Ipamorelin

Ipamorelin is a synthetic pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) studied as a selective agonist of the ghrelin receptor (GHS-R1a) on pituitary somatotroph cells. Activation of this receptor is thought to stimulate pulsatile release of endogenous growth hormone (GH). Unlike earlier growth hormone-releasing peptides (e.g., GHRP-6, GHRP-2), preclinical work found ipamorelin did not meaningfully raise ACTH, cortisol, or prolactin at GH-stimulating doses, which is why it is described in the literature as a more 'selective' secretagogue.

Evidence is largely preclinical and early-phase. The foundational characterization (Raun et al., 1998) described ipamorelin's GH-releasing potency and receptor selectivity in vitro and in vivo (animal and pituitary cell models). A later randomized, placebo-controlled human trial (Beck et al., 2014) tested intravenous ipamorelin in surgical patients for a different purpose — accelerating gastrointestinal recovery after bowel resection (postoperative ileus) — and did not find a statistically significant benefit over placebo on the primary endpoint. There is no large-scale human evidence supporting use for body composition, anti-aging, recovery, or athletic performance in healthy adults; such uses remain unstudied in controlled human trials.

Educational overview only — no dosing instructions in the public hub.

As a GH-axis secretagogue, theoretical and reported effects in studied contexts include fluid retention, headache, injection-site reactions, and changes in insulin sensitivity or glucose handling. Long-term safety in healthy, non-patient populations has not been established in controlled trials. Because it is not an approved pharmaceutical, product quality, sterility, and labeling accuracy are not independently regulated in the research-chemical market.

Purity and identity should be verified by an independent third-party laboratory using a method that includes identity confirmation, purity/quantification (e.g., HPLC), and mass spectrometry (MS) — not solely a manufacturer's internal certificate.

Not approved by the FDA, EMA, or MHRA as a drug for human use. In the United States it has been the subject of FDA bulk drug substance nominations under Section 503A with restrictive determinations; it is commonly sold and referenced as a research chemical/RUO (research use only) product rather than a medicine. Regulatory status varies by jurisdiction and can change.