What Happens When You Put Castor Oil On Your Eyelashes Every Day?

Vaseline. Growth serum. Castor oil? This vegetable oil, arguably most commonly known as a simple laxative but generally used for many different purposes including treating acne and other skin inflammation as well as wrinkles and age spots, is also supposedly a little-known beauty go-to for growing your eyelashes thicker, fuller, and longer. 

According to Healthline, castor oil is actually a common ingredient in several of our most-used beauty products due to its naturally hydrating properties. Unlike other ingredients, the oil doesn't clog pores or irritate skin either, so when it comes to natural remedies, it's safer than many others. 

There are plenty of common eyelash mistakes, but is not using castor oil one of them?

First and most importantly, if you are considering utilizing castor oil for eyelash growth on a daily basis, make sure that what you buy is pure castor oil. If it's been blended with other ingredients, it could irritate your skin or have zero effect whatsoever, leaving you with greasy eyelashes for no reason. 

Cold-pressed castor oil, which is clear, and Jamaican black castor oil (which is actually brown, rather than black) are the two most commonly used for at-home beauty practices. 

The latter is generally the preferred choice, but both variations contain the same basic properties. You'll need to do a swatch the day before on your arm to check for any irritation before applying to your eyelashes. 

The best time to use castor oil on eyelashes is before bed, when your eyes are clean and completely free of makeup. Apply a small amount using a cotton swab along the top of your lash line, ensuring none gets in your eyes (if any does, wash thoroughly). Wash it off in the morning.

Although no scientific studies have been conducted yet in relation to castor oil and eyelash growth, evidence suggests ricinoleic acid, which makes up nearly 90 percent of it, may help to reduce or even reverse hair loss. 

Dominic Burg, Ph.D., hair biologist and chief scientist for Évolis Professional, told Byrdie, "Castor oil contains ricinoleic acid as its main component, which is thought to work through stimulating the receptor of a special molecule called prostaglandin E2 (PGE2), which has diverse effects on the body including dilation of the blood vessels, uterine contractions, and bowel activity. The theory is that PGE2 also has a role in hair growth by stimulating hair follicles to enter the growth phase."

However, it's worth noting cosmetic chemist and author Perry Romanowski emphatically told Allure, "Castor oil will not grow hair. There is no evidence for it and no scientific theory supporting that it would work, so yes, it's a total myth." 

So, there's good reason to believe slathering it on your eyelashes every day will do absolutely nothing. If you're still curious, castor oil is cheap, easy to use, and generally safe as long as you take pains to avoid getting it into your eye. It could be worth a try provided a swatch doesn't show any obvious irritation from it.

Although the science on whether castor oil has a significant impact on eyelash growth is still debatable, there's reason to believe that applying it could help hydrate your lashes regardless. 

As board-certified ophthalmologist Ilyse Haberman explained to Cosmopolitan: "Castor oil moisturizes your eyelashes and can make them appear thicker and look like they have more luster." She continued: "It's also possible that it can help prevent lash breakage which, in turn, can lead to healthier growth." 

However, castor oil won't necessarily lengthen your lashes. As dermatologist Mona Gohara clarified: "Castor oil may help your lashes look thicker, denser, or fuller, but it won't help them grow." 

Using it may prevent lashes from shedding, though. And, as Insider points out, this could result in thicker lashes in the long run, which is the main goal overall. Dr. Joshua Zeichner, the director of cosmetic and clinical research at Mount Sinai Hospital, also confirmed that castor oil could have "moisturizing benefits," which "help condition and thicken the hairs themselves." 

Since castor oil wasn't created solely to improve your eyelashes, you might be considering reaching for a specialized serum instead. But it really depends on what kind of outcome you're looking for.

Cosmopolitan advises that, if you want to grow your lashes above all else, a product like Latisse is the safest bet. It's "the only FDA-approved, prescription-strength eyelash serum that actually slows down the 'growth phase' of the hair cycle," giving your lashes more opportunity to grow before they fall out.

Elle further notes that many lash-conditioning products actually contain castor oil as an active ingredient, but the main thing to keep in mind is that consistency in application with whatever product you choose is key to long-lasting results. 

Still, board-certified dermatologist Dr. Karan Lal shared: "For patients who want a natural, less risky eyelash serum, I do recommend castor oil." If your lashes are in need of some TLC, it may still be your best bet. But, if you want to grow your lashes, a serum created for exactly that reason is the smartest option.