By Erin Lukas
Oct 17, 2018 @ 12:30 pm
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There's no shortage of eyelash serums on the market. But as a beauty editor, the number one question I get asked by friends is whether castor oil makes eyelashes grow longer. 

Googling "castor oil as a lash treatment" makes it even more confusing to figure out if the vegetable oil is worth slathering on your lashes. Instead of a definitive answer, you pull up dozens of mixed results in Reddit threads and posts by beauty bloggers. That's why I turned to two experts to find out if castor oil is better than Meghan Markle's beloved Revitalash.  

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The hard answer is no. Dermatologists Dr. Mona Gohara and Dr. Joshua Zeichner both tell me that there's no scientific evidence that proves that castor oil helps eyelashes grow longer. "It's unclear whether castor oil truly promotes hair growth or simply conditions and plumps the hair shaft itself," says Dr. Zeichner. 

So, what about all of those people on Reddit who claim that their lashes are longer because they coated their lashes with castor oil for weeks? It's most likely just an optical illusion. "It works like a hair conditioner to coat and protect the hair shaft itself so it looks thicker and can grow longer," explains Dr. Zeichner. 

VIDEO: 5 Ways to Enhance Your Eyelashes 

If you're still set on trying castor oil because buying a bottle of it is a whole lot cheaper than any of the lash serums you've had your eye on, proceed with caution. Dr. Gohara says that using oils can block the eye glands, which can cause styes and cysts. If you have eczema, sensitive skin, or allergies, Dr. Zeichner recommends not using castor oil on your lashes. 

The good news is that any irritation you might experience when using castor oil on your lashes will go away in a few days when you stop using it. Applying over-the-counter hydrocortisone cream can help, too. 

Considering the low stakes of this beauty DIY, chances are the worst thing that will happen is that you waste $5 on a bottle of castor oil.