Olestra (Olean)

Procter & Gamble's calorie-free fat substitute was approved by the FDA in 1996 for snack foods like Lay's WOW chips and Pringles Fat Free. The problem: it caused "anal leakage" (the FDA's actual term in required warning labels) and blocked absorption of fat-soluble vitamins. Canada and the EU never approved it. The FDA removed the warning label requirement in 2003, arguing side effects were minimal at normal consumption levels. Sales collapsed anyway — "anal leakage" on a chip bag is not a marketing advantage. WOW chips were renamed and eventually discontinued. Olestra is technically still FDA-approved but effectively dead in the market.