Filler in a bottle. Those four words continue to pop up in beauty-focused social feeds everywhere, on posts enthusiastically touting the skin-plumping abilities of Volufiline. Which, if you are to believe the acolytes of your algorithm, can camouflage smile lines, revive deflating cheeks and pouts, and restore under-eye hollows. On TikTok, devoted users are MacGyvering their bottles of The Ordinary’s Volufiline with rollerball tops to make application easier; they’re sharing before-and-afters of newly volumized features; and they’re trying to prove the plumping powers of Medicube’s new Pink Collagen Volume Multi Balm Stick (which features Volufiline) by testing it on their, wait for it… fingertips. Reddit threads are also awash with curious shoppers seeking the truth about the latest skincare craze. But what exactly is Volufiline, and can the niche ingredient live up to the online hype?