Isolated from the plant Artemisia annua, or sweet wormwood, artemisinin, and its derivatives are powerful medicines known for their ability to swiftly reduce the number of Plasmodium parasites in the blood of patients with malaria. Artemisinin-based combination therapies (ACTs) are recommended by WHO as the first-line treatment for uncomplicated P. falciparum malaria. Expanding access to ACTs in malaria-endemic countries has been integral to the remarkable recent success in reducing the global malaria burden. The number of ACT treatment courses procured from manufacturers increased globally from 187 million in 2010 to 409 million in 2016.

ACTs combine artemisinin derivatives with a partner drug. The role of the artemisinin compound is to reduce the main parasite load during the first 3 days of treatment, while the role of the partner drug is to eliminate the remaining parasites. In patients who are infected with artemisinin-resistant strains of malaria, the artemisinin compound is less effective in clearing all parasites within this 3-day period. However, patients are still cured as part of a longer treatment regimen, provided that they are treated with an ACT containing a partner drug that is effective in that geographical area. WHO currently recommends 5 different ACTs.