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How long should you keep the bleach on your hair?

Whether you’ve bleached your hair or not, I bet you’re curious to what bleach does to natural hair if it’s left on for too long. In this post, this is exactly what our goal was: to find out in first hand what happens when you over-bleach your hair.

Getting the natural hair

After a little discussion we decided to actually do a bigger strand test on the hair. This means that you take a small section of the hair, place it on tape to keep it put, and apply the dye mixture onto it to see what tone you can achieve.

I decided to sacrifice a few locks of my own hair for it, a small bundle of light brown hair. They do have a bit of a natural wave on them, which made me curse that I didn’t think of straightening them beforehand.

What bleach to use

We used two different bleaches: one made with white henna and the other one being a typical boxed bleach that you can buy from the shops. We took a good 12 inch strip of tape, laid the hair out onto it and sectioned the foil underneath the tape. It was divided into several sections, first two being BLEACH #1 and BLEACH #2. BLEACH #1 is the average boxed bleach, BLEACH #2 is the white henna bleach.

Underneath that you can also see that both of those sections were divided into 3 stages: 15 minutes, 45 minutes and 1.5 hours. This is to show how long was the bleach kept on the section of hair. Let’s begin!

Mixing the solutions

Mixing the average bleach was nothing new: squeezed the tube and bottle into a bowl, mixed them together and the result was like a cake icing. It didn’t smell like ammonia like it should, and it was very easy to handle.

White henna box had a powder bleach and a pre-oxide in it, plus a conditioner.

Stage 1 – 15 minutes

After 15 minutes, absolutely nothing happened. The dye didn’t seem to have ANY effect to the hair what-so-ever.


( Click on the image to zoom )

The Henna bleach on the other hand seemed to have lifted the tone of the hair at least by one shade.


Stage 2 – 45 minutes

Boxed bleach shows very little change in the shades, it does look lighter but not by much.

White henna on the other hand has been working, as I wiped the hair clean of the dye it had actually bleached the hair and by a lot. The hair looked sandy blonde, if not strawberry blonde. Keep in mind we started out with light brown shade..



1 hour 10 minutes

The bleach has been working now for 1 hour and 10 minutes, I have not taken off the bleach yet but WOW, the henna is BUBBLING. It caught my attention because it actually makes a sizzling sound.

Stage 3 – 1 hour 30 minutes

Here’s the end result! The boxed bleach least said let me down. I really did expect more of it as it’s much more widely used than henna bleach.


The henna bleach on the other hand really took me by surprise. This is the bleach that I had set low expectations on, but it lifted the tone so much. The hair feels extremely dry and damaged from the bleaching.


Overall opinion

While bleaching in general is the worst thing you can do to your hair, it all comes down to personal choices in the end. If you want to bleach your hair, then prepare them for it: coconut oil hair masks, reading about how to bleach hair the right way and so on.

I decided to also include a better picture of what the bleach actually did to my hair, in contrast of a navy blue towel.


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