Get the Popular Science daily newsletter💡 Breakthroughs, discoveries, and DIY tips sent every weekday. The life-threatening (heart disease, leukemia), embarrassing (impotence, flatulence), and annoying (poison ivy, wrinkles) could all be remedied with Radithor’s main ingredient, “internal sunshine”—that is, highly radioactive radium isotopes. It is a phenomenon that, like the radioactive elements of Radithor, remains dangerous today, if not handled with care. Over the course of the next five years, Byers swallowed an estimated 2,800 or more ounces of water laced with two radioactive isotopes: radium 226 and radium 228. Eben Byers hadn’t been fooled into consuming radium; every bottle of Radithor proudly announced itself as “CERTIFIED Radioactive Water.” Instead Byers had been caught in the intersection where fledgling scientific understanding met an untapped commercial market.