Benefits of Castor Oil for Hair

Castor oil is a thick, nutrient-dense oil extracted from the seeds of the Ricinus communis plant. The oil is chemically unique, composed primarily of the fatty acid ricinoleic acid, which typically constitutes about 85% to 95% of its total composition [4]. This high concentration of ricinoleic acid, a type of omega-9 fatty acid, is believed to contribute to its soothing and moisturising properties.

How is Castor Oil Useful?

Castor oil is widely believed to support scalp health, enhance moisture retention, and improve hair texture. While clinical evidence that it directly accelerates the growth rate of hair is limited, it is beneficial for creating a healthier scalp environment conducive to growth. This is achieved by locking in moisture, and its unique chemical structure allows it to potentially strengthen hair strands, which may prevent breakage.

Potential Benefits of Castor Oil on Hair

1. May Provide Anti-inflammatory Effects

Castor oil contains ricinoleic acid. This compound has been studied for its anti-inflammatory effects [3]. When applied topically, this may help decrease irritation on the scalp, which if chronic, can sometimes inhibit optimal hair growth.

2. Nourishing and Strengthening the Scalp

The oil is rich in essential fatty acids, vitamin E, and antioxidants, which may help nourish hair follicles and enhance scalp health. This contributes to hair that feels stronger and appears more resilient. Castor oil also functions as an occlusive, meaning it helps seal in moisture and prevent dryness, particularly along the hair shaft.

3. May Support Hair Growth by Reducing Breakage

While often credited as a direct growth stimulant, the main way castor oil appears to ‘promote hair growth’ is indirectly. The vitamin E and fatty acids in the oil help strengthen the hair fiber and root anchorage, which reduces the likelihood of the hair breaking off before it reaches its full length [1], [5]. By improving the health of existing hair and reducing its fragility, users perceive thicker, faster-growing hair.

4. Helps Manage Mild Dandruff

Castor oil possesses certain antifungal and antibacterial properties [4]. Due to this reason, it may help address mild scalp flaking associated with certain fungal overgrowths by killing the microorganisms that cause dandruff and other scalp infections. It can soothe itchiness and flaking, although it should be noted that it may not be effective for chronic or severe dandruff that requires medicated shampoos.

5. May Prevent Hair Loss by Improving Strength

Since castor oil has strengthening properties that reduce hair breakage, it prevents further structural hair loss. This is crucial for individuals with dry, brittle, or chemically treated hair that is prone to snapping. It is not a scientifically proven treatment for pattern baldness (androgenetic alopecia) or other serious forms of medical hair loss.

6. Provides Thicker-Appearing Hair

While users may observe hair appearing thicker due to the coating effect of the thick oil, increased moisture, and reduced breakage, it is important to clarify that no clinical studies confirm that castor oil significantly increases the number of hair follicles or the diameter of the hair shaft (true hair thickening).

7. Adds Natural Shine

Castor oil’s moisture-sealing ability can help smooth the hair cuticle, making hair look shinier and less frizzy. Its occlusive nature creates a reflective surface, enhancing the appearance of shine.

8. Prevents Hair Breakage

By locking in moisture and improving hair elasticity, castor oil may help reduce breakage and improve hair texture, especially in dry or curly hair types. Its humectant properties may attract water into the hair shaft, helping it stay hydrated and strong.

9. Beneficial for Eyelashes and Eyebrows

Castor oil is often applied to eyelashes and eyebrows with the hope of encouraging thickness. While it may help by moisturising hair and reducing breakage, there is no scientific consensus that castor oil can directly stimulate lash or brow growth. Use near the eyes must be done with extreme caution to avoid accidental contact with the eye, which can cause irritation [4].

What Are The Types Of Castor Oil?

1. Cold-Pressed Castor Oil (often labelled ‘Organic’)

It is predominantly used for hair and is a good general-purpose oil. A natural moisturiser, it cleanses hair and skin. It is processed without heating and extracted directly from castor seeds, retaining the highest level of nutrients.

2. Jamaican Black Castor Oil (JBCO)

It is most commonly used for scalp-related issues. It is formed by roasting castor seeds and then boiling them before extraction, which results in a darker colour due to the ash content. It is traditionally absorbed by hair easily and has a higher pH, which some believe opens the cuticle better.

How Do I Use Castor Oil?

Castor oil itself is a very thick and sticky oil. The direct application makes it difficult to spread the oil through the hair and scalp, and difficult to remove.

