18 Experiments That Crossed Every Line, Ranked By Cruelty

At Philadelphia’s Holmesburg Prison, dermatologist Albert Kligman conducted experiments on incarcerated men for decades. Prisoners participated in studies testing creams, medications, and chemicals, often motivated by small payments. Many later questioned whether they understood the risks involved. The research involved universities and corporations, making Holmesburg one of America’s most controversial examples of prison-based medical testing.