So, how does this explain the multitude of posts from people who have seen accelerated hair growth? "Castor oil contains a high percentage of ricinoleic acid, which is an omega-9 essential fatty acid. This can help as an anti-inflammatory and improve circulation, which may help with hair growth," says Dr. Day. But while that is one theory, the risk that castor oil will cause irritation is high. Not to mention the fact that putting it around your eyes can result in the oil coating your corneas (not good). If noticeable lash and brow growth is your goal, there are other, legit alternatives. "If people are interested in longer eyelashes, Latisse is really the only proven, effective treatment." says cosmetic chemist Perry Romanowski