If the latest outcome of legal tussles stands, South African Olympic gold medallist Caster Semenya will not be allowed to compete in the races in which she excels unless she undergoes medical interventions — pills, injections or surgery — to lower her natural levels of testosterone. Semenya, a cisgender woman who was assigned female at birth, was raised female and has always participated in sport as a woman, has for a decade been the focus of a campaign by the International Association of Athletics Federations (IAAF) that has stigmatized certain women with differences of sexual development (DSDs).

While controversy swirls around issues of sport, sex, gender and fairness, another crucial issue is being overlooked: in my view, such athletes are in effect being asked to act as guinea pigs in medical research, but without the oversight or qualifications that society demands.

Last year, the IAAF introduced limits on blood testosterone levels for women with some types of DSD, in which they have a Y chromosome and are sensitive to testosterone (technically, 46,XY DSD women under the IAAF regulations), in races from 400 metres to 1 mile. These regulations cover all international competitions, including the elite biennial World Championships and the Olympics. On 30 April, the Court of Arbitration for Sport in Lausanne, Switzerland, denied Semenya’s appeal against the IAAF rule (I testified on behalf of Semenya in this process). This week, the South African governing body for athletics has announced it will file another appeal.

International sports organizations such as the IAAF operate in a netherworld of governance — typically incorporated as non-profit organizations, run like businesses, authorized by governments but subject to little oversight or accountability. The IAAF does not consider itself subject to international agreements such as the Universal Declaration of Human Rights, but it has claimed that it adheres to the Helsinki declaration, perhaps the world’s most important benchmark for the ethical principles of medical research with human participants.

As a scholar with expertise in both science policy and international sports governance, I call on the scientific community to hold the IAAF to the research-ethics standards that we expect to apply in every other area of global society.

It has long been understood that, in some cases, sex chromosomes do not match sexual anatomy. As a simple example, some people with vaginas have Y chromosomes, and some people with penises do not. The IAAF estimates that 1 in 20,000 people assigned female at birth have a Y chromosome, resulting in testosterone levels much higher than the typical female range; they must now comply with new IAAF regulations to compete in women’s events. A mandatory medical examination for women suspected of having a condition covered by the regulations includes palpation and measurement of their breasts, vagina, clitoris and rectum. These women must also maintain testosterone levels below 5 nanomoles per litre for at least 6 months. That is well above the 1.7 nanomoles per litre that the IAAF says most women fall under.

However, an expert testifying on behalf of the IAAF has written that women with a Y chromosome who exceed this threshold are much less common than women with two X chromosomes who exceed the limit because they have the medical condition polycystic ovary syndrome (PCOS). Yet women with PCOS are not subject to the regulations.

To reduce their natural testosterone levels, the IAAF states, 46,XY female athletes can take a daily pill, have a monthly injection or have surgery to remove testosterone-producing tissue. But there is no evidence on the efficacy or safety of pills or injections to reduce testosterone and maintain it below an arbitrary level in these otherwise healthy women. The medical treatments are thus what the Helsinki declaration deems “unproven interventions”.

The IAAF explains that the medical treatments are voluntary, and that athletes who choose not to undergo treatment are free to compete in the restricted events as men. The association nevertheless encourages athletes to comply with its requirements, explaining that “the medication helps to change their body to better reflect their chosen gender”.

The Helsinki declaration states that unproven interventions are acceptable only to save life, re-establish health or alleviate suffering. The interventions required by the IAAF fall under none of these categories, and turn otherwise healthy individuals into patients. The World Medical Association, which developed the Helsinki declaration, has advised physicians not to take part in implementing these eligibility requirements, owing to ethical concerns. In a statement this week, it said: “Medical treatment for the sole purpose of altering the performance in sport is not permissible.”

The IAAF argues that its regulations are needed to ensure a level playing field, and that the “female classification” should be “protected”.

I and others have, in peer-reviewed studies, critiqued the integrity of research that the IAAF commissioned to formulate its regulations. But even if we were to accept the association’s assertion that it is necessary to medicalize athletes to ensure fair competitions, the practice would still run afoul of ethical guidelines.

The IAAF acknowledges that implementing its regulations will require “periodic review … to take account of any new evidence and/or relevant scientific or medical developments”. Such review of the consequences of medical treatments constitutes research under bioethical guidelines.

The Helsinki declaration states that unproven interventions must be accompanied by informed consent from the patient, and must be studied to evaluate their safety and efficacy. And medical research involving human participants must be clearly described and justified in a research protocol, which should “include information regarding funding, sponsors, institutional affiliations, potential conflicts of interest, incentives for subjects and information regarding provisions for treating and/or compensating subjects who are harmed as a consequence of participation in the research study”. Such studies must also be approved by an independent research-ethics committee.

The IAAF has followed none of these provisions. International sports organizations have often defied laws and norms, asserting that they are fully autonomous entities. However, the ‘autonomy of sport’ has been challenged following a string of scandals including systemic Russian doping, and corruption in football’s international governing body, FIFA. It should be challenged here, as well.

We cannot ignore how the IAAF is flouting decades of worldwide progress in respecting human rights and dignity. If the association is going to stipulate that athletes with certain DSDs are eligible to compete only if they undergo unproven medical interventions, it should be required to prepare a human-study protocol, secure approval from an independent ethical-review board and have any subsequent research overseen and published. I doubt that any board would countenance such research, but the exercise would make it clear that the IAAF’s new requirements are ethically indefensible.