In the spirit of Sir James Young Simpson, the search for the better general anesthetic continues today. An ideal anesthetic would cause unconsciousness quickly, would display no side effects, and would require no "maintenance" by an anesthesiologist .Unfortunately, such a perfect chemical does not yet exist. There have been many improvements since the days of ethyl ether and chloroform usage. Today, many anesthetics are given intravenously so that they are absorbed more quickly and the effects on the body occur rapidly. Two new inhalation anesthetics introduced in the 1990s that are used frequently are desflurane and sevoflurane.

Through the 1930s and 1940s, cyclopropane, trichloroethylene, and ethylene were among the general anesthetics used. In 1951, halothane, also known as fluothane, was synthesized. Five years later, it was introduced into the realm of medicine for use as an anesthetic. A nonflammable, volatile liquid, halothane is a potent anesthetic, and unfortunately, has a much higher price tag than chloroform and ethyl ether. Halothane has no nauseating odor, such as ether, but has been shown to affect the cardiovascular and reproductive systems in humans. Though halothane is still in usage, the common choice of inhalation anesthetics of today include nitrous oxide, desflurane, isoflurane, and sevoflurane.