In 1967, during the Cultural Revolution, Tu Youyou was assigned to lead a research group within Project 523, a top-secret military project initiated by Chairman Mao Zedong to find a new treatment for malaria, which was affecting soldiers in Vietnam.

Tu Youyou and her team began systematically reviewing ancient Chinese medical texts and traditional remedies in search of potential treatments for malaria. They screened thousands of compounds derived from various plants and herbs.

After numerous unsuccessful attempts, the team focused on Artemisia annua, commonly known as sweet wormwood. They extracted a substance that showed promising anti-malarial activity in mice, but the results were inconsistent.

After analyzing the historical texts more closely, Tu Youyou realized that high temperatures used in the original extraction process were damaging the active ingredient. She experimented with lower-temperature extraction using ether, which yielded a much more potent and stable compound.

To ensure the safety of the extract, Tu Youyou and other members of her research team volunteered to be the first human subjects to test the artemisinin extract. This demonstrated her dedication and commitment to the project.

Tu Youyou and her team successfully isolated artemisinin, the active anti-malarial compound from Artemisia annua. This marked a major breakthrough in the search for a new malaria treatment.

The research findings on artemisinin were published in Chinese journals, initially receiving limited international attention due to the political climate and the language barrier.