IOC Mandates SRY Gene Screening for Female Category Eligibility Starting at LA28

For decades, elite sports have struggled to balance inclusion with fairness, resulting in a patchwork of confusing, sport-by-sport hormone regulations. The tension between protecting the female category and accommodating biological diversity has been one of the most fiercely debated issues in modern athletics. Now, the International Olympic Committee has moved to resolve this tension with a definitive, universal rule.[1][5]

On March 26, 2026, the IOC announced that starting at the Los Angeles 2028 Games, eligibility for the female category in all sports will be determined by a single, once-in-a-lifetime SRY gene screening. The policy applies to all individual and team sports on the Olympic program and replaces the previous framework that allowed international federations to set their own criteria.[1][2][5]

The SRY, or Sex-determining Region Y, gene is typically found on the Y chromosome. In utero, this gene acts as a master switch, initiating male sex development by triggering the formation of testes and the subsequent production of hormones like testosterone. For athletes and coaches trying to understand the science, the mechanism is straightforward: these hormones guide the body to develop male biological characteristics, which sports scientists note provide baseline advantages in strength, power, and endurance.[1][2]

Under the new policy, athletes who screen negative for the SRY gene via a simple, non-invasive cheek swab or blood test are permanently eligible to compete in the female category. The IOC stated that this genetic marker is fixed throughout life, making it a highly accurate and unintrusive method of verifying biological sex. For athletes, this means an end to the anxiety of continuous hormone monitoring; a single test provides lifetime clarity.[5]

Athletes who screen positive for the SRY gene will be ineligible for the female category, effectively banning transgender women and some athletes with differences in sex development from these events. The policy includes a narrow exception for individuals diagnosed with Complete Androgen Insensitivity Syndrome (CAIS)—a rare condition where the body possesses the SRY gene but cannot process testosterone, meaning the athlete gains no anabolic or performance-enhancing effects.[1][2][3]

This shift is particularly significant for martial arts and combat sports. The IOC explicitly cited safety in contact sports as a primary driver for the new mandate. In disciplines like judo, boxing, and taekwondo, the skeletal and muscular advantages gained during male puberty present direct physical risks to opponents, making a strict biological standard a matter of athlete welfare.[2]

The new mandate marks a sharp departure from the IOC's 2021 framework, which had instructed individual sports federations to create their own rules. That previous approach largely relied on suppressing circulating testosterone levels. However, recent sports medicine studies presented to the IOC indicated that testosterone reduction treatments do not fully reverse the physical advantages acquired during male development.[1][2][5]

The policy has drawn sharply divided reactions. Proponents, including IOC President Kirsty Coventry, argue that at the Olympic level, even the smallest margins dictate victory, making it fundamentally unfair for biological males to compete in the female category. They view the single genetic test as a clear, science-based standard that protects female athletes.[5]

Conversely, critics and human rights organizations argue that the test oversimplifies human biology. Geneticists point out that the mere presence of the SRY gene does not dictate how it functions, honestly flagging the uncertainty around complex genetic variations. Advocacy groups warn that the policy unfairly targets athletes with differences in sex development who do not possess a physiological advantage, emphasizing that biology is rarely a perfect binary.[4]

To understand the stakes of this regulatory shift, sports scientists and legal experts are analyzing the trade-offs of the two models that have defined this debate: the new universal genetic screen versus the previous sport-by-sport hormone threshold.[3][4]