Caster Semenya runs in the women’s 800m race during the Weltklasse IAAF Diamond League international athletics meeting in Zurich, Switzerland, August 30, 2018. (EPA-EFE/JEAN-CHRISTOPHE BOTT)

By Veronica Allan

Caster Semenya will have to take hormone-reducing drugs if she wants to continue her stellar international track career.

The South African sprinter, a double Olympic champion in the 800 meters, lost her case at the Court of Arbitration for Sport (CAS) — the highest court for sport-related disputes — in a decision released on May 1.

The decision means that women runners with high levels of the male sex hormone, which can increase size, speed and power, will have to take medication if they want to compete over certain distances.

Ironically, that means that some female athletes, barred like all athletes from taking performance-enhancing drugs, will now be required to take performance-diminishing medication.

The court ruling could have implications for other women’s sports, such as weightlifting, boxing, swimming and soccer, where high levels of testosterone can make a difference.

Are the rules discriminatory or necessary?

Semenya has hyperandrogenism, a medical condition that involves higher-than-typical levels of testosterone. Alongside the national governing body for her sport, Athletics South Africa, she challenged the International Amateur Athletics Federation (IAAF) over new rules that would limit testosterone levels for female and intersex athletes in events from the 400-meter to the mile.

The IAAF contends that elevated testosterone — an important sex hormone for males that is also found in females — provides a performance advantage for women in these events. Approximately seven out of every 1000 elite female athletes have hyperandrogenism, a rate much higher than in the general population.

Semenya’s legal team argued that the new rules were discriminatory and contribute to the surveillance and judging of women’s bodies — practices that have “historically haunted women’s sports.”

The court found that the new regulations are discriminatory but held that “such discrimination is a necessary, reasonable and proportionate means” of preserving the integrity of female participation in the specified events.

To comply with the regulations, Semenya and other athletes with differences of sexual development who identify as women — including her 800m rival from Burundi, Francine Niyonsaba — will be required to lower their testosterone levels through medical intervention, such as the use of hormonal contraceptives.

Tests on women are nothing new.

Hormonal contraceptives can produce a range of potential side effects, including headaches, weight gain and increased risk of blood clots.

For many of these athletes, it’s a lose-lose scenario: They either submit to unnecessary medical treatment, change sporting events or quit the sport altogether.

Despite pushback from athletes and experts, gender verification tests and efforts to regulate the bodies of female athletes are nothing new. Olympic officials have been conducting tests on women deemed “too masculine” for nearly 100 years.

In the 1940s, the International Olympic Committee (IOC) began requiring a doctor’s note to confirm the sex of female competitors.

The first call for mandatory sex testing came from the IAAF in 1966. Commonly referred to as the “nude parade,” women were required to display their naked bodies for a panel of doctors to examine them.

Then, from 1968 to 1998 the IOC used random genetic testing to verify the gender of female athletes.

For a little over a decade in the early 2000s, neither the IOC nor the IAAF mandatorily tested or regulated the sex of athletes who identified as women.

The IAAF’s findings have been controversial.

That came to an end in 2011 when the IAAF introduced its first rules to limit naturally occurring testosterone in female competitors. The rules came in response to questions about Semenya’s gender that surfaced after she won the 800-meter world title at the age of 18.

While some athletes left the sport and others began taking hormone-suppressing drugs, at least four young women underwent surgery to remove internal testes.

The IAAF’s original testosterone regulations were suspended in 2015 after the CAS ruled in favour of Indian sprinter Dutee Chand, who, like Semenya, had appealed the regulations on the basis of discrimination. The IAAF was given two years to produce evidence that testosterone confers a performance advantage for female athletes.

The IAAF did so, but its findings have been controversial.

After analyzing data from the 2011 and 2013 world track and field championships, IAAF researchers published a study showing that females with high levels of testosterone have a 1.8 to 4.5 percent advantage over females with lower levels of testosterone in certain events.

The court’s decision may not be set in stone.

Independent researchers found problems in up to one third of the data. In some cases, duplicate times were entered for the same athlete, and in others, there was no performance on record that corresponded to the time in the dataset.

The IAAF has acknowledged these errors, but remains “confident of the legal, scientific, and ethical bases for the regulations.”

Although the CAS has ruled, its decision may not be set in stone. In a 165-page document, the panel noted several concerns with the practical application of the IAAF’s regulations, including the need to consider further evidence linked to the side effects of hormonal treatment.

A lack of evidence supporting a testosterone-related advantage for women in the 1500m and the mile also led the panel to recommend that these events be exempt from the regulations.

Semenya’s case is only the latest in a long debate over what it means to be a woman in sport. And although she lost her fight, the battle is far from over.


  1. On what basis did Semenya challenge the rules limiting testosterone levels? Did the court agree with her argument?
  2. Why does the IAAF test and regulate testosterone levels? Do you think its ends justify the means? If not, what alternative methods to ensuring a level playing field would you propose?
  3. Do you see hormone testing as different from testing athletes for performance-enhancing drugs? Why or why not?

Veronica AllanVeronica Allan is a postdoctoral researcher in the School of Kinesiology and Health Science at York University and a journalism fellow in the Munk School of Global Affairs and Public Policy at the University of Toronto in Toronto, Canada. She researches and reports on athlete issues in youth and disability sport.

Share This
SportsTestosterone-heavy female runners face difficult choice