Caster Semenya faces new classification after IAAF ruling

South African will need to artificially reduce testosterone levels in order to compete

South Africa’s Caster Semenya celebrates with her national flag after winning the athletics women’s 800m final during the 2018 Gold Coast Commonwealth Games. Photo: Saeed Khan/Getty Images

Caster Semenya will need to reduce her natural testosterone levels with immediate effect, by use of daily hormonal contraceptives, if her future times on the track are to be valid for record purposes – or if she intends on defending her Olympic and World titles over 800m.

The IAAF, the governing body of world athletics, have approved new eligibility regulations for a separate female classification to be known as an Athlete with Differences of Sexual Development (or DSDs), which will directly impact on Semenya and likely bring an end to the South African woman’s dominance over the shorter middle distance events in recent years.

For now, the new regulations will only apply to women’s international track events from 400m to the mile, and doesn’t necessarily ban women with DSDs from competing: they will still be free to race in national competitions, in events other than 400m to the mile, and in male or ‘intersex’ classified races. For all global times and record purposes however the new regulations will apply.

These new regulations will also prove controversial – and may end up in the Court of Arbitration for Sport (CAS), should a female athlete such as Semenya take a legal case against the IAAF.


In detailing the new eligibility regulations, the IAAF have outlined both their need and also their purpose, and which under Competition Rule 141, will come into effect on November 1st of this year. This is to allow female athletes with DSD’s a six-month “compliance” period, whereby they must undergo the testosterone reduction should they wish to avoid having to stand down from competition once the regulations come into effect.

The new DSDs rule also replaces the IAAF’s previous regulations governing eligibility of females with hyperandrogenism, which was successfully appealed to CAS, and has been suspended since 2015: according to the IAAF, “the previous hyperandrogenism regulations needed to be rewritten, to narrow their scope to certain track events, and to strengthen the restrictions applicable to athletes with DSDs participating in those events.

“The result is these new regulations, which seek to facilitate the participation in the sport of athletes with DSDs on terms that preserve fair and meaningful competition in the female classification.”

Semenya, 27, is the double Olympic champion and reigning World champion over 800m, and again underlined her superiority at the Commonwealth Games earlier this month when winning 800m-1,500m gold, the latter in a new South African record of 4:00.71. The only women who have consistently got close to Semenya over 800m are Francine Niyonsaba from Burundi, who finished second in Rio, and Kenyan Margaret Wambui, who finished third, both also understood to benefitting from the effects of hyperandrogenism.

While not naming any individual, these are among the athletes to be directly impacted by the new IAAF regulations. In explaining the new rule, the IAAF have also outlined how it will be enforced, and the evidence on which they have based their new limits of testosterone on female athletes (5 nmol/L in blood).

“Most females have low levels of testosterone circulating naturally in their bodies (0.12 to 1.79 nmol/L in blood); while after puberty the normal male range is much higher (7.7 - 29.4 nmol/L). Absent a DSD or a tumour, no female would have serum levels of testosterone approaching 5 nmol/L, but individuals with DSDs can have very high levels of natural testosterone, extending into and even beyond the normal male range.

“There is a broad medical and scientific consensus that if these individuals are sensitive to androgens (i.e., they have properly-functioning androgen receptors), such very high levels of natural testosterone can increase their muscle mass and strength, as well as their levels of circulating haemoglobin, and so significantly enhance their sporting potential.

“Experts consulted by the IAAF have gathered and reviewed all of the published evidence and data, which indicates that increasing the level of circulating testosterone from the normal female range to the normal male range leads to increased muscle mass and strength and higher haemoglobin levels.

“In particular, increasing testosterone levels in women from 0.9 nmol/L to just 7.3 nmol/L increases muscle mass by 4% and muscle strength by 12-26%; while increasing it to 5, 7, 10 and 19 nmol/L respectively increases circulating haemoglobin by 6.5%, 7.8%, 8.9% and 11% respectively. Taking all available knowledge and data into account, the experts estimate that the ergogenic advantage in having circulating testosterone levels in the normal male range rather than in the normal female range is greater than 9%.

“The significant over-representation of DSD athletes in certain events, and their success in those events, provides further indirect but strong corroboration of the above. In addition, the IAAF has gathered observational data about the difference in performance levels of DSD athletes depending on whether or not their testosterone levels are suppressed, including data showing that suppression of the levels of circulating testosterone of three DSD athletes from 21-25 nmol/L to below 2 nmol/L coincided with their performances decreasing by an average of 5.7%.

“This evidence shows clearly that (at least in certain events) DSD athletes with levels of circulating testosterone in the normal male range have a very significant competitive advantage over female athletes with testosterone levels in the normal female range, which justifies requiring DSD athletes to reduce their testosterone levels down to the normal female range in order to compete in the female classification in such events.”

Only the IAAF medical manager can initiate an investigation in relation to any female athlete considered to be competing with DSDs, and therefore required to use hormonal contraceptives to bring her testosterone below 5 nmol/L, in order to compete in the new ‘restricted events’: “no other measures are required. In particular, surgical anatomical changes are not required in any circumstances.”

The IAAF insist this is in the interest of fairness: “These regulations exist solely to ensure fair and meaningful competition within the female classification, for the benefit of the broad class of female athletes. In no way are they intended as any kind of judgement on or questioning of the sex or the gender identity of any athlete. To the contrary, the IAAF regards it as essential to respect and preserve the dignity and privacy of athletes with DSDs, and therefore it will continue to handle all cases arising under these regulations in strict confidence.”

They’ve also outlined why DSD’s are being separated from other perceived athletic advantages, including height or weight: “Where a female athlete has a DSD that gives her levels of circulating testosterone in the male range, and she is sufficiently androgen-sensitive for those levels to have a material androgenising effect, e.g., increasing her lean body mass and/or her levels of serum haemoglobin, then treating like cases alike means requiring her to reduce her testosterone levels to below 5 nmol/L in order to compete in the female classification in the most obviously affected events.

“To the best of our knowledge, there is no other genetic or biological trait encountered in female athletics that confers such a huge performance advantage.”