CINCINNATI—Procter & Gamble Co., which has suffered through a decade of market-share losses and stagnating profits, hopes its redemption lies in a koala-shaped maxi pad.

Called the “Koala HuHu,” the extra-long overnight pad launched this spring in China. Part of P&G’s Whisper brand—which is called Always in the U.S. and elsewhere—it targets teenage girls with cartoon marsupials snoozing on the box, and is beating rivals despite commanding higher prices. To develop the product, the consumer-products giant abandoned...