Sent to you by redcliff via Google Reader:
Sandra's henna hunch…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 replies:
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.
How Henna Works
This much is true: the active ingredient in henna is lawsone (also known as hennotannic acid or 2-hydroxy-1,4-naphthoquinone for the chemistry geeks in the audience.) It's a red-orange dye that reacts chemically with keratin protein via a process known as Michael addition. It leaves a strong, semi-permanent stain which makes it useful in creating mendhi, those decorative Indian skin designs. The brown stain sticks around for so long because it binds to your skin's protein. But we can find 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.
Things you can do from here:
- Subscribe to The Beauty Brains using Google Reader
- Get started using Google Reader to easily keep up with all your favorite sites
