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

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[…] the scalp works well as the second step after you apply your regular moisturising spritz. Note that castor oil is quite heavy so concentrate it mainly on your hairline or dilute it with a few lighter oils […]

The best oils to regrow hair is castor and emu oil, they are the two only oils that penetrates further into the skin and is able to activate the follicles (besides some essential oils like tea tree, but those need a carrier oil and can irritate your skin if you use too much by itself). When you use castor or emu and mixed it with essentials oils too, it works even better. You can make your own oil blends with castor oil, or buy a readymade blend. One great vendor is cnsciousessence. com. Another tip, spray your edges and parts… Read more »

how about someone would test under microscope, like see the porous damaged hair before and after? in india castor oil is number 1 hair product, i dont know why, i only enjoy it when i apply night before hair wash, then i wash my hair in the morning and i like the result


Castor oil has anti-fungal properties, as does tea tree oil, which helps with hair growth. This is why women are also using Monistat cream on their scalp for its anti-fungal chemicals that assist with hair growth and other scalp issues (dandruff,etc.). There is scientific evidence.

Try the Castor oil ladies and add tea tree oil and peppermint oil(increases blood circulation) to the mix if you like. They work.


I use raw castor oil, not the store bought stuff. In the caribbean they sell huge bottles at the market its usually dark brown almost black and stinks but that’s why its so good.

Alot of women use store bought oils that are nowhere close to the natural stuff.


The clear yellowish castor oil is natural. Black castor oil is dark because ash is added to it. Castor oil is not naturally black.

Charlette Hernandez

I just purchased it and I believe it works and I am gonna use it.


How has it been working for you?

deepali kamre

due to teh typhide i lost my hair my hair became very thin & dull, kindly suggest me something for hair thickness & hair growth my mail id is mentioned above please suggest

Kimberly Diei

Can any type of castor oil be used? In the grocery store they sell it as a stimulant laxative but it says it is cold pressed. Is this type okay to use on hair?


Can castor oil make my hair straight?


I have been using castor oil for so many years. It works really good. It makes hair thick and keeps scalp healthy. Tryout and experience the change. No Other oil make your mane thick in just 1.5-2 months except the castor oil. Don’t wash your hair daily, it could make your hair to fall. If you wanna go out just cover your hair with scarf, as it protects your mane from sun and dust. I do the same. Apply castor oil thrice in a week.


What kind of castor oil do you use? do you have to use JBCO or can Cold Pressed work?


Going to get my hands on that scalp massager, because I’m just too lazy to put my hands up for too long, but you sure it won’t get all nitty gritty and personal with my hair? I’ve been using JBCO and so far, so good. I think its a GREAT sealant and I used it to massage my edges as they’re also pulled out thanks to braids and wigs with combs.

I had male pattern baldness, pretty severe actually because I was totally bald by the time I was 30.. tried everything in the book (rogain, propecia, hairmax comb etc to name the least), nothing worked more than some peach fuzz… Then my wife told me how well castor oil was working for her lashes. SO i decided to use it.. every night, I would wet my head with water a little and put pure castor oil on (around a tea-spoon full) and go to sleep, next morning would take a shower (was sure to put thick piece of cloth so… Read more »

lol they kinda bash it. It works for me! Made my edges flourish. I think my hair likes it. 🙂


i had a small bald spot at my right temple due to tight braids. i massaged that area w/castor oil & the hair grew back nicely.


I understood fine thank you understand by my statement.

I don’t massage my scalp at all & castor oil still works for re-growth/thickness and more than avg growth & this has been true for many others–scientific backing or not.

The AlizTube

A HEAD MASSAGER. In case you don’t feel like keeping both arms up.

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I live in the UK so it costs 99p … so just over a dollar maybe…

The AlizTube

Sorry about the HUUUUUGEEEEE pic!!! I was not expecting that!!! lolz


This is disappointing news. I have been searching for products to get back the fullness I had prior to weave damage.

