Dustin looked at himself in the mirror, noticing the changes just a very small sip of the potion had done. He took his shoes off to let his slightly larger feet breath, and saw how his pants were a size too short, and a bit tight. His hair was longer, and he liked how he looked. If these were just the first small changes, he couldn't wait to see what else the potion had in store for him!
Before taking it all down, he decides to give it another drink. A bigger one this time. It tastes a little bit better, and he leaves about three quarters of the potion left. Somehow it feels like he's reached the limit of what he should drink safely. He doesn't know exactly how much he will change if he drank all of it, after all.
This time, it takes more time for him to see the changes, but after a few minutes, he sees them begin. Looking down, he can actually see his feet becoming longer, veins and tendons bulging as they also became thicker. If he ad been wearing his sneakers, these new feet might have torn through them like the Hulk! Just like his feet, his hands have grown quite a bit, with thicker fingers and a bigger palm.
His excitement is beginning to show in his dick, which is hardening at the changes. It begins to hurt as he grows taller, and his legs grow thicker. His jeans reach almost halfway down his calf, and he has to unbutton them so it doesn't fly off. His dick had grown a lot too, and he takes it out of his tight undies with his big hand. It is hard as hell. His t-shirt is much tighter than it was before, his sleeves all the way up to a pair of shoulders that are much bigger. His hair is now almost down to his shoulders, thick and manly. Looking down at himself, he calculates he's about 6'2'' and about 210 lbs of muscle. His clothes were made for a kid, and he was now a very big man.
He begins to feel more like a man when he notices a stubble grow on his formerly hairless face. Hair begins to grow thick and manly all over his body...his legs, his arms, even his chest.
Dustin begins to feel strange. He was very satisfied with the changes but something tells him they're not done with him yet. Suddenly he feels dizzy, and decides to rest a little. He takes off his clothes to expose his huge, hairy body, and the dimenisons just feel totally new to him. He has to get used to being big now, and it makes him even more dizzy. Dustin opens a drawer and takes the biggest pair of pajama pants and an oversized hockey jersey he once wore as a costume, and falls on his bed.