What's the deal with metal and henna?

[Karala]

Sorry, I'm sure this has been asked before but I couldn't find anything through the search engine :/

I was reading about henna and I've just had a "DUH" moment realizing that for the last few months, I've been using one of these devices to mix my henna: (sorry, I don't know the name in english...)
....HELLO!! ok, so I've been using something with metal without even realizing I was doing it... yes, dumb.

My concern is that my henna tends to go way too dark for my taste, even though my natural color isn't very dark, even though I mix it with lots of cassia and chamomile and never let it sit for more than a couple of hours...

Could this be the culprit? I've known for ages that you're not supposed to use anything containing metal to mix henna, but I've never known why... is there any chance that it would actually hinder dye uptake, hence making hair darker but not much redder?

[ladyships]

maybe?

i mixed my last henna batch in a metal bowl—somehow had had no clue about the henna + metal thing—& it didn’t stain as bright on my virgin roots as any of my other hennaings had, & i couldn’t figure out what the hell was wrong for the longest time.

word of warning: i bought one of those copper hairbrushes a little over a month ago & i realised my [thrice hennaed] hair has gotten noticeably darker last saturday when a friend of mine who hadn’t seen me since the end of february commented on it at a party. really pisses me off, since i love the new hairbrush, but my hair’s already pretty dark & you can’t see the effect of the henna except in direct sunlight now. i only brush my hair twice a day, sometimes only once. yet my henna has gotten muted as all get-out. nuts, right?

[walterSCAN]

According to this article by Henna Sooq it shouldn't matter if you are using 100% pure henna...

I've never noticed a difference whether I mixed with a plastic spatula or a metal spoon...

[marisa]

I'm not sure about all that either.
The henna I've been using (Karishma brand) suggests letting the mix sit overnight in an "iron vessel" for darker color. I've used a cast iron skillet and it does seem to make my greys more auburn than orange.
I would love to use my handmixer but am nervous about the metal blades.
Been keeping an eye out while thrift store shopping for coated ones.

[girloctopus]

I've used both a metal immersible blender and aluminum foil to do henna streaks and highlights, and I've never noticed a difference. I've only heard of iron making a difference, since it is traditional in India to make the henna darker. But the metal that your mixer is made of is most likely stainless steel, which usually does not rust or tarnish, indicating that it is resistant to oxidation and unlikely to make your henna darker.

[ktani]

Metals are not recommeded to be used with herbs in general, except for stainless steel and there are variations with that (quality). They can interact with them if the herbs are acidic. Henna is about pH 4.5 when mixed with water. That said, it depends on the kind of contact. Brief contact should not have much of a result. Prolonged contact with a liquid mix or with heat may just affect certain results.

[caribou55313]

If those mixing blades are stainless steel, there won't be any interaction. I have used stainless steel bowls and utensils for mixing henna without a problem, including leaving them in contact with the paste overnight.

[halo_tightens]

If those mixing blades are stainless steel, there won't be any interaction. I have used stainless steel bowls and utensils for mixing henna without a problem, including leaving them in contact with the paste overnight.

I second this. I always use metal utensils to mix my henna, and I've never had any problems with it.

One difference, though, might be that I use only water or chamomile tea to mix my henna, so it's not overly acidic. There might be more potential for interaction, as ktani mentioned, if you use an extremely acidic liquid in your mix.

[alwayssmiling]

I have used Lush Caca with metal spoons, and clips - nothing bad has happened at all.

[Katze]

I am a henna artist and stir/mix my henna paste in a glass jar with a metal knife. Have been doing so for 14 years and see no problems with the paste's staining capacity...