Lip plumpers are the JT LeRoy of the cosmetics world: the hottest novelty in years, but are they for real? Believe it or not, yes. The indie cosmetics company DuWop started the trend five years ago with Lip Venom, a peppery gloss that irritates the lips into plumping ever so slightly. Several other companies have gotten into the game, mouthing off that their topical treatments are better than collagen injections. But customers of these gooey glosses don’t escape pain: The best plumper, Too Faced’s Lip Injection, bites and stings and leaves lips numb. You better believe they swell—for up to four hours. Available at Sephora, Nordstrom, and toofaced.com.