Can be a side effect yes but not a given. Also depends on the dosage and the person.

Some people like to be big in a t-shirt and not worry about the posing aspect. I rarely take my top off in public and I'm not that big. Im not ashamed or shy or owt but its just that I don't wish to be judged. Why can a fat fuck walk about with no-one batting an eyelid but a gym goer is branded a poser?