He'd worn a tank top, anticipating that he'd need some feminine clothing if the formula was a success, but neglected to realize just how...substantial his chest was about to become. Not just in the pectoral region, but all the way down his torso, in a series of quivering new growths...quivering due to his own ragged breaths and his struggle to stay upright through the change. It was taking him further in an animalistic direction than he'd expected, his thighs and feet were no longer designed to sustain him on two legs. Such a strong urge to drop to all fours...but he needed to be able to tilt the bottle back, to drink all of it, to ensure that ALL of him would change, and that it would be permanent...
He gave out a husky groan as he felt his gonads retreat up into his body with a schlorp, reshaping, reforming...his member still jutted out, but was shrinking smaller and smaller, becoming lost within his new folds...