Are self tanning lotions harmful? Do they have dangerous chemicals in them? Is it safe to use?

Very safe. Self tanning lotions are very safe. They are simply staining the top-most layers of skin a brown color. I recommend my patients use self-tanners over using tanning beds or external tanning to get color. If your skin is getting darker from sun exposure, it is a pathogenic response to sun, and means your skin cells are trying to protect their dna by producing melanin. This is never good.