Step-by-step explanation:
Off-label use is considering the use of prescripted pharmaceutical drugs or over-the-counter drugs. Examples are pharmaceutical drugs called Prazosin, Memantine, Clonidine, Naltrexone, Clomiphene, and more.
Extra-label use is considering the use of approved drugs. Examples are Chloramphenicol, Diethylstilbestrol, Ipronidazole, Clenbuterol, and more.