Caster Semenya has filed an appeal to the Federal Supreme Court of Switzerland challenging the recent ruling against her by the Court of Arbitration for Sport, the double Olympic champion has announced.
Semenya's appeal against the introduction of a testosterone limit for women with naturally-occurring high levels of the hormone by athletics' world governing body the IAAF was rejected by CAS on 1 May.
The ruling means she and other athletes with similar genetic conditions will have to take hormone suppressants to bring their testosterone down to a level closer to the typical female range.
On the filing of her new appeal on Wednesday, Semenya said: "I am a woman and I am a world-class athlete. The IAAF will not drug me or stop me from being who I am."
Semenya intends to ask the Swiss Federal Supreme Court to set aside the decision of CAS in its entirety, according to a statement issued on her behalf.
However, it is understood that her best chance of success is if the initial ruling is deemed to be incompatible with public policy.
Dr Dorothee Schramm of Sidley Austin LLP in Geneva is leading Semenya's appeal and said: "The IAAF regulations violate the most fundamental principles of Swiss public policy. In the race for justice, human rights must win over sporting interests."
Semenya's South African lawyer Gregory Nott added: "It is gravely concerning that the IAAF has called on doctors to 'clarify' the gender identities of female athletes and justified medical interventions on female athletes as 'gender-affirming'.
"Such views are based not in modern science or medicine. Instead, they reflect an outdated and deeply flawed socio-cultural stereotype of what it means to be a woman."
One of the three CAS judges agreed with Semenya and the IAAF was told there were significant caveats to the court's approval of its 'eligibility regulations for female classification (athletes with differences of sex development)'.
Semenya was asking sport's highest court to declare the rules as "invalid and void with immediate effect" because they were "discriminatory, unnecessary, unreliable and disproportionate".
But, in a statement to announce its decision, the Lausanne-based court said: "By majority, the panel has dismissed the requests for arbitration considering that the claimants were unable to establish that the DSD regulations were 'invalid'.
"The panel found that the DSD regulations are discriminatory but the majority of the panel found that, on the basis of the evidence submitted by the parties, such discrimination is a necessary, reasonable and proportionate means of achieving the IAAF's aim of preserving the integrity of female athletics in the restricted events."
Those events are every race between 400 metres and a mile, including relays, as those are the only events the IAAF has so far been able to statistically demonstrate that high testosterone gives DSD, or intersex, athletes a significant advantage.
Semenya is set to race over 3,000m at the Diamond League Prefontaine Classic on June 30, her first race since the DSD ruled came into effect on 8 May.