Is Castor Oil the Key to Hair Growth?

Julia Bergh
Jun 9
4 min read

Hair specialists provide insights on the miraculous component.

If you are frequently online, particularly as a regular viewer of #HairTok, you have likely encountered numerous videos discussing components such as rosemary oil and Amla oil, which extol their alleged benefits for promoting hair development in oils and masks. Among all these popular nutrients, one steadfast element persists in the discourse on hair growth: castor oil. This enduring treatment has been integrated into the practices of generations and is likely a recognized component of your hair care regimen.

Nikita Mehta, co-founder and creative director of the ayurvedic haircare brand Fable & Mane, states, “Castor oil is the oldest and most renowned herbal remedy for hair oiling.” It is abundant in fatty acids such as ricinoleic acid, rendering it highly viscous, nourishing, and hydrating. It has been demonstrated to envelop the hair shaft, mitigating damage and promoting longer, stronger growth.

With 566 million views associated with #castoroil on TikTok and over 258,000 posts on Instagram, people assert that the oil enhances hair shine and bounce while promoting thickness and length. Are these assertions legitimate? We consult three specialists regarding the advantages of castor oil and its precise application methods.

What is castor oil, and what are its advantages?

Castor oil, scientifically referred to as Ricinus communis, is a nutrient-dense vegetable oil derived from castor beans. Despite its origin in tropical East Africa, it is extensively utilized in India and the West Indies for cosmetic and therapeutic applications. Castor oil is typically transparent or pale yellow, except when produced through roasting or boiling, resulting in black castor oil.

At the molecular level, castor oil consists of long-chain fatty acids. “Fatty acids supply vital proteins and nutrients to hair follicles and mitigate follicular inflammation,” states Bridgette Hill.

In addition to its anti-inflammatory qualities, castor oil possesses several other significant attributes. Dr. Hill states that the advantages of utilizing castor oil encompass enhanced luster of the hair, improved flexibility of the hair shaft through coating, and the provision of antibacterial characteristics.

Does castor oil promote hair growth?

Dr. Hill states, "No studies demonstrate that castor oil can enhance hair growth beyond 1 cm per month, which is the FDA's criterion for hair growth." “Nevertheless, patients frequently convey differing perspectives to me.” Ninety percent of castor oil consists of the fatty acid ricinoleic acid. It is recognized for its ability to activate the Prostaglandin E2 receptor, resulting in vasodilation. Application to the scalp enhances blood vessel dilation, so augmenting the supply of oxygenated and nutrient-laden blood to the dermal papilla, the hair follicle's essential component.

Bridgette Hill concurs that castor oil indirectly improves hair growth. “Due to the nutrients in castor oil, it safeguards the hair follicle from external cellular and tissue intruders that compromise the health and vitality of the follicle.”

Is castor oil safe for application on eyelashes and eyebrows?

The succinct response is affirmative regarding the eyebrows, but exercise caution with the eyelashes. Dr. Hill states, "If patch testing reveals no allergy to castor oil, it is safe for use on the eyebrows." There is a lack of safety data on castor oil and ocular health; thus, I advise exercising caution and seeing an ophthalmologist before putting castor oil near the eye.

What is the method for applying castor oil to the hair and scalp?

Despite its widespread usage, castor oil is not suitable for all individuals. Consequently, doing a patch test prior to application on the scalp is essential. “Administer a modest quantity behind the ear or on the inner upper arm for one week,” advises Dr. Hill.

After confirming the compatibility of castor oil with your scalp, the subsequent step is to choose the appropriate quantity. “Hair oiling is effective for all hair and scalp types; however, the efficacy depends on the specific formulation of the ingredients,” states Mehta. Her guiding principle: the greater the purity of the oil, the denser it will be. Dr. Hill elaborates further here:

Fine to medium straight hair: Castor oil serves as a deep treatment to safeguard the terminal two to three inches of your hair fiber. It may also serve as a pre-shampoo treatment to prevent tangling. Exercise moderation; cleanse your hair thoroughly with shampoo and style it according to your preference.

Medium to thick straight or wavy hair: Administer uniformly throughout the entire scalp for a potent pre-shampoo therapy. Apply heat or steam to facilitate deeper penetration into the hair cuticle.

For wavy to loose curls, I recommend incorporating drops of castor oil into conditioners during the hot and humid summer months.

For curly to tightly coiled hair, I recommend use castor oil as required during your regimen, whether as a pre-shampoo treatment, an additional treatment, or a weekly moisturizer. Conducting a thorough monthly detoxification shampoo is imperative when utilizing dense oils such as castor oil.

What is the optimal method for utilizing castor oil?

The optimal method for using castor oil is on dry hair and scalp. “Initially, warm the oil between your palms, then apply it to the roots and massage into the scalp, concentrating on the crown chakra (the apex of your head) to alleviate tension and stress,” Mehta advises. After distributing the excess throughout the lengths of your hair, let it to remain for 20 minutes or overnight. “Thoroughly rinse with lukewarm water and subsequently shampoo.” Double cleansing may be necessary to eliminate all remnants of the oil, and I typically forgo conditioner following hair oiling, since the oils offer ample hydration. You will observe an improvement in hair hydration, and with constant application, you will experience increased length and volume of hair growth.

Which variety of castor oil is optimal for use?

All of our hair specialists endorse cold-pressed castor oil.

Dr. Hill states that cold-pressed castor oil can be applied to the hair shaft. Mehta characterizes it as having a pale gold hue, noting that due to the viscosity of castor oil, which can adhere to hair, it is advisable to dilute it with a lighter carrier oil, such as coconut or almond oil.

Dr. Hill advises that black castor oil should exclusively be administered to the scalp. After applying black castor oil to the hair, a cuticle-sealing procedure should subsequently be employed. Both versions will supply adequate components of ricinoleic acid.