You're an 18-year-old male student who's just moved to a college town and settled into a dorm, and naturally now you're away from home you've started to take the opportunity to experiment with stuff. You're getting into some new music and TV that your dormmates like, got some new clothes and are beginning to become curious about your gender and sexuality. So naturally, trying out being female struck you as a lot of fun.
Just before taking the tablet, you lock your dorm room door, stand in front of a mirror on your closet and strip naked, wanting to see your body when it changes. You swallow the tablet with water, and after a few seconds you feel weird in a really pleasant way as it starts to transform the hormones all through you from masculine to feminine. A sort of fizz extends down your throat like drinking something carbonated, but instead of dissipating it seems to spread through you, making you feel warm and tingly all over.
And sure enough, soon your body starts to gradually change. It seems to slightly shrink in lots of places, as you lose a few inches of height, your hands and feet turn more petite, your muscles turn more lithe and your figure turns from firm to curvy, with your shoulders shifting inwards while your hips grow wider. You notice your head and face change dramatically until you have a narrower neck without the bulge of your larynx visible anymore, a softer jawline, puffier lips, softer cheeks and practically hairless skin. In fact, all over your skin seems smooth and supple now.
Just as you're thinking how you used to look very distinctly like a boy and now you look very distinctly like a girl, an unfamiliar arousal wells up in you as the changes reach the most intimate areas of your body. Your nipples expand as mammaries form in your chest, and you're transfixed by the sensations you feel from them- it's like some kind of latent part of you has emerged, and you want to satisfy it so bad. Before your eyes, as you breathe heavily you see soft mounds swell under them and realise you have breasts now. Once they've formed into C-cups, you feel something odd between your legs and look down to see your penis contracting. It only seems to turn more sensitive as it turns from a large phallus to a tiny sensitive nub. Your testicles move up into your body and reshape into ovaries, and your scrotum tucks inward until it splits down the middle into labial lips, forming the opening of your new vagina.
As the weird sensations subside, you stare at yourself for a moment. It's weird- you look like you used to but just, well, a young woman instead of a young man. You do kinda like how you look, or at least how your body looks, so it's a success on that front. You wonder what to do now you've changed...