Ipamorelin — Research Reference
Ipamorelin is a synthetic pentapeptide (5 amino acids) and selective growth hormone (GH) secretagogue. It was first described in 1998 and is notable among growth hormone releasing peptides (GHRPs) for its high selectivity — research suggests it stimulates GH release without the significant co-elevation of cortisol, prolactin, or ACTH that characterises older members of the GHRP class such as GHRP-2 and GHRP-6.
Quick Reference
| Parameter | Reported Value |
|---|---|
| Full name | Ipamorelin |
| Amino acids | 5 |
| Molecular weight | ~711 Da |
| Half-life | ~2 hours (reported) |
| Common reported doses | 100–300 mcg per injection |
| Administration routes | Subcutaneous, intramuscular |
| Storage (lyophilized) | Refrigerator preferred; room temperature stable short-term |
| Storage (reconstituted) | Refrigerated; use within 4–6 weeks |
Overview
Ipamorelin belongs to the growth hormone releasing peptide (GHRP) class. It acts as an agonist at the ghrelin receptor (GHS-R1a), which is the primary signalling receptor for growth hormone secretagogues. Unlike endogenous ghrelin, ipamorelin is reported to stimulate GH release with a high degree of selectivity, with minimal observed effects on other pituitary hormones at research doses.
Key pharmacological characteristics investigated in research include:
- Selectivity: Reported to stimulate GH secretion without meaningful co-elevation of cortisol or prolactin, in contrast to GHRP-2 and GHRP-6
- Mechanism: Acts via the ghrelin receptor to trigger pulsatile GH release from the pituitary gland; the GH release is dose-dependent and additive with GHRH analogues
- Combination: Frequently researched in combination with CJC-1295 (a GHRH analogue) to produce synergistic GH release by acting on both the GHRH receptor and the ghrelin receptor simultaneously
Ipamorelin is not approved for human therapeutic use in any major jurisdiction and is classified as a research chemical. It appears on the WADA Prohibited List.
Reported Protocols
The following information represents commonly reported research ranges drawn from anecdotal accounts and available research literature. These are not medical recommendations.
Subcutaneous Protocol
Subcutaneous injection is the most commonly reported administration route. Commonly reported doses range from 100 mcg to 300 mcg per injection, administered two to three times daily.
- Dosing frequency: Two to three injections per day are the most commonly reported approach, typically timed around sleep, training, and fasting periods to maximise pulsatile GH output
- Fasting: Many anecdotal protocols describe injecting in a fasted state, as elevated insulin is reported to blunt GH release. A 2–3 hour fast prior to injection is commonly described
- Duration: Commonly reported research cycles range from 8 to 16 weeks, often followed by a similar off-period
Combination with CJC-1295
Ipamorelin is most frequently discussed in combination with CJC-1295 (without DAC / Mod GRF 1-29). The rationale reported in research accounts is that CJC-1295 acts on the GHRH receptor while ipamorelin acts on the ghrelin receptor — the two signals are reported to produce a synergistic GH pulse significantly larger than either alone. Commonly reported combination doses are 100–200 mcg of each compound per injection.
Before Sleep
Many anecdotal researchers describe ipamorelin as particularly useful when injected before sleep, as the largest natural GH pulse occurs during slow-wave sleep. Administration approximately 30 minutes before sleep is a commonly described approach.
Reported Effects
The following effects have been reported in preclinical research and anecdotal accounts. This list reflects the research landscape, not confirmed clinical outcomes.
Growth Hormone Release
Research has confirmed ipamorelin’s ability to stimulate pulsatile GH secretion from the pituitary gland in animal models. The resulting elevation in circulating GH subsequently triggers hepatic IGF-1 (insulin-like growth factor-1) production, which is proposed as the mediator of many downstream anabolic and recovery effects.
Recovery & Tissue Repair
Anecdotal reports suggest improvement in recovery time from physical training and musculoskeletal injury. This is attributed in anecdotal accounts to the role of GH and IGF-1 in protein synthesis, nitrogen retention, and collagen production.
Sleep Quality
Anecdotal reports frequently describe improvement in sleep quality, particularly sleep depth and vivid dreaming. This is consistent with the observation that natural GH secretion is highest during deep (slow-wave) sleep, and that GH secretagogue administration may augment this nocturnal pulse.
