Chica1 is curious… I’ve read on a henna forum that metallic salts from lower quality henna can react with your relaxer and cause instant damage (possibly melting) to your hair. If your hair was properly washed after using the lower-quality henna, why would the metallic salts react to the relaxer? I would assume that once your hair was washed, it would be neutralized. I understand that the metallic salt could potentially cause damage and once a relaxer was used, it could inflict further damage but I don’t understand the “melting” theory. Could someone clarify that for me? I was a political science major that probably should have taken more science classes!
The Right Brain responds:
Let’s start with a little background on henna and hair.
Henna chemistry
True henna (Lawsonia Inermis) comes in one, and only one, color: reddish-brown. Black henna, blonde henna, etc are actually “compound henna” and are made by mixing henna with either a oxidative dye like para-phenylenedmine (PPD) or a metallic dye like lead acetate.
What is “Melting” hair?
Hair doesn’t really melt. But it can take on a mushy, rubber band-like consistency when its protein structure is over damaged by exposure to alkaline conditions (from bleaching, relaxing, high lift tints, etc). Have you ever pulled hair out of your sink after using a drain cleaner? That’s what so called “melted” hair looks like.
Does black henna cause melting hair?
Black henna can be dangerous because it may contain PPD which can cause allergic reactions. But the presence of metallic salts per se don’t damage hair and these salts do not significantly interact with the sodium, lithium, or calcium hydroxides used in relaxers. It’s more likely that the culprit is multiple relaxer applications. This is even more likely to be the case if you’re relaxing your own hair because you have less precise control over the overlap.
The Beauty Brains bottom line
There are issues with using black henna, but melting hair is not one of them.
Reference: http://www.hennaforhair.com/science/
Do you want to learn more about how beauty products really work?
Download our FREE guide!
{ 8 comments… read them below or add one }
Black ‘henna’, or at least decent black henna, is made from the indigo plant, not from adding PPD (or anything else) to red henna. Indigo isn’t henna technically but it acts and is used in the same way.
Lush do an indigo ‘henna’ that contains no metallic salts or PPD.
Oh, wow! That was my question! Thanks for posting it here. I actually did a few strand tests and relaxed my hair -by a professional stylists – yesterday. Maybe too soon to tell if there was any damage but so far so good! I did strand test using BAQ henna and will definitely use again. Its appears to be a much safer way to color my greys and my current highlights are the same color as my strand-tested hair.
So do metallic dyes react badly with permanent hair dye or bleach? I’m confused now. I was always sure that was a bad combination.
One thing I read about metallic dyes–and it could be wrong–is that something about them coats the hair with repeated use so (as I recall) the coating doesn’t allow certain chemicals during (color) processing to escape. Which is different from a chemical reaction.
Well thanks for that heads up guys.. It sure does gave me information and knowledge about it. I can use this for my cosmetology ce study case.
One thing that may mitigate some of the damage during the relaxer is the pretreatment that is placed generously on the previously relaxed hair. I’m not sure if its a neutralizer or what it is but it is supposed to protect the previously relaxed hair from overprocessing. I’m not sure if a stylist can perfectly apply the relaxer without the overlap so that step is crucial.
While getting my relaxer, I noticed a number of women getting highlights and other color treatments. I didn’t notice any pre-treatment and most were still processing after my stylist directed me to the back for washing. Witnessing this really convinced me to learn more about henna. Thanks again for the follow-up!
That’s good to know, especially since I have relaxed hair and have contemplated using henna
Great info and advice as always!
http://bowtiedbeauty.blogspot.com/
@Sarah: In theory, anything that coats your hair can (to some degree) impede the dye chemicals from penetrating into the hair shaft. So yes, I suppose, if you had a lot of metallic dye on your hair you might have interference with oxidative dyes or bleaches. But in reality, the amount of metallic dye left on the hair probably won’t cause a problem. In any case, metallic dye would not stop chemicals from “escaping” from your hair during color processing.
Okay, so could lead acetate act as a catalyst in any way when hydrogen peroxide comes in contact with it? Sorry, I’ve just been told for so long that some kind of reaction occurs that I’m resistant to changing my idea…
{ 6 trackbacks }