I have dark spots all over back and chest.

Hi: Dark spots can be anything! They can be moles, skin tags, dark freckles, and so on and so on. The only thing I would want you to do is go to your doctors and ask to see a dermatologist! They need to be looked at before you do anything. Sometimes it's even a reaction to heat or the sun. It can be genetic! The list is extensive, and a dermatologist can tell you immediately what they are! Once you get in to someone can you let me know how things go and what they said? Good luck and health!