what you say is use for medical reasons and not athletic purposes while the vet says that everything is ok, most of the uses for "training aid" included also thyroid hormones. Clen by itself helps you to loose way in similar ways with ephedrine. After the first time you use it the effect minimizes, personnal experience that is.
Another lighter option is aerolin (salbutamol).
high praised in the past, easily replaced by ephedrine in later years. For anabolic/anticatabolic effects if you are vto use drugs obviously there are much better options. Another bronchodilutor, natural remedy, is a mint tea.