Are Omega 3 fish-oil pills only used as dietary supplements?

I want to start taking fish-oil pills with Omega 3 in it, but I don't really care about the dietary reasons; I'm already skinny/ slender, and I don't want to get some eating disorder from taking diet pills (if it'll even affect me). I heard that fish-oil pills are a great beauty product and does wonders for your skin. Would it be "hazardous" to take these pills?