Castor Oil Is the Secret to Healthy Hair, Trichologists Say—Here's What It Can Do

When it comes to multipurpose oils and serums, castor oil is at the top of the list. It can be used as an antibacterial agent, moisturizer, pain-relieving lubricant, and so much more. But its particularly beneficial for one of the most sensitive parts of our body: our scalp. Whether you struggle with an itchy scalp, dry ends, or hair loss, treating the scalp with castor oil could be the solution to long and luscious hair.

The history of castor oil dates all the way back to 4,000 B.C., when ancient Egyptian ruler Cleopatra used the ripe seeds of the castor oil plant to brighten the whites of her eyes. To add to its versatile history, the oil has most recently been used to address hair and scalp damage, according to trichologist Jay Small. “The original purpose of castor oil was not as an ingredient in beauty products,” he explains, noting that overtime, however, "people started to experiment with oral and topical uses, finding that it has many benefits.” 

Where Does Castor Oil Come From?

Castor oil is sourced from the seeds of the Ricinus communis plant, more commonly referred to as the castor bean or castor oil plant. The seeds go through a heating process to remove the toxic enzyme ricin, which prepares them to be used safely by consumers.

Why Is Castor Oil So Popular?

Castor oil is popular for a multitude of reasons, but the most important one is due to its chemical makeup. “Castor oil contains ricinoleic acid, a type of fatty acid, which may boost circulation in the scalp and subsequently promote healthier and stronger hair,” Small explains. “Its unique chemical structure gives it the ability to act as both a non-drying oil and a humectant, making it capable of drawing moisture to the hair and locking it in.” Few hair oils can achieve the same effect.

In addition to its strong chemical makeup, castor oil is also virtually harmless in small doses. “There are few things that have so many benefits with few negative side effects,” Small says. Whether you suffer from dry skin, damaged hair, or additional irregularities, castor oil might just be able to help.

The Benefits of Castor Oil

It Can Create and Retain Moisture in the Hair

Castor oil is an excellent moisturizing agent to help draw out and retain moisture in our hair, explains hairstylist Tiffany Rose Dean. “Castor oil is rich in vitamin E and fatty acids, which makes it a natural hair moisturizer; it easily seeps into your hair, resulting in a smoother and softer feel.” Once the castor oil seeps into the hair, it locks in moisture by sealing the hair follicles with its protective compounds. 

It Soothes an Irritated Scalp

If you suffer from an itchy scalp, castor oil is just what you need. “This oil has anti-inflammatory and antimicrobial properties, making it excellent for managing irritated and dry scalp,” says Dean. Scalp inflammation typically presents as itchy, red, and scaly patches on the scalp, so if you identify the onset of symptoms, you can reach for that bottle of castor oil.

It Provides Elasticity to the Hair

Many of us dream of hair that doesn’t break easily, and applying castor oil to the hair can get you one step closer to achieving that dream. Hair is especially susceptible to breakage while styling—an onslaught of brushing, pulling, and scrunching can cause delicate hair follicles to snap off. By routinely massaging the hair and scalp with castor oil, you’ll notice less breakage over time.

It Actively Promotes Hair Growth

Have you been trying to grow your hair out with little to no success? Try castor oil. Small and Dean both agree that topically applying castor oil to the hair can encourage growth in thinning areas. “While it can’t do it on its own, it will leave your scalp moisturized, making it a great environment to encourage hair growth,” Dean explains. Although hair growth requires a holistic approach–including dietary changes, exercise, and other factors that play a role in hair growth–using castor oil can boost its ability to do so. 

It Adds a Natural Shine to Hair

Who doesn’t want shiny, luscious, gorgeous hair? Nobody. Castor oil contains humectants—or active ingredients that help retain moisture—which leave behind a natural shine. “Castor oil adds a glossy shine to your hair, especially when applied to your mid-lengths and ends,” Dean says. During the hair oiling process, don't forget to coat the bottom half of your hair for extra shine.