Would it be ethical or legal for doctors in South Africa to administer testosterone-reducing drugs to Caster Semenya?

The Court of Arbitration for Sport recently confirmed that the decision by the International Association of Athletics Federations to require hyperandrogenic female athletes such as Caster Semenya to reduce their testosterone levels to compete in certain races has been widely condemned. The World Medical Association has warned doctors not to assist in implementing the decision, as it would be unethical. The same would apply in terms of the Health Professions Council of South Africa's rules of professional conduct. Such treatment is 'futile' in medical terms, and does not serve the purpose of providing healthcare. Therefore, doctors may lawfully refuse to prescribe it. The decision is a violation of Semenya's constitutional rights and would be regarded as unethical should doctors comply with it. However, the prescription of such drugs would not be unlawful if Semenya gave informed consent to taking them. Such consent would not be a defence to a disciplinary hearing on unprofessional conduct, but would be a good defence to any legal action arising from unpleasant side-effects - provided they were explained to her.