It is strongly recommended to dilute it before application, either with a lighter carrier oil like coconut oil, jojoba oil, or olive oil. Castor oil has a characteristic scent, which is unpleasant to some people. Diluting the oil with other oils also solves this problem.

Castor Oil with Coconut Oil

Coconut oil, similar to castor oil, is highly rich in fatty acids. This also helps strengthen and enhance hair resilience. It helps the mix go deeper into the hair cortex and cuticles.

• Mix two tablespoons of castor oil with two tablespoons of coconut oil in a bowl.
• Massage the mixture on your scalp for five minutes.
• Apply it from your roots to your ends.
• Cover the head with a shower cap or towel and keep it for at least two hours or overnight.
• Wash off with lukewarm water and shampoo.
• Use this method no more than twice a week for a limited duration.

Important Note on Duration:

It is strongly advised to limit the use of heavy oil treatments like castor oil to short periods (e.g., 6 to 8 weeks) to prevent excessive buildup. Longer use of castor oil may increase the risk of a rare condition known as acute hair felting (see side effects below) and may clog hair follicles in sensitive individuals.

Potential Side Effects and Safety Precautions

Castor oil side effects are usually very rare with topical use. But since excessive use of it can cause serious complications, it should be used with precautions.

Acute Hair Felting

The most serious side effect is acute hair felting, a rare, irreversible disorder where hair becomes spontaneously matted and tangled into a hard, dense mass, often requiring the affected portion of hair to be cut off. While the exact cause is complex, overuse of thick oils, including castor oil, combined with aggressive washing techniques, can be a contributing factor.

Other Side Effects

• Avoid ingesting castor oil, it is a powerful laxative and can cause severe stomach upset, dizziness, and other side effects when taken orally.
• Always do a patch test (on a small area of skin like the forearm) before applying to the scalp to avoid allergic reactions or irritation.
• Buildup: Due to its thick nature, overuse can lead to heavy buildup on the scalp, which can clog pores and potentially hinder hair health.

Frequently Asked Questions (FAQs)

Which is the best type of castor oil for my hair growth?

Cold-pressed castor oil is the purer form and is generally recommended. Jamaican black castor oil is often preferred for scalp-related issues due to its traditional use in haircare, but both types share the same main beneficial component, ricinoleic acid.

How often should I use castor oil on my hair?

Use no more than twice a week, and it’s advisable to limit the treatment to 2 months at a time and then take a break to avoid buildup or the risk of hair matting/felting.

Does castor oil help your eyelashes grow?

There is no scientific evidence that it directly promotes eyelash growth, although it may reduce breakage and improve lash appearance by moisturising the lashes.

What precautions should be taken while using castor oil on eyelashes?

Use only a sterile applicator (like a clean mascara wand), never double-dip, avoid getting the oil into your eyes, and remove it carefully with a gentle cleanser to avoid irritation or infection.

Castor oil works well with?

It blends well with lighter carrier oils like coconut oil, jojoba oil, and olive oil for enhanced moisturising effects and easier application.

Disclaimer:

This article is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified healthcare provider or dermatologist with any questions you may have regarding a medical condition or before starting any new hair care regimen, especially if you experience persistent scalp irritation, hair loss, or have a pre-existing condition.

References

[1] Tiwari, R., Tiwari, G., Yadav, A., & Ramachandran, V. (2021). Development and Evaluation of Herbal Hair Serum: A traditional way to Improve Hair Quality. The Open Dermatology Journal, 15(1), 52–58. https://doi.org/10.2174/1874372202115010052

[2] EXTRACTION AND PURIFICATION OF CASTOR OIL FROM CASTOR SEEDS TO STUDY ITS NUTRITIONAL AND BIOMEDICAL IMPORTANCE. (2025). Thermsr.com. http://www.thermsr.com/index.php/Journal/article/view/400

[3] Parsons, C. (2024, December 21). Best oils for hair growth. XYON. https://xyonhealth.com/blogs/library/best-oils-for-hair-growth

[4] Alookaran, J., & Tripp, J. (2022). Castor Oil. PubMed; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK551626/

[5] Patel, V. R., Dumancas, G. G., Viswanath, L. C. K., Maples, R., & Subong, B. J. J. (2016). Castor Oil: Properties, Uses, and Optimization of Processing Parameters in Commercial Production. Lipid Insights, 9, LPI.S40233. https://doi.org/10.4137/lpi.s40233