When the supply of energetic substrates is insufficient to slow the development of the catabolism, the next step is to focus on the neuro-endocrine mechanism which regulates the anabolism-catabolism balance. In this work, we review the endocrine response to stress and its implications in protein metabolism, in order to evaluate the different therapeutic possibilities available. Pharmacological blocking of the secretion of catabolic hormones (glucagon and catecholamines) has been unsuccessful up to now. Insulin is the only hormone which produces anabolism in all energetic substrates, but the results published about its administration with glucose and amino acids and its effects upon the nitrogen balance are controversial. The administration of anabolic steroids such as nandrolone, stanolone, and methenolone are usually associated with protein anabolism with minimum androgenizing action. The most recent works lead to the study of the effects of the use of GH and IGF-1 with clearly hopeful results. We have not yet acquired enough experience to use these methods in the habitual clinical practice. At the moment, the clinical studies are in the experimental stage and their application in nutrition is not accepted by the official authorities.