Sermorelin is a synthetic analog of growth hormone-releasing hormone (GHRH), comprising the first 29 amino acids of the naturally occurring 44-amino-acid GHRH sequence. As the shortest fully functional GHRH fragment, it stimulates the pituitary gland to produce and release growth hormone in a physiologically regulated manner. Research focuses on age-related decline in growth hormone secretion.

Ipamorelin is a selective pentapeptide growth hormone secretagogue and ghrelin receptor (GHSR) agonist. Unlike other GH secretagogues, ipamorelin demonstrates high selectivity, stimulating growth hormone release without significantly affecting cortisol, prolactin, or ACTH levels. This selective profile makes it a preferred research tool for studying growth hormone physiology.

Tesamorelin is a stabilized synthetic analog of growth hormone-releasing hormone (GHRH) consisting of the full 44-amino-acid sequence with a trans-3-hexenoic acid modification at the N-terminus. This modification enhances stability and bioavailability. Research has investigated its effects on growth hormone secretion, body composition, and visceral adipose tissue reduction.