The International Olympic Committee has officially limited all women’s events to biological females. A mandatory genetic test will be required starting from the 2028 Los Angeles Games.
The IOC announced the decision on Thursday after a board meeting in Lausanne. It is one of the biggest eligibility changes in modern Olympic history.
Under the new rules, any athlete who wants to compete in a women’s event at the Olympics or other IOC competitions must pass an SRY gene screening.
The SRY gene sits on the Y chromosome and is key to male biological development. Athletes will only need to take the test once in their career.
The IOC also released a 10 page policy document that affects athletes with differences in sex development. This includes two time Olympic champion runner Caster Semenya from South Africa.
Semenya was assigned female at birth but has naturally high testosterone levels. She has fought a long legal battle over eligibility rules in track and field. A European Court of Human Rights ruling went in her favour but did not overturn those restrictions.
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The policy closely matches a directive signed by United States President Donald Trump in February 2025 that executive order threatened to pull funding from organisations that allowed transgender athletes to compete in women’s sport.
With the 2028 Games taking place on American soil, the political pressure on the IOC was strong. The US Olympic and Paralympic Committee had already told national federations they had to follow the White House order.
IOC President Kirsty Coventry, the first woman to lead the organisation in its 132 year history, made this review a priority soon after she took office in June 2025.
She set up a working group focused on protecting the female category. The issue also played a major role in the seven candidate IOC presidential election before her appointment.
The IOC’s research found that being born male gives physical advantages in strength, power and endurance. It also found those advantages stay even after medical transition. The expert group said the SRY gene test was the most accurate and least intrusive method available.
It is still unclear how many transgender women, if any are competing at an Olympic level right now. No transgender woman competed at the 2024 Paris Summer Games.
Weightlifter Laurel Hubbard from New Zealand was the first openly transgender athlete to compete at the Olympics in a different gender category from the one assigned at birth. She appeared at the Tokyo Games in 2021 but did not win a medal.
Taiwanese boxer Lin Yu-ting, one of two women’s boxing gold medallists at the centre of a gender controversy in Paris, recently passed the SRY gene test. The World Boxing governing body has cleared her to return to competition.
The new rules do not apply to past results and do not cover grassroots or recreational sport. Before this policy, the IOC had let individual sports federations set their own eligibility rules.
This created a mix of different standards across sports. Track and field, swimming and cycling had already stopped transgender women who went through male puberty from competing before the Paris Olympics.
The decision is expected to face criticism from human rights groups and advocacy organisations. More than 80 such groups had already spoken out against the proposals when they were first reported earlier this month.
The policy will now act as a single standard across all Olympic sports, putting an end to years of mixed rules and debate over how to balance inclusion with competitive fairness.
