Can you actually use castor oil as a lash serum? Here's what derms say (2024)

Between the dexterity needed to apply false eyelashes and the cost of lash extensions, it’s easy to understand the appeal of using castor oil for eyelash growth. The common lash serum alternative costs roughly £10 for a hefty bottle and is as easy to apply as mascara.

The idea that castor oil can improve your natural eyelashes may seem like wishful thinking, particularly if you’ve had mixed results with DIY beauty tips in the past. At the same time, the popularity of castor oil among beauty enthusiasts is hard to overlook.

If you’re curious whether using castor oil for eyelash growth is worthwhile, here’s what you should know.

Meet the experts: Hadley King, MD, is an NYC-based board-certified dermatologist specializing in medical and cosmetic dermatology. Cameron Rokhsar, MD, is a double board-certified dermatologist and founder and medical director of New York Cosmetic, Skin & Laser Surgery Center. Michele Farber, MD, is a board-certified dermatologist at Schweiger Dermatology Group in Philadelphia. Ava Shamban, MD, is a Beverly Hills-based dermatologist and founder of AVA MD Dermatology.

Does castor oil grow eyelashes?

If you’re unfamiliar, castor oil is a vegetable oil that’s extracted from the seeds of the castor bean plant, a type of shrub found in Africa, South America, and India. It's been a major part of common hair oiling practices in India since long before it started popping up on social media, thanks to its potential to nourish the hair and scalp.

A component of castor oil, ricinoleic acid, is responsible for both its laxative effects and potential eyelash growth benefits. The theory is that the ricinoleic acid in castor oil may activate a receptor which could boost the natural production of a type of prostaglandin, explains New York City-based dermatologist, Hadley King, MD.

That’s noteworthy, since certain substances that activate a prostaglandin receptor (aka prostaglandin analogs) are known to boost hair growth, says Dr. King. For example, bimatoprost, the hair growth-enhancing ingredient in the FDA-approved prescription eyelash serum Latisse, does just that.

Still, the notion that castor oil encourages eyelash growth may be a reach. 'There is no scientific evidence showing that castor oil stimulates hair growth,' says Dr. King. 'Castor oil has been shown in a study to increase hair luster, but there are no studies that show that castor oil directly causes hair growth. There are plenty of anecdotal stories, but there is no scientific evidence.'

So, if your hope is to choose the most research-backed option above all else, you’re better off looking elsewhere.

'Clinical trials of prescription products like Latisse have demonstrated significant improvements in lash length, thickness, and darkness when applied consistently over several weeks,' says Cameron Rokhsar, MD, founder and medical director of New York Cosmetic, Skin & Laser Surgery Center. 'Castor oil lacks this type of scientific scrutiny and the evidence is only anecdotal.'

Side effects of using castor oil on eyelashes

Castor oil isn’t for everyone. 'There’s a risk of irritation or allergic reaction,' says Michele Farber, MD, board-certified dermatologist at Schweiger Dermatology Group in Philadelphia. 'If you choose to use castor oil around the eye, be very careful to only apply it to the eyelashes and avoid getting in the eye.' If it ends up in your eye, it can temporarily blur your vision.

If you’re pregnant or breastfeeding, it’s best to avoid using castor oil for eyelash growth altogether, says Ava Shamban, MD, Beverly Hills-based dermatologist and founder of AVA MD Dermatology. There’s a lack of data around the safety of using castor oil around the eyes in these groups.

How to use castor oil for eyelashes

With the above caveats in mind, it’s generally safe to use castor oil for eyelash growth, according to Dr. King. If you’d like to try it out, she suggests applying it once or twice per day. You want to apply the oil to the base of your eyelashes as well as the hairs themselves, says Dr. Rokhsar.

A lot of people opt for pure castor oil in hopes of improving their eyelashes. Naturally, plenty of brands have caught onto the popularity of castor oil as an eyelash treatment, and include a mascara wand with bottles of castor oil that you can use for application.

However, choosing a lash serum that contains castor oil, rather than straight castor oil, is your best bet, in Dr. Shamban’s eyes. In addition to the aforementioned side effects, 'castor oil is very thick and can be occlusive,' says Dr. Shamban. That means it could end up clogging your pores or irritating your skin. You’ll be less likely to experience negative effects from a product containing castor oil compared to pure castor oil, says Dr. Shamban.

All things considered, there’s little risk in trying castor oil if you’re wondering what all the hype is about. Research on its effects is lacking, but there’s something to be said for its word-of-mouth credibility.

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