I do regularly contribute science articles to BGLH and I am cross posting this one because the question comes up time and time again.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 from a scientific perspective.
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. Many of the other fatty acids in castor oil are similar to those found in coconut or olive oil and these are not associated with increasing hair thickness either.
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 .
Do you think that castor oil can thicken hair? What is your experience with it?
Thanks for posting this!
ReplyDeleteThis was a very interesting read! I've always been under the illusion that castor oil makes your hair thicker but what you have explained makes a lot of sense.
ReplyDeleteI consider myself newly natural (no relaxer in a few years but just since June with no heat styling). I'm enjoying learning my hair and seeing it respond to more TLC. I love your site, your knowledge and the science behind your posts! I just read much about castor oil thickening hair and causing regrowth. The castor oil mentioned specifically to do this is Jamaican black castor oil? Is its makeup the same as traditional castor oil? Might that be the difference?
ReplyDeleteGood question! From the research I did, I found that the chemical profile of Jamaican black castor oil is not really prominent.I did find one paper with crude Malaysian castor oil (which is similar to unrefined Jamaican black castor oil. The likely reason for the colour is actually iodine which is removed in refined clear castor oil.
DeleteIodine intake in food (not castor oil which is not recommended) is useful for maintenance of skin and nails. I have not seen it related to thickening of hair though (I will check some more later this week though)
The paper reference for the Crude castor oil is - Sains Malaysiana 39(5)(2010): 761–764
Thanks for the explanation!
DeleteThanks, jc, for the reply! I'll wait for your further research before investing in Jamaican black castor oil.
ReplyDeleteoften times like you said we misuse thickness for hair density, when we say thick we mean hair density lol i also think that massaging the hair is supposed to bring nourishment from the blood to the hair follicles so probably the action accounts for the increase in hair growth
ReplyDelete@Anonynous & Jc, I was about to mention Jamaican castor oil as there is a difference in the formulation, But as you mention that you will look into that.
ReplyDeleteOne other question, is in regards to Jamaican Black Castor/Castor promoting 'Hair Growth', promoting faster 'regrowth, what is the real science behind this. Sorry if you have posted it in the past and I have missed it >.<.
Keep up the awesome work you do here :).
Thanks for the compliment. No, I have not written anything about castor oil and promoting faster regrowth. I did a search on what can accelerate hair growth and the results are here -
Deletehttp://www.thenaturalhavenbloom.com/2009/06/hair-growth-myths-miconazole-birth.html
good post
ReplyDeletecb
What I heard is that castor oil strengthens hair strands. I also believe that there's a degree of truth to this, from my experience.
ReplyDeleteWhat do you say about this?
I think that if there is a strengthening effect it is temporary, in the same way most products work. For example protein conditioners will temporarily strengthen hair, coconut oil will temporarily prevent breakage i.e only during the wash and immediately after, hair conditioner helps to soften hair temporarily.
DeleteI think that products including oils like castor oil can help us manage our hair but ultimately it is how gentle you are physically that makes all the difference.
I believe that the rubbing motion and the oil can stimulate dormant follicles and therefore when there is new growth your hair appears thicker.Now i have no scientific sources to provide proof this is just a thought. :)
ReplyDeleteNo there are no studies on castor oil beyond using it for shine. Yes as stated in the article, there is some evidence in mouse studies that massage may help stimulate regrowth from an already existing follicle, so there may be some truth to that. As to whether castor oil also plays an additional role - nobody knows
DeleteI don't think anything can truly thicken a hair strand. There are products/treatments that give that illusion (ex: hair color) but, as you mentioned, they are temporary.
ReplyDeleteAwesome post...and this is why I love your blog! The research and information is always helpful!!
ReplyDelete~Shae of AfroniquelyYou.com
"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" -- how would you like that job?
ReplyDeleteThanks for the info, it's good to know it's more about the actual massage than it is the oil action if anything.
