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Castor Oil For Hair: What It Is & How It Works

Updated: Apr 7, 2021

This topic was suggested by reader Jess. Check out her blog Cook with Jess here!

Enjoy this read and, as always, click the numbers in square brackets to check out all the references!

What is castor oil?

Castor oil is a vegetable oil that gets pressed from castor beans into a yellow liquid [i]. It gets used to make soaps, polishes, inks, pharmaceuticals, creams, make-up, and a bunch of other stuff.

Castor beans originally come from tropical regions of eastern Africa but are now grown in many tropical and subtropical places [ii]. There is evidence that ancient Egyptians used castor oil to burn in their lamps and as a skin salve [iii].

In regards to hair, people usually use it as a hair conditioner and to help promote thicker hair growth. Thickening eyelashes and eyebrows is a common use of castor oil. Castor oil for beard growth has also become more popular with the facial haired community.

Two kinds


Cold-pressed castor oil is made by crushing castor beans and seeds in a heat-free and chemical-free process. The oil you get from this process is light yellow.

Castor Seeds

Jamaican Black Castor Oil

This oil is made by picking the beans, drying them, roasting them, making them into mulch, and then pressing out the oil. This is why the oil comes out much darker than cold pressed oil [iv].

This use of castor oil is an important part of Jamaican history as it was brought by people stolen and forced to become slaves in the Caribbean. It is a part of Jamaican cultural heritage and has long been commonly used for skin and hair [v].

Castor Bean Plant

What is the difference between them?

The only difference I could find between the two of them was personal preference. Both oils contain the same chemical properties so I don’t see there being a major difference between the two of them.

Does Castor Oil Work

Castor oil is made of 90% ricinoleic acid [vi]. Ricinoleic acid studies show it may stop hair loss by blocking a protein called prostaglandin D2 which is associated with baldness [vii].

Castor oil for dandruff treatment is another benefit. Ricinoleic acid has been proven to be an anti-inflammatory [viii, ix]. Since there are certain types of dandruff that occur from inflammation of the scalp [x] it is likely that the use of castor oil will help treat those types of dandruff.

I wasn’t able to find any scientific evidence that use of castor oil either grows hair better or thickens your existing hair. There has been lots of anecdotal evidence that it does though which means you may still have success if you try it!

Is it safe

I couldn’t find studies that showed any dangers associated with use of castor oil. I would recommend that if you want to try it you use a little swatch on your arm and leave it for a day to see if you have an allergic reaction.

What to pair it with

If you are interested in using a combination of oils I would suggest castor oil and coconut oil for your hair. Both have similar benefits and are often paired together in homemade hair mask recipes. I will try this myself and let you know how it goes! Click here to read more about how coconut oil benefits your hair.

My thoughts

The science seems to support that castor oil is very moisturizing to hair and helps reduce hair loss. I also like that as an oil it is nontoxic, biodegradable, and a renewable resource [xi]. I would look for ethically produced oils because there can be exploitation of workers and producers by larger companies.

There are a number of Jamaican black castor oil producers that are black owned so make sure you are buying from them and investing in smaller businesses!

I would recommend buying a product that comes in an amber glass bottle because it protects the oil from light and glass is better for the environment than plastic.

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