Using Castor Oil for Hair Can Help Improve Scalp Health, Hydration, and Even Boost Growth

In a day and age when hair care products seem to multiply every day, each promising rapid results—whether it’s faster hair growth, shinier strands, or a healthier scalp—it’s easy to overlook the tried-and-true classics. With its long history and proven benefits, castor oil for hair is one of them. The simple yet effective ingredient boasts a centuries-long history, dating all the way back to ancient Egypt. Today, the oil remains a staple in the beauty world, not just for its deep historical roots (pun intended) but for its scientifically-backed benefits, too.

Hair experts and dermatologists alike vouch for castor oil’s ability to quench dry hair, promote healthy growth, and even thicken fragile strands. In fact, it’s found in everything from shampoos and conditioners to hair masks and leave-in treatments, thanks to its unique blend of essential fatty acids, antioxidants, and vitamins.

If you’re curious about how this ancient elixir can transform your hair routine, you’re not alone. Ahead, we consulted a few experts to get more intel on using castor oil in your hair. Keep reading for the benefits of using castor oil, how to incorporate it into your hair routine, expert tips for achieving the best results, and more.

What Is Castor Oil?

Castor oil, also known as Ricinus communis, is a nutrient-dense vegetable oil derived from castor beans. The oil is typically colorless, but depending on how it’s made, it can also be yellow or deep brown. It’s anti-inflammatory, filled with antioxidants, and has antibacterial properties, which is why the ingredient is commonly found in hair care products.

The Benefits of Castor Oil on Your Hair

• Nourishing and strengthening: If you look at castor oil’s molecular structure, explains Atlanta-based dermatologist Tiffany L. Clay, M.D., you’d see that it’s a glycerol with a long-chain fatty acid. So what does this mean? Simply put, fatty acids are excellent at nourishing hair follicles. The outer layer of the hair shaft is covered in tessellating, scale-like structures called cuticles, and when the hair is damaged, those become flayed and flared, resulting in frizz and dullness. Castor oil, however, "can seal and allow the cuticle to lie flatter," according to Clay, resulting in better shine and decreased frizz. Castor oil is also rich in “ricinoleic acid, vitamin E, and omega-6 fatty acid, making it beneficial for moisturizing and strengthening,” adds celebrity hair stylist Jennifer Thomas.

• Could help with hair loss: "While there are currently no conclusive clinical studies proving that [castor oil] causes hair to grow faster,” says Dr. Rebecca Marcus, a board-certified dermatologist and founder of MaeiMD, “we do know that castor oil stimulates prostaglandin E2, which causes vascular dilation and increased circulation, which could help to stimulate follicles.” That could mean improved hair growth for you. NYC-based dermatologist and hair loss specialist Dhaval G. Bhanusali, M.D. agrees. "There is some proposed benefit of castor oil with improving penetration of topicals and even hair growth," he says. "That being said, I don't think the scientific evidence is there to make any sizable claims, particularly for stimulating new hairs."
• If you're suffering from hair thinning or hair loss, Dr. Bhanusali says, "I can't stress enough how important it is to go see a board-certified dermatologist. We now have so many new options and it's much easier to create a comprehensive plan for early hair loss than later in the game." Thomas also agrees that scientific evidence is limited when it comes to clinically proving that castor oil promotes hair growth. “However,” she says, “when used on the scalp along with massaging, it can improve scalp circulation and indirectly support healthy hair growth.” Plus, she adds, “castor oil reduces inflammation of the scalp and may help mitigate some causes of hair shedding.” In short, much like a hair growth shampoo, while castor oil alone won't cure hair loss or thinning, it can support hair health, plus make your scalp a better environment for hair growth and retention in the long-term.

• Helps with scalp health: When it comes to scalp care, Thomas agrees that castor oil may help alleviate scalp irritation and inflammation, thanks to its antifungal and antibacterial properties. However, she notes that results can vary from person to person. Also, due to its cleansing properties, castor oil can help eliminate flakes caused by a dry scalp.

