Vitamin C on (old) Henna?

[Pearl07]

Hi guys, I'm new and i have a few questions on using Vitamin C to lighten Henna and I hope you can help me.
I've seen quite a few videos on YT of people lightening their henna drastically using Vitamin C, but its always been on pretty much freshly dyed henna.

I want to lighten mine bc although i like the color itself, it just doesn't suit me that much. But the thing is, I've dyed my hair with Henna about 3-4 times (not sure anymore) and last time was in May of last YEAR. My natural hair color is a very light brown btw.

Would using Vitamin C still make any difference? Has anyone of you tried lightening their henna with this method?

Also, i'd like to know if i can still go into the sun immediately after using vitamin C. Or is there, like with lemon, the danger of the hair turning white and snapping after doing so?

Plus, how gentle is this method? I don't really wanna damage my hair too much. I've heard different things, some people even said its good for the hair, which i doubt, but still not sure.

My last question, is there any other things that are a must know? Like, does vitamin c react to certain ingredients in hair products negatively? Or to chemicals like chlorine?

I'd much appreciate answers from you guys!

[Nightshade]

There's a reason it's on freshly dyed henna--Vit C is most effective before henna oxidizes.

The way henna binds to hair is via Michael Addition, which is an insanely stable chemical bond. This is why removing henna is so tough.

This bonding starts during application and finishes by the end of the oxidization process. So before and during the completion of the oxidization phase, you can get ahead of things a bit and the Vit C will remove henna that is not yet chemically bonded to the hair.

There were several tests by a former member who was desperately trying to remove her henna this way and hit on the fact that lemon juice / Vit C really only worked before oxidization. After that point, immediately after rinsing out the Vit C the henna would APPEAR as if it had been removed (lighter orange) but really all it did was somewhat shrink the dye molecules, and a few days later they just returned to normal with no substantial loss of overall color.

Generally Vit C is very safe, but it works much much better on direct dyes like indigo and Manic Panic than henna. Color Oops / Color B4 is generally better (though still not perfect) at henna removal.

Sun-In also does not remove henna, it lightens the hair UNDER the henna making it appear lighter overall. I wrote a big article about my use of Sun In + Henna here:
https://www.nightblooming.com/2020/0...oo-dark-henna/

Vit C is generally gentle, but it can be very drying and overuse will lead to lightening the hair over time (similar to how lemon juice cand), and damage.

Vit C generally doesn't react negatively to other ingredients or things on hair, but when in doubt, strand test!