Olympic Committee Bans Transgender Women and Most DSD Athletes from Female Events Starting 2028

The Decision

The International Olympic Committee announced Thursday that eligibility for female-category events at the Olympics and all other IOC events will be restricted to biological females, effective from the 2028 Los Angeles Summer Games. The policy applies to both individual and team sports.

Under the new rules, athletes must test negative for the SRY gene — the sex-determining region Y gene, a segment of DNA typically found on the Y chromosome that initiates male sex development. The test, conducted via saliva, cheek swab, or blood sample, will be administered once per career. Athletes who pass are permanently eligible; those who fail are barred from the female category but may compete in male, mixed, or open categories where those exist.

"Eligibility for any female category event at the Olympic Games or any other IOC event, including individual and team sports, is now limited to biological females," the IOC said in a 10-page policy document published Thursday.

What IOC President Coventry Said

IOC President Kirsty Coventry — a two-time Olympic gold medalist in swimming who became the first woman to lead the Olympic body in its 132-year history — framed the decision as grounded in science and athletic fairness.

"At the Olympic Games, even the smallest margins can be the difference between victory and defeat," Coventry said in a statement. "So, it is absolutely clear that it would not be fair for biological males to compete in the female category. In addition, in some sports it would simply not be safe."

"Every athlete must be treated with dignity and respect, and athletes will need to be screened only once in their lifetime," she added. She said the policy was developed through a working group of medical experts and athlete consultations, and emphasized it was "a priority for me way before President Trump came into his second term. There's not been any pressure on us to deliver anything from anybody outside of the Olympic Movement."

The Science Behind the Policy

The IOC's 10-page document details its research on sex-based performance differences. According to the IOC's working group findings:

• There is a 10–12% male performance advantage in most running and swimming events.
• There is a 20% or greater male performance advantage in most throwing and jumping events.
• The male performance advantage "can be greater than 100%" in events involving explosive power, including collision, lifting, and punching sports.

The IOC said males experience three significant testosterone peaks — in utero, in mini-puberty of infancy, and beginning in adolescent puberty through adulthood — and that these "provide individual sex-based performance advantages in sports and events that rely on strength, power and/or endurance."

The document states that "XY transgender athletes and athletes with XY-DSD typically have testes/testicles and testosterone levels in the male range. The clear majority are androgen-sensitive, meaning that their bodies are receptive to and make use of that testosterone during growth and development and throughout their athletic career."

The IOC said its working group reviewed the latest scientific evidence over 18 months and found "clear consensus" that "male sex provides a performance advantage in all sports and events that rely on strength, power and endurance." The group consulted "a wide range of experts in relevant fields" and conducted an online athlete survey with more than 1,100 responses, as well as individual interviews with affected athletes.

Who Is Affected

Transgender women: Athletes who transitioned from male to female are now excluded from the female category regardless of hormone therapy status or testosterone levels. New Zealand's Laurel Hubbard, who became the first openly transgender woman to compete at an Olympics at Tokyo 2020 (without winning a medal), would not be eligible under the new rules. No transgender women were known to have competed in the female section at the 2024 Paris Games.

DSD athletes: Athletes with differences in sex development (DSD) — conditions in which a person's hormones, genes, or reproductive organs may be a mix of male and female characteristics — are also largely excluded if they have gone through male puberty. This directly affects South African runner Caster Semenya, the two-time Olympic women's 800m champion (London 2012 and Rio 2016), who has male XY chromosomes and has been in a years-long legal dispute with track and field's governing body over its own testosterone restrictions.

There is one exemption: athletes with complete androgen insensitivity syndrome (CAIS) are still eligible, because that condition means they have not gone through male puberty despite having XY chromosomes.

Imane Khelif: The Algerian boxer who won gold in the women's 66kg category at Paris 2024 amid controversy over an IBA disqualification from the World Championships told CNN earlier this year she would take a sex test to compete at LA 2028. World Boxing said last week that Taiwan's Lin Yu-ting, the other women's boxing gold medalist at the center of the Paris controversy, has already passed her gene test and can return to competition.

Context: A Policy Shift Years in the Making

Until Thursday, the IOC had left sex eligibility regulations to the governing bodies of individual sports rather than applying a universal standard. That produced a patchwork: track and field, swimming, cycling, and rowing had introduced sweeping bans on transgender women who had been through male puberty, while many other sports still allowed competition provided athletes kept testosterone within certain levels.

The IOC used SRY gene testing in the 1980s but abandoned it in the 1990s after a number of false positives and concerns that female athletes were being penalized for natural biological variations. Sports governing bodies then moved to testosterone-level thresholds as the primary eligibility criterion.

The debate intensified after the 2024 Paris boxing controversy and a broader political environment that included President Donald Trump signing an executive order titled "Keeping Men Out of Women's Sports" in February 2025, pledging to deny visas to some athletes attempting to compete at the LA Olympics and threatening to "rescind all funds" from organizations permitting transgender athletes in women's sports. The U.S. Olympic and Paralympic Committee updated its guidance to national sports bodies in the months that followed, citing an obligation to comply with the White House.

Coventry, who set up the female eligibility review as one of her first acts after being elected IOC president in June 2025, said it was a commitment she made before Trump's election, and that no external pressure drove the timetable.

According to a September report cited by The Guardian, between 50 and 60 athletes who went through male puberty had been finalists in the female category in global and continental track and field championships since 2000.

Reactions

The charity Sex Matters welcomed the ruling. "We wholeheartedly welcome the new IOC guidelines that secure a safe and fair female category," said Emma Hilton, the group's interim chair. "SRY screening is a simple, non-invasive, once-in-a-lifetime check that returns female sport to female athletes."

The charity Dsdfamilies expressed concern about the impact on DSD athletes specifically. "Fairness in competition is important, but eligibility rules must also be proportionate and aligned with contemporary standards of DSD care, rather than creating foreseeable and avoidable harm to this vulnerable minority group," spokesperson Ellie Magritte said. "We are concerned that proposed processes do not always demonstrate the level of understanding, dignity, and respect that this issue requires."

This month, a group of academics submitted a report to the British Journal of Sports Medicine calling sex testing "a backwards step and a harmful anachronism," arguing it violates the human rights of athletes and "is a simplistic way of reducing a characteristic to a single gene, which does not reflect the complex nature of sex."

Ronit Stahl, a historian at the University of California at Berkeley and author of Enlisting Faith: How the Military Chaplaincy Shaped Religion and State in Modern America, was not among the directly involved experts but represents the broader academic critique that single-gene screening oversimplifies a complex biological landscape.

Legal Challenges Likely

The IOC acknowledged the policy could be challenged at the Court of Arbitration for Sport, the Olympic body's dispute resolution tribunal based in Lausanne, Switzerland. Previous eligibility rules in track and field were challenged at CAS by Indian sprinter Dutee Chand and by Caster Semenya. Coventry said: "As we know in today's world, any and all rules and regulations at any point in time could always be challenged."

The policy is not retroactive and does not apply to any grassroots or recreational sports programs. It takes effect from the 2028 Los Angeles Summer Olympics, which opens in July 2028.