Tesamorelin + Ipamorelin Peptide Stack

This peptide stack features a strategic combination of Tesamorelin and Ipamorelin, both classified as growth hormone secretagogues. Tesamorelin functions as a GHRH analog, while Ipamorelin acts as a ghrelin receptor agonist. By engaging two distinct receptor pathways, this stack is designed to maximize the stimulation of endogenous growth hormone release. Research indicates that utilizing multiple mechanisms can enhance the overall anabolic response, offering potential advantages in clinical and preclinical settings. The dual action of these peptides may facilitate improved outcomes in studies related to body composition, metabolic health, and recovery, although further exploration is necessary to fully understand the implications of this synergy.

Tesamorelin (tesamorelin acetate) is a synthetic analog of human growth hormone-releasing hormone (GHRH) and holds the distinction of being the only FDA-approved medication for the reduction of excess abdominal fat in HIV-infected adults with lipodystrophy, marketed as Egrifta. This peptide has been shown to stimulate endogenous growth hormone (GH) and insulin-like growth factor 1 (IGF-1) production, leading to significant reductions in visceral fat. In the context of the SELECT trial, which administered 2.4 mg weekly by subcutaneous injection, participants experienced notable visceral fat loss over 26 weeks, demonstrating a generally favorable safety profile. The recent approval of Egrifta WR in March 2025, a new weekly-reconstitution formulation, marks a significant advancement in its therapeutic application. Mechanistically, Tesamorelin binds to GRF receptors on the anterior pituitary, promoting GH release and subsequent increases in IGF-1 and IGFBP-3 levels, thereby enhancing lipolysis and reducing visceral adipose tissue.

Ipamorelin is recognized as one of the most selective growth hormone secretagogues available, characterized by its synthetic pentapeptide structure (MW ~711.86 g/mol, formula C38H49N9O5). It is noted for its ability to stimulate pulsatile growth hormone release from the pituitary gland while maintaining a low impact on cortisol, prolactin, and appetite. This selectivity positions Ipamorelin as a favorable option in contexts such as anti-aging and body composition enhancement. Despite its growing popularity, research on Ipamorelin remains limited, and it has yet to receive FDA approval for any specific indication. The mechanism of action involves selective binding to the Growth Hormone Secretagogue Receptor (GHS-R1a), leading to increased cAMP levels and activation of protein kinase A, which ultimately promotes GH secretion. Notably, Ipamorelin does not appear to induce receptor desensitization, suggesting that its effectiveness may be sustained over extended periods, potentially allowing for prolonged research applications.