Ghrelin (human) is the endogenous agonist peptide for the ghrelin receptor (growth hormone secretagogue type 1A receptor or GHS-R). Ghrelin (human) is produced mainly by the stomach, and is linked to inducing appetite and feeding behaviour, with circulating ghrelin levels being highest before a meal and the lowest after. Injections of ghrelin (human) in both humans and rats have been shown to increase food intake in a dose-dependent manner and also to increase motivation to seek out food.