Ethics CasesSport

Cases · Athletics · 2009–2025

Caster Semenya and Testosterone Eligibility Rules

South African runner Caster Semenya, the 2012 and 2016 Olympic 800m champion, has differences of sex development (DSD). World Athletics (formerly the IAAF) adopted regulations in 2018 requiring athletes with certain DSDs to lower their testosterone to compete internationally in the female category in events from 400m to the mile. Semenya refused medication and challenged the rules. CAS upheld the regulations in 2019, and the Swiss Federal Supreme Court dismissed her appeal in 2020. In 2023 a chamber of the European Court of Human Rights found that Switzerland had violated her rights. In July 2025 the court's Grand Chamber narrowed that ruling, finding only that she had been denied a sufficiently rigorous fair hearing.

Timeline

  1. Semenya wins the 800m world title at age 18 amid public controversy and sex testing.
  2. The IAAF announces its DSD regulations: testosterone must be kept below 5 nmol/L for restricted events (400m to the mile).
  3. CAS announces its decision rejecting Semenya's challenge. It finds the rules discriminatory but necessary and proportionate.
  4. The Swiss Federal Supreme Court dismisses her appeal.
  5. World Athletics tightens the rules: a lower testosterone limit (2.5 nmol/L), applied to all female events.
  6. A chamber of the European Court of Human Rights finds that Switzerland violated Semenya's rights under the European Convention on Human Rights.
  7. The Grand Chamber issues a final judgment. It finds a violation of the right to a fair hearing (Article 6) because the Swiss review was not rigorous enough, but it does not uphold the discrimination findings.

The ethical issues

  • Fairness in the female category versus inclusion and non-discrimination.
  • Bodily integrity and medical ethics: requiring medically unnecessary hormone suppression in order to compete.
  • Scientific uncertainty: how strong the evidence on testosterone and performance must be to justify exclusion.
  • Privacy and dignity: public speculation about an athlete's body.
  • Accountability of sports arbitration: the limits of court review of CAS awards.

Stakeholders

StakeholderInterests & obligations
Caster Semenya and athletes with DSDsThe right to compete, bodily autonomy, and dignity.
Other female athletesFair competition and clear eligibility rules.
World AthleticsProtecting the female category; legal defensibility.
CAS and national courtsLegal process and human rights standards.
Medical professionalsEthical obligations when treatment is not medically needed.

Why this case matters

Semenya’s case is central to debates over eligibility in women’s sport, testing how sport governance, science, medical ethics, and human rights law interact.

Discussion questions

  1. How should sport balance fairness in the female category against inclusion and non-discrimination?
  2. Is it ethical to require athletes to take medication they do not medically need in order to compete?
  3. What level of scientific evidence should be required before restricting eligibility?
  4. Should CAS awards receive more rigorous review by courts? What would change in practice?

Sources

  1. Semenya judgment of the Swiss Federal Supreme Court, Aug. 25, 2020 (unofficial English translation) — Centre for Human Rights, University of Pretoria
  2. Caster Semenya — Wikipedia