Cape Town - South Africa's Caster Semenya could still be a medal contender at this year's IAAF World Championships in Doha in September, just not over her preferred 800m distance.

READ: The full CSA verdict

On Wednesday, Semenya lost her appeal against the IAAF at the Court of Arbitration for Sport (CSA) against rules designed to decrease naturally high testosterone levels in some female runners.

Semenya, a two-time Olympic champion in the 800m, will now be forced to medicate to suppress her testosterone levels if she wants to defend her world title in September in Doha, Qatar.

It's widely deemed to be fact that Semenya's 800m time would slow by as much as seven seconds through medication, ruling her out of any chance of a medal at any championship or Olympic Games.

However, while the IAAF believes female runners with high testosterone levels have an unfair advantage in events from 400m to the mile (1 600m), CSA's judges want the IAAF to apply the rules only up to the 800m as they believe the evidence is not clear that women with hyperandrogenism - or those with "differences of sexual development" (DSD) - have a competitive advantage in the 1 500m.

"The CAS Panel suggested that the IAAF consider deferring the application of the DSD Regulations to these events (1 500m and the mile) until more evidence is available," the court said.

Assuming the IAAF abide by that ruling - which it did not make reference to in a statement published on its website - it could give Semenya a route to compete at the Doha world championships, starting on September 28, without taking medication.

READ: Caster tweets after losing testosterone ruling

Semenya was the bronze medal winner in the 1 500m at the last IAAF World Championships in 2017 in London in a race that was won by Kenya's Faith Kipyegon in 4:02:59. American Jennifer Simpson was second (4:02:76) while Semenya took third in 4:02:90 - a mere 0.31 behind the winner.

Ethiopia's Genzebe Dibaba holds the current 1 500m women's world record at 3:50:07.

Last week at the ASA Senior Championship in Germiston, Semenya won the SA title in the 1 500m in 4:13.59.

Semenya also took the 5 000m title at the same meeting in a time of 16:05.97 giving her potentially a second shot at a medal for South Africa.