Who Should Use Castor Oil For Hair?

If you have a dry or flaky scalp or dry, brittle hair, castor oil is definitely an ingredient to consider adding to your hair care routine. Still, you should take hair type into consideration. "Castor oil tends to weigh hair down and can be difficult to wash out," explains Thomas. "While thicker hair may tolerate oil better, fine hair is more easily weighed down.

How to Use Castor Oil for Hair

If you're using castor oil as a leave-in treatment, Dr. Clay recommends warming a small amount of the oil between your palms and smoothing it along the ends of your hair on a weekly basis. Meanwhile, for use as a deep conditioner, Dr. Marcus says, "Before washing your hair, I recommend applying it to dry scalp and hair, covering with a shower cap, leaving in for 20 minutes, and then shampooing and conditioning as normal."

However, as with any hair oil, it's important to start small and be aware of how your hair type responds to oil products. "For those with coarse, curly or dry hair, they may wish to apply castor oil to the ends of hair and leave in, as it’s a fairly light oil," says Dr. Marcus. "For those with fine or thin hair, though, they’ll probably prefer to use it as a pre-wash treatment as above, washing out so as to avoid weighing hair down and a greasy appearance."

Before going all in on castor oil, Thomas recommends spot-treating specific areas on your scalp to test your reaction and results first. And if you're not comfortable using pure castor oil for fear of overdoing it, there are a number of less intense options, including shampoos, conditioners, hair masks, and serums.

Best Castor Oil Hair Products

• Best Castor Oil Overall: Heritage Store Organic Lavender Castor Oil
• Best Castor Oil Treatment for Dry or Damaged Hair: SheaMoisture Jamaican Black Castor Oil Strengthen & Restore Hair Mask
• Best Castor Oil Shampoo: Okay Black Jamaican Castor Oil Shampoo
• Best Castor Oil Conditioner: As I Am Jamaican Black Castor Oil Conditioner

Other Castor Oil Hair Products We Love

Meet the Experts

Dr. Rebecca Marcus

Dr. Rebecca Marcus is a board-certified dermatologist who specializes in medical, surgical, and cosmetic dermatology. She has nearly two decades of experience and completed her residency along with a clinical research fellowship at Columbia University. Since then, in addition to practicing dermatology, she has founded her own skincare line, Maei MD.

Dr. Dhaval Bhanusali

Dr. Bhanusali is an NYC-based, board-certified dermatologist based in NYC. After completing his studies at Michigan State University's medical scholars program, he launched the digital healthcare companies Health Digital, HairStim Labs, and Skin Medicinals. He has since consulted for P&G, Neutrogena, Skin Ceuticals, Cerave, EltaMD, Skin Medica, Fast Beauty Co., and 86 Elm.

Dr. Tiffany Clay

Dr. Clay is a board certified dermatologist who studied at Dillard University. She is a member of the American Academy of Dermatology, American Society for Dermatologic Surgery, Women’s Dermatologic Society, Georgia Society of Dermatology and Dermatologic Surgery, Atlanta Association for Dermatology, and Dermatologic Surgery and the National Medical Society. Dr. Clay is passionate about preventing skin cancer and providing high-quality care to oft-overlooked patients of color, and is currently based in Atlanta.

Jennifer Thomas

Jennifer Thomas discovered her passion for hair at just 10 years old. Now, at 55, she has turned that passion into a lifelong career. Her journey began in a small salon in Wailuku, a quaint town on Maui, Hawaii. Through dedication and skill, she earned her place at the prestigious Umberto Salon of Beverly Hills. For the past 11 years, Jennifer has operated her own private studio in Beverly Hills, serving a diverse clientele of celebrities, entrepreneurs, and professionals. 

A master of hair care, Jennifer specializes in styling, cutting, and color. Her greatest joy is making people happy, taking pride in ensuring her clients leave her salon not only looking good but feeling good. She cherishes the deep relationships she builds with each client, bringing warmth and artistry to every appointment.