The neuropharmacological profile for thyrotropin releasing hormone (TRH) has been compared with various other types of central nervous system stimulants, and the results of the comparison, considered together with the results obtained by other workers, suggest that TRH may function as an endogenous ergotropic substance. Its ergotropic properties suggest that TRH analogues with better biological stability than the parent compound may be useful agents for treating some psychiatric disorders; for hastening the recovery of consciousness and respiration after anaesthesia; for treating narcotic overdosage or dependence, narcolepsy, minimal brain damage, and various neuromuscular disorders; and for aiding the diagnosis of "brain death".