The AlizTube
Hey hun, there aren’t any products that will do that unfortunately. Its all about taking good care by nourishing the hair by washing with shampoo or conditioner, applying a hair cream (optional) and sealing with oil on a consistent basis. I do this every ten days. A good massage every now and again helps to stimulate the blood vessels in the scalp. The more you massage, the more it is likely to stimulate growth. Cos I’m lazy I get my boyfriend to do it properly once a week. Then on wash day I do another light massage in the shower.… Read more »
After, reading all the comments, testimonies and unofficial research on rather or not Jamaican Castrol Oil really thickens the hair or aids in hair growth, I have decided that I will continue purchase Jamaican Castrol Oil because most of the users seem to benefit from its use. I am sure rather or not it does what the maker of the products says it does. However, what I am sure of is that the users feel they benefit from the use of Jamaican Castrol Oil. As new consumer of Jamaican Castrol Oil (Two weeks use) I cannot attest to rather or… Read more »
Shani Jackson
Well I can say that I have been using Jamaican black castor oil and my hair has thicken up tremendously. I have been using it for 1 month and I could not believe what I have been seeing. Of course I wear protective styles because I do not like combing my hair every day. I have kinky coarse hair. It is shoulder hair. I wear faux bun with synthetic hair you tube inspired and I wash my hair once every two weeks. Also I use Jamaican black castor oil every other day. My hair is soft and moisturized. Try it… Read more »
I’ve had natural thin and fine hair my whole life and I don’t see how an oil can change the thickness of each individual strand when its already pre-determined. I’ve used castor oil and you know what it did for me? Left my scalp greasy and that’s it. As for women who said it regrew their edges, have you ever taken into consideration that its not the oil per se but rather your new techniques and the way you care for them now i.e…. “babying your edges”. If you believe castor oil thickens hair than by all means disregard this… Read more »
Jo Somebody

100% truth!


I swear by Black Jamaican Castor Oil. My scalp loves it and I notice that it promotes hair growth for me.


Less manipulation of your hair seems to help more than any product. The less stress you put on your scalp and hair follicles seems to help it repair itself. When I leave my hair alone, it seems to grow better. Castor Oil is a just a moisturizer to me definitely not a hair growth product.

I think everyone here has more or less MISSED the point of this article. It was to illustrate the effects of MASSAGING the scalp, rather than a reliance on product. With consistency (in terms of hair) in technique, results are always seen. We speak of having a regime and talking about how products sometimes are not the factor of growth but how it is used in your technique. The responses seem like everyone is suggesting that castor oil is a type of miracle cure-all, growth aid/thickener. This is not the case, it is the act of how it is used… Read more »
Southern Girl

Hmm I’ve never really massaged it in. Just used it in the leave in and to moisturize my scalp from time to time. I’ll see how the massaging works if I can remember to be consistent with it but I did get much thicker over the last year sans massage.

Jo Somebody

And NOTHING else changed in how you treated your hair over that year?

Lol I won’t say that I just rely on massages, of course I have a routine pretty much the same one since january (usually : I wash at least once a week (max 10 days) before the wash I pre-poo, once a month usually I make a rhassoul clay mask, I use water or natural gel as moisturizer followed by oils or butter mixes to seal and that’s it). I’m huge fan of mini twist and mini braids too (I tend to neglect my hair, when it’s out for too long). To me the whole lead me here, it’s no… Read more »

Oops I thought the question was for me XD forget it

The AlizTube

No, I just massaged my head. 🙂

Give it a try I know many have no spare time but try to get 5 to 15 minutes a day to do some (while watching some movie or while surfing on internet, even while talking with friends). I’m not a scientist so I’ll try to explain it with my own words (plus I’m a french speaker so it might not sound clear but) it stimulates blood circulation which I guess means an improvement/increase in the transport of oxygen and nutrients to the scalp. Nutrients and oxygen play a role in the making of a strand. By increasing or fastening… Read more »
I agree ! I swear by massages all day errday I’m a huge fan and without using oil except when I pre-poo and I don’t really focused on putting it on the scalp. I do use castor oil because it does no harm but nothing to rave about just a good oil better for me when mixed with other to make it lighter and that’s it. My hair growth is good and consistent I guess due to massages and with PS I manage to retain it . Here 2 pictures one of summer 11 the other summer 12 : [img[/img]… Read more »

I use castor oil for moisture retention in the winter time I think it a better barrier for the dry winter air and the even drier heaters indoors during that season. It also provides excellent hold and sealing qualities during the other seasons.


My hair hates pretty much everything. But, castor oil mixed with my organix coconut milk it LOVES (on damp hair)…..i bought the bottle pictured in the artile BUT I HATE THE WAY IT SMELLS……They sell castor oil with no smell in walmart and PERFECTION…….And I repeat my hair hates EVERYTHING but this….

Southern Girl

I am not sure about anyone else and it definitely didn’t happen overnight but I use JBCO in my leave in and in an oil mix. I use the leave in consistently and the oils not so much but my hair last August to this August is a lot thicker, healthier, and has a much better shine. I don’t use much on the hair shaft as much as I do my scalp beyond the leave in. It’s never felt heavy unless I was using too much.


what i like most about castor oil is that it lays my hair down. Its a heave oil(for my hair) and weight it down! i like it.


I can’t say it has made my hair thicker because I never monitor the thickness of my already really thick hair and the oil itself is VERY thick. I just like it as part of my leave in conditioner mix.




Oh, that’s nice. Thee are hundreds if not thousands of women of all ages and races on youtube & various message boards that have had success with castor oil in terms of more than average growth and thickness.

