A housing project in Puerto Rico is where the most extensive human trials for the birth control pill were conducted. The women who participated in the trials––about 1,500 over several years––didn’t know about possible side effects. The doctors––John Rock and Gregory Pincus––didn’t either, since the pill had only briefly been tested on humans, in a failed trial in Boston. Doses of hormones in the pill were much higher than they are today, and though the usual side effects were nausea and dizziness, sometimes blood clots could cause death. The FDA approved the pill in 1960, and added warnings for those with high blood pressure in 1962, but three women had died in the Puerto Rico trials, and no autopsy was conducted.