6 Eyebrow Mistakes Makeup Pros Warn to Avoid at All Costs

"I like to rub castor oil on my eyebrows and eyelashes every night," explained one makeup artist backstage at Alexander Wang. "It helps to grow the hairs in thicker and stronger, plus it only takes a few months or so to work."

Rather than investing in a pricey eyebrow growth serum, try castor oil to help regrow sparse brows. As a natural oil that easily penetrates the skin to facilitate hair growth, this hack is definitely a worth a try.