A category of drugs that can be legally prescribed but are the most stringently monitored because of their potential for abuse and {diversion.
Schedule II drugs include stimulants such as cocaine, amphetamine and opiates such as fentanyl, which is far more dangerous than heroin, even though the latter is Schedule I. While Schedule I drugs have been deemed as having "no medical value" and cannot be prescribed because they are presumably the most dangerous, Schedule II drugs are generally far more dangerous and addictive than Schedule I drugs. The fact that
non-lethal drugs such a cannabis, and psychedelics such as LSD and
peyote are Schedule I drugs
say more about the period when the schedules were created (as part of the 1970 Controlled Substances Act, under Nixon) than they do about the actual danger of the drugs.