they used to use mercury in hair dyes 7-10 years ago. the dyes still have bromide and choride molecules. I recently looked this up. I only dyed my hair for about 5 years but never felt well with the dyeing process. Hated it. so I went to a henna, and indigo process and immediatley felt better. You probably have a lot of heavy metals in your scalp. Its funny how hairdressers tell you that you dont absorb the dyes because it doesnt touch the scalp.