Body Composition
Research has investigated growth hormone secretagogues for their potential role in fat oxidation and lean mass preservation. Anecdotal reports describe modest reductions in body fat and improvements in muscle fullness over extended cycles.
Anti-aging
Research has investigated GH secretagogues in the context of age-related GH decline. GH secretion diminishes markedly with age (a process called somatopause), and secretagogues such as ipamorelin are sometimes researched as a means of partially restoring youthful GH pulse amplitude.
Reported Side Effects
Reported side effects in research and anecdotal accounts include the following. This list does not constitute a comprehensive safety profile and should not be interpreted as predictive of individual outcomes.
| Side Effect | Frequency Reported |
|---|---|
| Injection site redness or mild pain | Common (any SubQ/IM injection) |
| Mild flushing or warmth | Occasionally reported shortly after injection |
| Headache | Occasionally reported; often transient |
| Water retention | Occasionally reported at higher doses |
| Fatigue | Rare |
| Tingling or numbness | Rare; associated with elevated GH levels |
Note: Unlike GHRP-2 and GHRP-6, ipamorelin is reported in the research literature to produce minimal cortisol or prolactin elevation at standard research doses. Increased appetite — a well-characterised effect of GHRP-6 — is not prominently reported with ipamorelin.
The compound has not undergone comprehensive human safety trials.
Storage & Handling
Lyophilized Powder (Unreconstituted)
- Room temperature: Reported stable for up to 3 months when kept away from light and moisture
- Refrigerator (2–8°C): Preferred for extended storage; commonly reported stable for 12 months or more
- Freezer: Acceptable for long-term storage; avoid repeated freeze-thaw cycles
- Light sensitivity: Store in an opaque or amber vial; avoid direct light exposure
Reconstituted Solution
- Refrigerator (2–8°C): Use within 4–6 weeks of reconstitution
- Do not freeze a reconstituted solution
- Bacteriostatic water (BAC water) is the standard diluent; the benzyl alcohol preservative extends refrigerated shelf life
- Discard if the solution becomes cloudy, discoloured, or shows particulate matter
Reconstitution
Add bacteriostatic water slowly to the lyophilized vial along the inside wall. Swirl gently — do not shake. See the Reconstitution Guide for step-by-step instructions.
Frequently Asked Questions
Why is ipamorelin preferred over GHRP-2 or GHRP-6? Ipamorelin is reported to produce selective GH stimulation with minimal co-elevation of cortisol and prolactin, which are observed with GHRP-2 and GHRP-6 at higher doses. Additionally, the strong appetite stimulation associated with GHRP-6 is not prominently reported with ipamorelin. For researchers seeking isolated GH stimulation with a cleaner side effect profile, ipamorelin is frequently preferred in anecdotal research accounts.
Should ipamorelin be injected fasted? Many anecdotal research protocols recommend injection in a fasted state, as elevated insulin and blood glucose are reported to blunt GH secretagogue response. A 2–3 hour fast is commonly described. This is not universally applied in all research accounts.
What is the difference between ipamorelin alone and the ipamorelin/CJC-1295 combination? Ipamorelin acts at the ghrelin receptor; CJC-1295 acts at the GHRH receptor. Using both simultaneously targets two independent pathways for GH release and is reported in anecdotal accounts to produce a synergistic GH pulse. The combination is the most commonly described approach in the research community.
How long should a research cycle run? Commonly reported cycles range from 8 to 16 weeks. Some anecdotal researchers describe continuous use over longer periods; others follow a cycle and off-cycle structure. There is limited long-term human safety data to guide this.
Related Pages
Goals: Muscle Growth · Sleep · Performance
Class: GHRPs — Growth Hormone Releasing Peptides
Comparisons: Ipamorelin vs CJC-1295 · Ipamorelin vs Sermorelin · Ipamorelin vs GHRP-2
Stacks: CJC-IPA
References & Further Reading
- Raun K, et al. (1998). Ipamorelin, the first selective growth hormone secretagogue. European Journal of Endocrinology, 139(5), 552–561. PubMed →
- Johansen PB, et al. (1999). Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats. Growth Hormone & IGF Research, 9(2), 106–113. PubMed →
- Bowers CY. (1998). Growth hormone-releasing peptide (GHRP). Cellular and Molecular Life Sciences, 54(12), 1316–1329. PubMed →