Medizin is also the science of health and medication. To become a doctor you must first "study medicine" (i.e. by going to university for many years, not just look intently at a bottle of cough syrup).
Medizin might also specifically refer to a liquid medication, rather than pills for example, according to Duden.
sir I have just called the ADF please state your location so i can dispatch a joint US and German raid if possible