A method of improving health in an animal includes administering to the animal a nutritional supplement comprising an amino acid secretagogue composition, which stimulates the pituitary gland in the animal to produce growth hormone. The nutritional supplement may be administered orally. The nutritional supplement may comprise L-arginine hydrochloride, L-pyroglutamic acid, L-lysine hydrochloride, and cysteine. When desired, the nutritional supplement may consist essentially of L-arginine hydrochloride, L-pyroglutamic acid, L-lysine hydrochloride, N-acetyl-L-cysteine, L-glutamine, and schizonepeta powder.