Ipamorelin

Updated June 29, 2026

Ipamorelin is a synthetic pentapeptide (five amino acids) and a selective growth hormone secretagogue — it stimulates the pituitary gland to release growth hormone without significantly affecting cortisol, prolactin, ACTH, or other hormones that most GH-releasing compounds raise as side effects. This selectivity is its primary clinical advantage over older secretagogues like GHRP-6, which reliably increases appetite and cortisol alongside GH. Ipamorelin works by binding to the ghrelin receptor (GHS-R1a) in the pituitary and hypothalamus, mimicking the action of the hunger hormone ghrelin to trigger pulsatile GH release.

The GH pulses ipamorelin produces are physiological in character — they resemble the natural peaks that occur during deep sleep and intense exercise rather than the supraphysiological sustained elevations produced by synthetic GH injections. This pulsatile pattern is important because it preserves the negative feedback loop: the pituitary still responds to rising IGF-1 and GH levels by reducing further secretion, maintaining the regulatory architecture of the axis. In contrast, exogenous GH suppresses the pituitary's own production over time. Ipamorelin stimulates without suppressing.

Benefits associated with GH secretagogues in clinical research include improved body composition (increased lean mass, reduced fat mass), enhanced recovery from exercise and injury, improved sleep quality and depth, stronger connective tissue, and better skin quality over months of consistent use. IGF-1 levels rise proportionally to GH output, contributing to protein synthesis and tissue repair. The time frame for body composition changes is 3 to 6 months — these are not rapid results but are sustainable and do not require post-cycle recovery protocols in the way anabolic steroids do.

Ipamorelin is administered by subcutaneous injection, as peptides are degraded in the gastrointestinal tract and not reliably absorbed orally. Standard dosing protocols use 200 to 300 mcg injected one to three times daily, typically first thing in the morning on an empty stomach and/or before sleep — timing to align with or amplify the natural GH release patterns. Combining ipamorelin with a GHRH analogue like CJC-1295 is common practice, as the two have synergistic effects: ipamorelin amplifies the magnitude of each GH pulse while CJC-1295 extends the release window.

Ipamorelin is well tolerated in clinical literature. The most common side effects are mild water retention in the first few weeks and occasional headaches from the GH pulse. It does not cause the hunger spikes or cortisol elevation typical of GHRP-6. It is not approved as a prescription medicine in most countries and exists primarily as a research chemical. Sourcing from reputable, third-party tested suppliers matters significantly for purity. This is general information only — peptide use should involve clinician guidance.