25 years ago, Viagra kickstarted the second sexual revolution and a controversy unlike any drug before it. Following trials in 1992 for a compound believed to alleviate symptoms for angina, Pfizer’s first in-patient trial for the drug, then known as UK92480, begin in Merthyr Tydfil, south Wales. It isn’t long before volunteer patients report having unexpected erections - fast forward ten years and word of the adverse side effect has travelled from Wales to New York resulting in Viagra’s first release in 1998 with orders soon exceeding predictions. What follows is the big story of the little blue pill.