I had better luck using herbs like fo-ti and rosemary to thicken and grow in hair in thin spots on my scalp where I yanked it out taking out braids. I was so scared that the traction alopecia spots would be forever bald. But after some research I put together a concoction based on those herbs and others that seems to work for me. And castor oil ain't in the mix! lol
ReplyDeleteThank you for this informative article. I was misguided all this time!
ReplyDeleteAlso, I would like to know, does caster oil has anti-fungal property and help reduce dandruff?
The source which told told me that it helps the hair to thicken, told me about anti-dandruff property as well :(
I don't believe this article is correct, what so ever!!!
ReplyDeletelol I normally ignore comments like this. You are clearly new here. This is a scientific evidence based blog and you are completely free to disagree here (hence the disagree button above). However, in order for your view to matter, it would greatly help to simply elaborate on what you think is incorrect, not just make a blanket statement like 'that is wrong'.........what, why, how?
DeleteJc, I agree. It aggravates me when folks comment and fail to express in detail why there is a disagreement. I happen to appreciate any information I read. So thanks to all contributors. Our main goal is healthy hair. Right?
DeleteI prefer lighter oils so I'd not use a castor oil to find out if it increases thickness or encourages growth :-) I have bad memories of.being made to drink it when constipated lol
ReplyDeleteMs. Amena
Fb/Instagram:: Torrid Tresses by Ms. Amena
I don't believe castor oil itself increases growth but it may help in retention. I say that because it may help lock in moisture a little longer than lighter oils. Hair loves moisture. Dry hair breaks as does over moisturized hair. However, using too much castor oil can cause a problem as well in terms of product build up on strands and the scalp. If there is too much, moisture from the air will have a hard time getting through. From what I read in the past, castor oil is supposed to act as an humectant as well. With that said it can draw moisture in or draw it out depending on the environment. Understanding that, my theory is it doesn't accelerate growth but helps retain temporarily. I hope that makes sense. In addition, I've used it and haven't seen any accelerated growth. In terms of growth, I tell people to regard their strands as a delicate fiber. You don't wash your best items with terrible cleansing agents so you shouldn't do so with your hair. You don't purposely tug and misuse your delicate garments so don't do the same with your hair. Treat your body well, eat right, sweat via exercise, and love the inner and outer you. It will all come together in time.
ReplyDeleteI feel that each individual is different, therefore, different things works for different people. I swear by Castor Oil. I was bald on both sides of my head from pulling out micro-braids and I had used everything in the hair growth section for about five years. I heard about JB Castor oil and I started to use it, after about 8 weeks, I started seeing new growth and it has continued to grow, so don't comment if you have not tried it for yourself. studies and research are fine, but if you have not tried a thing, you really cant say what do or does not work.
ReplyDeleteYes I must agree with you. I too have seen incredible results with jbco. I think people should try it out for themselves to see how it may work for them. I am totally happy with the results I've gotten over the past 7weeks
DeleteI too agree with both comments - I have seen results of hair growth in the last 8 weeks on bald spots on both sides from years constant on/ off braids extensions. Now a full natural (4b/c) I use JBCO every night along with a light massage (not too heavy handed) Having tried other various concoctions of hair growth for this area JBCO is the one for me and will remain so for the time being.
Deletecastor oil is used widely in India..for a newly born child castor oil is massaged to his body and head.we believe that it protects his soft scalp in his tender age and also stimulates hair growth.For skin it gives moisture and smoothness.There is no age limit for its use.But if over used it may sometimes cause over heat in the body.But really as you see the people who use it daily for their skin and hair have no problem with the affect of pollution.Now i have a longer hair,a strong one,and a bright Indian skin.I swear castor oil did well for me!!
ReplyDeleteThats great to know Sammy. Would like to know how do you use it on your hair (daily / weekly, an hr/ full night etc) and on skin to have that brightness? Thanks in advance!
Deletei have used castor oil and it has healped tremendously .. yes i feel it works.
ReplyDeleteBridget, sorry all the previous comments and discussions on scientific analysis and anecdotal evidence are now deleted as the anonymous commenter has now taken to spamming this blog daily, naturally I am not entertaining this type of nonsense.
ReplyDelete