Years ago, I stumbled across a well-written story about a MALE investigative reporter following a sexploitation lead. Needing to go undercover at a private girl's academy, he tried a new injectable drug a researcher/friend gave him that transforms user into a teen girl. The catch - change can be reversed by a second chemical or (I think) wears off eventually; BUT if a double dose is given, the change becomes permanent. He took 1 dose, transformed, hid the vials in a trunk, was accepted at the school as a female student. Someone broke into trunk, took the vials and… voila, maybe the creepy son of school administrator gets a sex toy.
I rated it a "Keeper" in my notes. Sadly, a PC crash ate the link to many URL's I'd accumulated, so if you find it or if someone recognizes it, pls let me know! TIA