Roxadustat is an anti-anaemia drug which stimulates the production of red blood cells in the body.
Halep has always maintained her innocence and said the accusations were “scandalous”.
While her case was partially upheld, Cas ruled Halep “on the balance of probabilities” had not taken roxadustat intentionally.
With the French Open running between 26 May and 9 June, Halep is looking to build up time on the court.
Halep won the French Open in 2018 and lifted the Wimbledon title in 2019.