#aftermidnight Pepto Bismol, that faintly bubblegum-flavored sludge from your medicine cabinet, was actually once considered something of a wonder drug. Bismuth subsalicylate (BSS), the active ingredient in Pepto, is derived from Bismuth salts. Even as a salt, people have used bismuth since the 18th century for its anti-inflammatory, bactericidal, and antacid properties.