How old are you? I dont see thinning. Fact is no hairline is prince charming perfect. It's hard to tell from the pic. To be honest your dad might be bald like mine (he started balding rapidly at the age of 21 according to him and my mom) but that doesnt mean you will be. My older brother lost most of his hair in his early 20s like my dad. I was receding in my mid 20s and my younger brother still hasn't loss any and he is 25. We need before and after pics to be sure of anything unless its obvious. In your case from the pic it isnt. Finasteride does cause shedding even for non balding men as its a hormonal shock to the body.