STATEMENT: Petroleum jelly makes your eyelashes grow. Facts: Coating your lashes with petroleum jelly to promote eyelash growth is a popular statement that has spread like wildfire over the years. Using petroleum jelly (an emollient) on your eyelashes will help condition and moisturize the eyelashes, but will not make them grow. Applying it on your eyelashes keeps them stronger and less prone to falling out. An illusion of thicker eyelashes is caused by petroleum jelly sticking to the lower base of the eyelash root. Want to read more? Subscribe to one of our monthly plans to continue reading this article.