Analogs of CRF, which are based upon rCRF, oCRF, sauvagine and alpha-helical CRF, are disclosed that can be administered to achieve a substantial elevation of ACTH, beta -endorphin, beta -lipotropin, other products of the pro-opiomelanocortin gene and corticosterone levels and/or an increase in blood pressure over an extended period of time. One analog which has been found to be particularly potent is: H-D-Pro-Pro-Ile-Ser-Leu-Asp-Leu-Thr-D-Phe-His-Leu-Leu-Arg-Glu-Val-Leu- Glu-Nle-Ala-Arg-Ala-Glu-Gln-Leu-Ala-Gln-Gln-Ala-His-Ser-Asn-Arg-Lys-CM L-Nle-Glu-Ile-Ile-NH2. In the analogs of the native 41-residue polypeptides, one or more of the first six N-terminal residues may be deleted and/or the N-terminal alpha-amino group may be acylated by an acylating agent containing up to 7 carbon atoms. A number of other substitutions may also be made throughout the chain. These analogs or pharmaceutically or veterinarily acceptable salts thereof, dispersed in a pharmaceutically or veterinarily acceptable liquid or solid carrier, can be administered to mammals, including humans. These analogs may also be used as stimulants to elevate mood and improve memory and learning, as well as diagnostically.