Medically reviewed by Kristin Hall, FNP
Written by Our Editorial Team
Last updated 2/28/2021
Whether you’re struggling with male pattern baldness, stress-induced telogen effluvium, or diffuse thinning related to age, you are far from alone in your battle against hair loss.
Hair loss affects more than two thirds of all men by the time they reach thirty-five and, by the age of 50, roughly 85 percent of men experience hair thinning. Addressing hair loss can be tricky because there are so many different forms and myriad factors that come into play, but treatment options do exist!
If you’re not quite ready to make the jump into prescription hair loss treatments like finasteride or minoxidil, you may be considering a natural alternative.
From aloe vera and coconut oil to biotin supplements, saw palmetto, and even onion juice, hair loss remedies are a dime a dozen. One of the less “out there” options you may have come across is castor oil, a rising star in the world of natural remedies.
Though castor oil may be an up-and-comer in the world of natural health and beauty, it is by no means nothing new. Unfortunately, it may not be all it’s cracked up to be either.
In this guide, we’ll take a look at the science behind castor oil for hair growth. We’ll explore the research supporting this natural remedy and talk about the benefits castor oil may have for your hair. We’ll also cover how to use castor oil for hair growth.
Castor oil is derived from the castor (Ricinus communis) bean, typically produced by pressing the bean then purifying the resulting oil to remove toxic components like ricin and ricine.
This multipurpose oil has been used for thousands of years. In ancient Egypt, castor oil was used as lamp fuel. Medicinally, castor oil is commonly used as a stimulant laxative and, in homeopathy, it has been used to stimulate labor and lactation.
Today, castor oil is often used as an additive in food, pharmaceutical, and cosmetic products. It is also used as a component of biodiesel fuel and as an industrial lubricant.
Though castor oil is best known for its use as a natural laxative, it has recently gained popularity as a natural remedy for hair growth. Rich in ricinoleic acid, castor oil is purported to reduce dandruff, moisturize the hair and scalp, and increase the strength and flexibility of hair follicles.
But what does science have to say about it? Unfortunately, there isn’t any recent scientific evidence to show that castor oil promotes hair growth. That being said, castor oil has certain properties which may indirectly promote hair growth.
For example, castor oil is primarily composed of the fatty acid ricinoleic acid.
Oils play a significant role in protecting hair from damage, and some research suggests applying hair oil on a regular basis may enhance the lubrication of the shaft and help prevent breakage.
By preventing breakage, hair oils like castor oil may help healthy hairs grow longer.
Though castor oil may not be a miracle cure for hair loss, it may benefit your body in other ways.
Castor oil is made up of 90 percent ricinoleic acid, a monounsaturated fatty acid. Fats play an important role in keeping the hair follicles moisturized, healthy, and strong.
Ricinoleic acid acts as a stimulant on prostaglandin E2 receptors which plays a role in triggering blood vessel dilation. When applied to the scalp, castor oil could help increase blood vessel dilation in the scalp by boosting the flow of oxygen- and nutrient-rich blood to the hair follicles. Again, there is no current scientific evidence demonstrating this direct effect but anecdotal evidence exists to suggest castor oil may improve the growth or appearance of hair.
On top of consisting of monounsaturated fatty acids, castor oil offers antioxidant, anti-inflammatory, and antimicrobial benefits.
Castor oil also has the fat-soluble antioxidant vitamin E. And because of this help protect against oxidative stress which has been implicated in certain forms of hair loss, including alopecia areata. By reducing oxidative stress in the scalp, some research suggests supplementary vitamin E may improve hair growth in patients experiencing hair loss.
Vitamin E may also help lock in moisture on the skin’s surface on the scalp to promote hair health. By adding a protective layer of fat to the outside of the hair cuticle, oils that contain vitamin E (like castor oil) may improve shine as well.
Of course, we should note that in our research for this article, we couldn’t find any specific studies on castor oil and its effects on things like hair loss and hair shine — so, for now, take this as a mere “perhaps.”
Because castor oil isn’t a science-backed treatment for hair loss, there’s no right or wrong way to apply it.
The best application method may depend on your hair type and the conditions you’re trying to address. We recommend using cold-pressed castor oil — you can find it online or at your local health food store.
We also recommend doing a patch test by applying a small amount of castor oil behind the ear once daily for a week before progressing with an intensive treatment.
Here are a few suggested methods for application:
Fill a small bowl with castor oil and dip your fingers into the oil before gently massaging it into your scalp with your fingertips.
Work in sections, making sure to thoroughly coat each section with oil. When you’re finished, sit under a hair steamer to boost penetration. If you don’t have access to a hair steamer, simply let the oil soak overnight before washing.
To give your hair a deep-conditioning treatment, follow the method above to thoroughly coat the hair with castor oil before bed.
When you’re finished, put on a shower cap to keep the oil in place while you sleep. In the morning, gently comb your hair with a wide-toothed comb to work out any tangles before washing with shampoo and conditioner.
If you have fine, straight hair that is prone to tangling, you can use castor oil as a protective treatment before you shampoo.
Apply the castor oil sparingly to hydrate dry ends to prevent tangles. Simply dip your fingers in castor oil and work it gently into the ends of your hair by hand. Shampoo, rinse, and style as desired.
For wavy to curly hair, castor oil works well as a frizz-fighter, especially during the summer. Simply add a few drops of castor oil to your conditioner when you shower.
If you have tight curls or coiled hair, you may also want to use a little as a pre-shampoo treatment for added protection. When using castor oil as part of your regular routine, it is wise to use clarifying shampoo once a month to help rinse out excess oil so it doesn’t weigh down your hair.
Finally, remember that hair growth doesn’t happen overnight. Whatever treatment you choose, you’ll need to give it time to work. With FDA-approved hair loss treatments like minoxidil, you’ll need to use the product consistently for at least a few months to see any visible improvements.
For the most part, castor oil is generally recognized as safe but you should still exercise caution when using it. Castor oil has been known to cause adverse reactions such as diarrhea and allergic reactions in some people, so do a test patch before using it.
It’s important to remember that even if castor oil has the potential to improve the condition of your hair and scalp, it isn’t a medically proven treatment for hair loss. If you’re looking for a solution backed by science (and by the FDA), we recommend looking into finasteride or minoxidil.
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