The Controlled Substances Act is the federal drug policy that regulates the manufacture and distribution of controlled substances such as hallucinogens, narcotics, depressants, and stimulants. The Act categorizes drugs into five “Schedules” or classifications based on their potential for abuse, status in international treaties, and any medical benefits they may provide.
Hormones are carried by the blood stream to their target cell once there they bind to the cell. the answer to your question is they are carried by the bloodstream.
Vaccines protect the entire community by preventing outbreaks and making it harder for diseases to spread.