Reminds me of scientists claiming for eons that chicken soup for a cold was just an old wive’s tale and lo and behold after actual studies researches found that Chicken soup, prepared with a variety of vegetables, inhibits a process that leads to the respiratory symptoms seen with the common cold.


What u said was soooooooooo right mate..

Hmmm I think there is a little misunderstanding here due to terms. In this case she is talking about actual thickening of a hair follicle to be thicker than it was genetically predisposed to being. Nothing can change that to date or else fine haired naturals would be all over it. What you and others are describing as “thickness” (as she has mentioned in her post as well) is the regrowth of hair that may have been stunted or otherwise. That’s an improvement in density i.e. amount of hair and not strand thickness. There doesn’t appear to be an actual… Read more »

I dont massage my hair in any way and it grows…castor oil works.


JBCO is awesome for sealing in moisture. I use it to seal my ends which has helped with length retention. Rubbing it along my thinned temples has rejuvenated growth in those areas which never happened when I used straight coconut oil or Jane Carter scalp nourishing serum.


I currently have been using Oyin’s Handmade Burnt Sugar Pomade, in which Castor Oil is the first ingredient, on my “spacey edges”. I’ve been watering my edges (moisture) and then applying the pomade (sealing) to them twice a day for the last 6 weeks or so and I have had great results! I think Castor Oil is a great sealant and because of that it protects properly moisturized hair and allows for length retention. Check out my post about my “Spacey Edges” Challenge here —>


I have an eyebrow that won’t grow (all the way to the end/length of the other one) and the indian lady who threads them for me told me to use castor oil to make it grow. It did work for growing the hair but my hair is already thick so I don’t know if it did anything for the thickness.


my indian friend and the girl who threads my brows both suggested castor oil for brows too.

I believe castor oil works. I gave my SIL qhemets amla cream which has a lot of castor oil. Next thing I hear is that my brother has had to start going to the barber more frequently after he started using it and had to ditch it because of that. He’s a guy and doesn’t massage his hair or do any special treatments. (unless applying the product counts as massaging?) and the qhemet product was the only thing he changed. I’ve also used castor oil on its own (I discovered that avocado oil works too) to grow in my eye… Read more »

jbco has helped my hair. i mix it with olvie, coconut and tea tree oil. i used the lavender jbco and my edges are very full now, now that they were thinning out but the jbco mix i use really helped with keeping my edges and ends moisturized.


*not that


I think it grows and protects but not add thickness. Really protective in the winter


I have use castor oil on my edges for approx. 2 1/2 years and I have noticed a vast improvement in the growth of my hair. My hair loss was due to improper use of relaxers, pulling my hair too tight and sulfate shampoos. I have eliminated the relaxers, braids and sulfate shampoos and I do believe the castor helped to regrow the hair that I lost. I also use it to seal my hair after applying moisture. It is worth a try and it far more affordable that some other alternatives out there. 😉

“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.” this statement means nothing. i’m a lover of natural foods and believe that a whole foods approach to living makes eliminates many maladies. up until recently, the “scientific” community dismissed this form of thinking. absence of studies or certain things not being studied means little to me in light of said perspective on food and health. you’ve drawn conclusions based… Read more »
I agree with Merry. My boyfriend is a scientist, and he likes to proclaim the superiority of science. But I believe that history itself has proven that science is not the end all, be all. Remember when we all thought Pluto was a planet? That was “science” until, well, it wasn’t. I also agree with Merry’s point about the whole foods movement not being recognized by the medical establishment. Watching documentaries like Fat, Sick and Nearly Dead and The Gershon Miracle have helped me to realize that, just like anything else, science and medicine are inundated with biases and traditions… Read more »

*negatively affect


co-sign! she’s saying there’s no studies to prove the benefits, so how can she conclude that it doesn’t do anything? contradiction much?


I tried castor oil one time on my fine hair and it felt like it was stuck to my hair, like a really tacky feel but I want the benefits so I will try again lol


Dilute it with a lighter oil such as jojoba, coconut, argan etc. and it will distribute better and not feel so heavy on your strands.


I completely agree. Try the product in this link

I wonder if there is a difference between using castor oil and jamaican black castor oil. I know that the process of creating jamaican black castor oil is vastly different than just regular castor oil because they slow cook or burn the seed. This might infuse some sulfur into the oil that could help with hair growth (MSM is the sulfur that i believe is in a lot of hair growth supplements that actually work but i could be wrong). I have never used regular castor oil but I swear by Jamaican black castor oil and incorporate it faithfully into… Read more »

I don’t know if it rejuvenates your hair or not…BUT have I noticed a difference in using castor oil?

YES!!! Water (for moisture) and Castor Oil to lock it in and I’ve seen my hair flourish. It’s amazing.

I use the castor oil pictured above. I just purchased a new bottle of it. I hope to use JBCO one day.