Tuesday, 14 April 2009

Inquiring minds: Henna - How does it work? Part 1 of 3

On Friday (I think), I received an email from one of my readers and she asked some very interesting questions which had my scientific spidey senses tingling.

She says - "I've recently discovered the plethora of natural haircare sites on the internet, and yours has been one of the more fascinating (Thankyou :)). I have a question that I hope you can help me answer. On a lot of the sites I've perused, I've seen various claims made about henna; the most prevalent is that henna

1. Is a deep conditioning agent and hair dye
2. Helps condition and define and sometimes loosen curls
3. Binds to the hair and makes it stronger.

However, most of the before and after photos I've seen of folks who've done it simply look like they've had some sort of texturizer, which as far as I know, weakens the hair.
What is true? Does henna weaken hair or does it really deep condition for the better?"
There were so many questions to answer so I decided to break this up into 3 parts - I hope you read all of them!!

How does Henna work?
Henna contains a chemical known as Lawsone which DOES dye hair. It is a coating dye. It is thought that the dye is highly attracted to keratin, the type of protein that makes skin, hair and nails. It is NOT thought to be a penetrative dye and operates by attaching itself to the hair cuticle (outside of the hair). (International Journal of Cosmetic Science, pg153-174, 1982 and Journal of the Society of Cosmetic Chemists pg 359-267, 1986)

Does Henna condition hair?
Traditionally, a conditioner should ideally add moisture or softness to the hair. Henna does not do this. In fact, hairdressers report that henna can lead to dry hair (Book Reference – The Art of Hair Colouring by Jacki Wadeson, pg 19). Some liken the effect of hair to a protein treatment. However, Lawsone in Henna is not a protein and its action is different.

Click here for part 2 - Henna - Myths and Facts
Click here for part 3 - Henna - A serious note

Image Credit


  1. hm... this is really interesting! i wondered why i had to deep condition my hair after applying cassia...

  2. I'm not sure on cassia. I'll do a post for you on it :)

  3. Thank you for this! I've been traveling for a few days, so I didn't realize that you had answered my question. Now, I'm catching up, and your information is fascinating. Once again, thank you!

  4. Thanks for the questions!! It sparked some really good discussions, make sure you read the post (and comments are a must see!) afterwards on curl loosening!

  5. you're suppose to add 1 egg and olive oil to prevent dry hair.

  6. does henna block moisture from penetrating hair shaft?

  7. Thanks for this great website. I've switched to Henna a year ago. Henna dries the hair in the beginning, but after a few washes it smooths the hair and make it more softer than before the henna, why? I don't know but this what happens every time.
    You may want to take a look into this detailed article:


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