By Jc of The Nat­u­ral Haven Bloom

So let us take a straw poll. How many of you have heard that cas­tor oil can help improve the thick­ness of nat­u­ral hair? I have seen this said many times, and since hair thick­ness is dic­tat­ed by genet­ics, I have always won­dered if there was any truth to the state­ment. I final­ly decid­ed to research it.

First question — what is in castor oil?

Like many nat­u­ral oils (coconut oil, shea but­ter, olive oil etc), cas­tor oil is com­posed of sev­er­al fat­ty acids. In real­i­ty, the­se acids are bound and there­fore do not real­ly behave like acids at all (note that you can­not pH an oil as it does not dis­solve in water). The dom­i­nant fat­ty acid in cas­tor oil is rici­nole­ic acid.

Can ricinoleic acid or any other of the fatty acids in castor oil increase hair thickness?

There are no sci­en­tific stud­ies to prove that cas­tor oil can increase hair thick­ness. Inter­est­ing­ly, in the field of male pat­tern bald­ness where hair thick­ness improve­ment is a major require­ment, cas­tor oil does not even fea­ture as a research ingre­di­ent.

What about the pictures where naturals show an improvement in hairline/bald patches by rubbing castor oil?

In my opin­ion this is not evi­dence because mas­sag­ing in itself even with plain water can stim­u­late regrowth of hair (i.e where hair has fal­l­en out or been pulled out, mas­sage can help a new strand to grow back). I would add though that the study that showed this was done in rats and not humans.

Addi­tion­al­ly, I have not seen any­one mea­sure the actu­al diam­e­ter of hair to show that cas­tor oil use has thick­ened their hair. Some peo­ple refer to thick­ness as the over­all den­si­ty of hair and in my view again this is not proven by the pic­tures as often they are just refer­ring to nor­mal regrowth.

Could something else be at work?

My the­o­ry in dis­cus­sion with my chief chemist (i.e the hus­band) is that cas­tor oil per­haps can stick to hair more firm­ly than most oils and there­fore cre­ate an illu­sion of thick­ness. Any­one who has used it will note how thick and vis­cous it is. It is almost like a soft glue and tends to stay put and not move when applied. It does not trans­fer eas­i­ly either, which means that it can attract small par­ti­cles of dust and lint which may also add to the illu­sion of thick­ness.

Do you really need to change your hair thickness?

In my view, I think that life and biol­o­gy is about diver­si­ty. Not every­one can have thick hair strands, not every­one can have high den­si­ty hair but every­one can have great hair regard­less of how thick the strand or how dense the hair.

Ladies, do you use cas­tor oil? Has it help improved thick­ness?

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79 Comments on "Does Castor Oil Increase Hair Thickness and Rejuvenate Edges?"

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I am a black cas­tor oil advo­cate. I pri­marly use it on the ends of my hair and to seal in mois­ture; it works won­ders again­st sin­gle strand knots. Not sure about it mak­ing my hair thick because my hair is already thick. But I love that cas­tor oil goes a long way, you don’t have to use a lot.

Rachel Natalie

Yes, I love cas­tor oil for seal­ing. It agrees with my hair and ends.


Cas­tor oil is the best for seal­ing my edges and ends.




I can under­stand where cas­tor oil would cause a buildup of par­ti­cles that would mim­ic thick­ness of the hair. I would not use it because of that. I like to use light and non greasy hair prod­ucts for my hair, espe­cial­ly in the sum­mer and also use a puri­fy­ing sham­poo and con­di­tion­er. Thank you for this infor­ma­tion :)


This is inter­est­ing, I was won­der­ing about Cast­er oil, had it on my list of things to try. My sweet­ie left some Jama­cian Blask Cast­er oil at my house on acci­dent and he lives out of town so.… I’m gonna start using it in the oil com­bo I use to mas­sage my scalp with and see if I notice any dif­fer­ence in my growth/thickness.




Inter­est­ing i guess Cas­tor oil­does some­thing even if scince doesn’t want tore­search it or val­i­date it. Sci­ence is what it is knwledged but when it comes to hair jour­neys i’m afraid it’s about an idncid­u­als expe­ri­ence.

I love cas­tor oil it is bril­liant added to a deep cond­tion­er and a great source of mois­ture.


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Love this picture!!!You’re one pret­ty lady.It is encour­ag­ing to see such good hair growth and it is nice that cas­tor oil has worked so well for you!


I have been using Cas­tor oil for the past year (pic right after­BC on 9/10 and now) and I most definet­ly believe that its had an effect on my hair growth and thick­ness.. I Love It!



My expe­ri­ences with cas­tor oil have been very reward­ing. My hair has been soft­er and thick­er to the touch <3

Tiffany Madonia

Well, I’ve used Jamaican Black Cas­tor oil on my edges…there were two par­tic­u­lar spots where my hair was not grow­ing at all any­more for like 3 years, due to braids that were too tight. I used the JBCO and my hair start­ed back growing.…I stopped using it and the hair growth stopped (the hair that had grown did not fall out though).


Hi well for me per­son­al­ly I have suf­fered with a hair­line prob­lem after repet­i­tive times plac­ing my hair in a tight bun or pont tail. A year ago I start­ed to mas­sage the area and a year lat­er i have seen a vast improve­ment.