Campaign groups such as Sex Matters and SEEN in Sport also welcomed the decision, saying it protects opportunities for female athletes.
However, some athletes and organizations have raised concerns. Semenya criticized the policy, saying it does not reflect science and could lead to stigma. Stonewall said the decision may increase division and affect participation in sport at all levels.
Academic experts have also questioned the approach. Professor Alun Williams said genetic testing may not be necessary to regulate participation and warned that the policy could disproportionately affect certain athletes.
The IOC stated that the rule will not apply to grassroots or recreational sport and that test results will not be used retrospectively. Coventry added that athletes should be treated with dignity and respect and that support, including counselling and medical advice, will be provided throughout the process.
As the 2028 Olympics approach, the new rule is expected to shape participation in women’s sport and could lead to further debate or legal challenges. The IOC’s decision represents a significant change in how eligibility for female competition is defined at the global level.
