How can henna condition hair?

Sandra’s Got A Hunch About Henna:

Hi! I read your blog a lot, and it’s so interesting that I’m actually considering changing my major from Biology to Chemistry!

Anyways. I want to grow out my hair to very long lengths, so I’m always looking for ways to take care of it. A lot of people at the Long Hair Community use henna and swear that it strengthens and conditions their hair.

If I got it right from what I’ve read, henna coats the hair shaft, and even penetrates the hair to a certain extent, and binds to the protein of the hair, thus the strengthening. The coating effect smooths down the cuticle, so there you have the conditioning. So what`s the truth – Does henna condition hair?

The Right Brain Coos About Chemistry:

Sandra, we’re THRILLED to think our blog has helped you in in selecting your major. You’ll have to write back and let us know if decide on a career in chemistry.

Speaking of careers, The Beauty Brains have been in the hair industry for many years and we have NEVER seen a single technical reference that ascribes hair strengthening or conditioning properties to henna. While we`re big fans of the Long Hair Community (we`ve quoted them on several occasions) this one sounds like the kind of thing someone just made up or heard from someone else.

This much is true: the active ingredient in henna (called Lawsone) does have an affinity for keratin protein (like your skin and hair.) That`s why henna is used to create mendhi, those decorative Indian skin designs. The brown stain sticks around for so long because it binds to your skin’s protein. But there`s no evidence that this interaction has any affect on the structure of your hair. Modern hair researchers have the ability to measure how well ingredients penetrate into hair AND how they impact hair`s tensile strength. Good conditioners need to be able to lubricate the hair shaft to smooth the cuticle and there`s no data to show that henna is efficacious in this regard.

(Oh, and just in case you’re wondering, henna does do a good job of staining skin brown but it doesn’t really work well enough to help you quit getting grey hair.)