The 20 th Essential Medicines List, published on 6 June 2017, marks the 40th anniversary of this flagship WHO tool to expand access to medicines. The updated list adds 30 medicines for adults and 25 for children, and specifies new uses for 9 already-listed products, bringing the total to 433 drugs deemed essential for addressing the most important public health needs globally. The 20 th List also provides new advice on which antibiotics to use for common infections and which to preserve for the most serious syndromes, based on a thorough review of all essential antibiotics. The aim is to optimise antibiotic use and reduce antibiotic resistance without restricting access. Other important additions include medicines for HIV, hepatitis C, tuberculosis and cancer.