Lightening hair after henna?

[cheeseismydownfall]

Since discovering I was a HoC autumn I changed my hair colour from highlighted blond to auburn and loved it. Initially I just used chemical dyes, but the red colour faded so quickly I thought I would try henna. Initially I loved it, when it was over the top of the highlights, but since the highlights have all grown out now the overall colour with henna alone is too dark and I don't think it is doing much for me.

Is there anything I can do to lighten it, or do I have to wait for it to grow out? My hair is reasonably short, so I'm tempted just to try a chemical dye (I know, I know) and cut it off if it goes wrong! Any advice?

I may be wrong but I think I was told that colouring with Henna is different to using the normal type of hair colour and that it is fixed in the hair shaft. Hopefully a MN hairdresser will be along with advice soon.

Yes, I have also read that and that you should never dye over the top!! But think I might try anyway unless someone comes along and stops me!

Ok, I know all about this subject! sonata is correct, henna penetrates the hairshaft making it more or less impossible to remove. It's not like chemical dye.
You CAN safely bleach (or use dyes containing peroxide) over henna IF the henna you used was pure henna powder with no indigo.
Peroxide over indigo results in streaky green hair.

But: all that will happen with bleach is that the hair will get lighter and lighter orange until the hair disintegrates (unless your hair is super strong, in which case you might be able to get it a light enough yellow to tone - but it will be very dry)
A peroxide containing dye to lighten it might be ok if you don't mind it still looking quite red.

Darker dye on top of henna might work, but very often the henna red shines through no matter what you put over it. Also henna tends to repel dye (so that even permanent dye washes out in a few washes)This doesn't always happen though, some people can put dark brown dye over henna fairly successfully.
If you can, do try strand tests before any dye.

The best thing to do is let it grow out. I know all this stuff because I had to grow henna out myself (I used henna when I was 14, and it's taken me over 3 years to grow out because I have long hair)
Hairdressers often know nothing about henna (only stuff they were told in hairdressing school all of which relates to compound henna, so they think it's all the same)

Ooooo thank you Isadora! I think I am going to try a peroxide-based dye to lighten it a shade or two. I like the red, that isn't the problem - it's just too dark. I haven't been my natural colour in about thirty years so I don't think I realised how dark my hair is when it isn't highlighted.

The henna I used was 100% pure henna powder, so definitely no indigo.

Will report back :)

Oh good. I think most people who want to get rid of henna (including me) have just got sick of having red hair. Mine is very blonde, so growing it out has been a real pain, I've had to use a semi permanent brown over it = (the washes out completely in 8 washes kind, with no peroxide) to disguise the color difference.
If you still like red or reddish hair, that should make it much easier!