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.
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.
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.
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.
There are issues with using black henna, but melting hair is not one of them.