Sermorelin vs. Ipamorelin: Which Peptide Is Right for You? Sermorelin and ipamorelin are two of the most popular growth hormone releasing peptides used in peptide therapy to stimulate natural production of human growth hormone (HGH). While both work by mimicking the body’s own growth hormone-releasing hormone (GHRH), they differ in potency, receptor selectivity, side-effect profile, and practical considerations such as dosing frequency and cost. Understanding these differences helps patients, clinicians, and researchers choose the peptide that best fits their goals—whether it is to enhance muscle mass, improve recovery, reduce body fat, or address age-related decline in HGH levels. Introduction to Peptide Therapy Peptide therapy refers to the use of short chains of amino acids (peptides) administered by injection or other routes to modulate physiological processes. Unlike hormones that act systemically, peptides typically have high specificity for their target receptors and a relatively rapid onset of action followed by quick clearance from circulation. This pharmacokinetic profile allows precise titration and reduces the risk of prolonged overstimulation. In the context of growth hormone therapy, peptide agents such as sermorelin, ipamorelin, and others are used to stimulate the pituitary gland’s natural release of HGH without directly administering exogenous growth hormone itself. The advantage is a lower likelihood of adverse effects such as water retention, joint pain, or acromegaly that can accompany high doses of recombinant HGH. Sermorelin vs Ipamorelin: Choosing the Best Peptide for Growth Hormone Mechanism of Action - Sermorelin is a 28-amino-acid synthetic analogue of growth hormone-releasing hormone (GHRH). It binds to GHRH receptors on pituitary somatotrophs, triggering the release of endogenous HGH and insulin-like growth factor-1 (IGF-1).