It's a fact that as you age, the hair on your head, eyebrows, and especially your eyelashes start to thin. Because most of us want long, thick, full eyelashes, we are willing to invest in eyelash extensions, falsies, volumizing mascaras, and even lash-boosting supplements to get a mile-long fringe. One of the most underrated ways to get better-looking lashes is with castor oil. It's long been used for its lash-boosting abilities, making castor oil for eyelash growth a go-to treatment. But using it on the eyelashes works differently than eyelash serums, so there's plenty to unpack if you want to give it a shot. We tapped two dermatologists and a trichologist for their expert insight and the truth about using castor oil for eyelash growth. Meet the expertMarisa Garshick, MD, is a board-certified dermatologist in New York City and New Jersey.Aleksandra Brown, DO, is a board-certified dermatologist in Virginia.Gretchen Oligee is a trichologist (AKA scalp expert) for BosleyMD. What Is Casto...