Hexarelin stimulates GH secretion. Hexarelin is more resistant to proteolytic degradation than GHRP-6. Hexarelin has 7 amino acids H-His-D-2-Methyl-Trp-Ala-Trp-D-Phe-Lys-NH2 and having a molecular weight of 887 Dalton. The Molecular Formula is C47H58N12O6.

Growth Hormone Releasing Peptides (GHRP-2, GHRP-6 and Hexarelin) are a small family of peptides acting at the pituitary and the hypothalamus to release Growth hormone (GH). These peptides were discovered 20 years ago and in clinical researches proved to be able to stimulate pituitary to produce endogenous Growth hormone. GHRP-2, GHRP-6 and Hexarelin are replaceable drugs and have similar mechanism of action.

Hexarelin is considered to be the strongest peptide stimulating GH secretion. With its use, the increase in cortisol and prolactin levels is also high enough. GHRP-2 is less strong than Hexarelin, but the increase in cortisol and prolactin levels is less too. GHRP-6 is less strong than GHRP-2, but when used in dosage up to 100mcg, it has no influence on the levels of cortisol and prolactin, and in dosage more than 100mcg, the increase in cortisol and prolactin levels is modest.

Another drug stimulating endogenous GH secretion is long-acting CJC-1295 (Long-acting Growth Hormone Releasing Hormone Analog).