Botox is more ubiquitous than yoga pants in Hollywood. But women (and men) in Asia have been taking part in a different injection "trend" for years: saline bagel-shaped injections on one's forehead.

"National Geographic Taboo" chronicles the bizarre beauty treatment in an upcoming episode set in Tokyo, following three people who opt into the temporary forehead injections which have become a keen part of the Japanese "body modification" art scene.