A study in this week’s PLOS Medicine finds that the painkiller diclofenac (a non-steroidal anti-inflammatory drug (NSAID) in the same class as aspirin) is the most commonly used NSAID in the 15 countries studied and is included in the essential medicines lists of 74 low-, middle- and high-income countries, despite its known tendency to cause heart attacks and strokes in vulnerable patients. This risk is almost identical to that of Vioxx (rofecoxib), which was withdrawn from worldwide sales in 2004 because of cardiovascular risk. Researchers writing in this week’s PLOS Medicine call for diclofenac to be removed from national essential medicines lists and to have its global marketing authorisations revoked.