Covering grey

[40thisisit]

Can you recommend a home hair dye that is great at covering grey? As the ones I've been using only seem to cover them for about 2 weeks :(

I use whatever happens to be on special offer but always leave it on for 15 minutes longer than recommended, it last about 5 weeks. I will have to lighter eventually but I do like my dark brown hair.

I sadly got my first grey hair at 13 . I'm 25 now and a couple of years ago my hair dresser told me I was 55% grey.. I don't even want to know what percentage I am now.

I have always dyed my hair myself and used every box dye out there. I have found garner nutrisse to be the best for grey coverage.. although John Fredia comes a close second and I always opt for JF because it being a mouse it is so much easier to do yourself and if you have long hair the product goes a lot further.

Thanks for the advice, I'm going shopping tomorrow!