I was a little skeptic about this product when I bought is as it was a low price and had some bad reviews. However I have been blown away by this product! This is a long review but has all the info you culd probs need so! :) (Background hair: mid brown with bleach highlights all over with very coppery (ginger) tones and highlights; from previous browny red/purple hair dyes that end up fading) being in the sunlight my hair tends to go lighter, ginger-er. The highlights were a honey blonde colour with some being paler and other more coppery. Also note that i have long hair (just above waste length) and quitle a lot. One packet was more than enough for one application, with some left over for extra coverings. I used this as i would a conditioner (with little more sectioning and care applying) in my shower, left on for about 10 minutes. Firstly, the smell is gorgeous! The consistency is quite mud like, clay-ish, a bit weird but easy with applying to hair. When i rinsed, i found my hair felt lovely and smooth which i wasn't really expecting! I did apply my usual conditioner afterwards just incase it did dry it out though. (also to help with getting all the blue out of hair, as on some of my highlights there was a noticeable blue tinge, but came out with this second rinse!) When it was dry, it still felt soft! I was more impressed with the results of the colour; my brown was a less orange - more mousy/ashy. My highlights are paler and it has all mixed in well to a less orange brown+highlight! It isn't chnaged dramatically, but enough to notice! Considering its a little (fairly cheap) packet, I wasn't expecting uch great results! I can imagine using the shampoo & conditioner and the mask will give dramatic differences! I would definately recommend if you have mid brown & lighter hair, even bleached! I wouldn't have thought it would work so well on dark dark hair, but I can't say unfortunately. Also if you have bleached hair and it's gone orange, maybe this isn't going to work on its own, but if its more blonde with hints of orange then this should be able help! This range's shampoo & conditioner is next on my shopping list!! :) Thanks, I hope this helps!

Did not make any difference at all to my mid-brown hair (originally ash brown, now with brassy bits). Left it for 10 minutes. I guess it is better for lighter or highlighted hair.

Absolutely LOVE this product!! I have balayage hair with very light ends and this saves my hair in between hair appointments. As my hair is dark at the top it can tend to go brassy/orange as it starts to fade into the blonde which I hate! I used this once with the shampoo and conditioner and there is a noticeable difference! So, so pleased!! Please sell the full size product!

I never thought putting Blue goo in my hair could change my life. I’ve always struggled to get a clean blonde look but this ABSOLUTELY nails the brass. Amazing!

This product is brilliant in between hair appointments, it's refreshes my blonde highlights to perfection. I'm naturally quite a dark brunette so I tend to go VERY brassy so I absolutely love this. Definitely recommend to anyone with who goes too warm.