The International Association of Athletics Federations (IAAF), has set a new rule that will see female runners with naturally high testosterone compete with the men or change events.
The world athletics governing body said athletes who do not want to comply with the rule would have to take medication before the beginning of any IAAF event.
The rules, which start on 1 November 2018, would apply to women who race in track events from 400m up to the mile.
The IAAF believes the new measures will stop women with high testosterone levels gaining a competitive advantage.
Olympic 800m champion Caster Semenya is expected to be among those affected.
The South African runner has previously been asked to undertake gender testing by athletics chiefs but no results have ever officially been made public.
South Africa Athletic Federation said they will support all their athletes who may be affected by this new ruling.
Similar restrictions brought in by athletics’ world governing body, the International Association of Athletics Federations, were suspended following a legal challenge by the Indian sprinter Dutee Chand in 2015.