There was still controversy regarding the physiology of acid secretion in 1964 when a team at Smith Kline & French Laboratories in England started a project to prove the existence of more than one receptor for histamine and to find a substance capable of blocking the effects not blocked by the commonly used antihistamines. The team was convinced that histamine was the final mediator of acid secretion. After 8 years, James Black and his coworkers published evidence of the first histamine2-receptor antagonist, burimamide. As this substance was not suitable for oral therapy, the research continued. Metiamide was synthesized with promising clinical effects but questionable safety. The final answer was cimetidine (Tagamet), approved in England in November 1976. Cimetidine was a breakthrough in the treatment of peptic ulcers. In this article I focus on the human factors lying behind many of the decisions made during the years of research. Without personal courage under stressful conditions, the H2-receptor antagonists might never have reached the market.