Ipamorelin
NNC 26-0161 · Ipamorelin acetate
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Ipamorelin is a synthetic pentapeptide and selective growth hormone secretagogue receptor (GHS-R1a) agonist. Its sequence is Aib-His-D-2-Nal-D-Phe-Lys-NH₂. Unlike earlier GHRPs (GHRP-2, GHRP-6), ipamorelin is highly selective for GHS-R1a without elevating ACTH, cortisol, prolactin, or aldosterone at therapeutic doses — the most common reason it is preferred over non-selective GHRPs. It stimulates pulsatile growth hormone release from pituitary somatotropes through the ghrelin receptor pathway, distinct from the GHRH receptor pathway that sermorelin and CJC-1295 engage. This complementarity is why ipamorelin is most commonly stacked with CJC-1295: the GHRH analogue amplifies the GH pulse amplitude while ipamorelin amplifies pulse frequency via a different receptor, producing an additive secretagogue effect documented in the Teichman 2006 phase I/II trial.
In-depth Research Guide
Ipamorelin + CJC-1295: The Research Behind the Most-Used Growth Hormone Stack
In-depth Research Guide
Ipamorelin vs CJC-1295: Mechanism, Dosing, and Why Most Protocols Combine Them
Teichman et al. (JCEM, 2006; PubMed 16352683) remains the definitive human pharmacology study: CJC-1295 (with DAC) in 57 healthy adults produced 2–10× GH elevation and 1.5–3× IGF-1 elevation sustained for 9–11 days. Ipamorelin was studied alongside as a GHS-R1a component. The combination produces additive effects through dual receptor engagement. Human data for ipamorelin specifically (without the CJC stack) is limited. Both compounds removed from FDA Category 2 September 2024; WADA prohibits both in sport.
IpamorelinAlso known as: NNC 26-0161, Ipamorelin acetate
Mechanism of Action
Ipamorelin is a synthetic pentapeptide and selective growth hormone secretagogue receptor (GHS-R1a) agonist. Its sequence is Aib-His-D-2-Nal-D-Phe-Lys-NH₂. Unlike earlier GHRPs (GHRP-2, GHRP-6), ipamorelin is highly selective for GHS-R1a without elevating ACTH, cortisol, prolactin, or aldosterone at therapeutic doses — the most common reason it is preferred over non-selective GHRPs. It stimulates pulsatile growth hormone release from pituitary somatotropes through the ghrelin receptor pathway, distinct from the GHRH receptor pathway that sermorelin and CJC-1295 engage. This complementarity is why ipamorelin is most commonly stacked with CJC-1295: the GHRH analogue amplifies the GH pulse amplitude while ipamorelin amplifies pulse frequency via a different receptor, producing an additive secretagogue effect documented in the Teichman 2006 phase I/II trial.
Reported Research Benefits
- Selective GHS-R1a agonism without ACTH, cortisol, or prolactin elevation — confirmed in human pharmacology studies
- Pulsatile GH release: preserves natural GH secretion rhythm (unlike continuous exogenous HGH)
- Stacked with CJC-1295 DAC: Teichman 2006 showed 2–10× GH elevation sustained for 9–11 days
- Improved body composition: lean mass gain, fat mass reduction in GH secretagogue literature
- Sleep quality improvement: GH secretion peaks during slow-wave sleep, enhanced by ipamorelin protocols
- Shorter half-life (~2 hours) allows dosing flexibility and rapid clearance vs long-acting alternatives
Dosing Protocol & Reconstitution
Reported Research Dosing — Not Clinical Recommendations
Ipamorelin is most commonly dosed alongside CJC-1295 because the two peptides hit independent receptors (ghrelin and GHRH) and their GH-releasing effects add together. Monotherapy is reasonable for an initial cycle to establish tolerability.
Ipamorelin Monotherapy
| Dose | Frequency | Timing | Typical Cycle |
|---|---|---|---|
| 200 mcg | 1× daily | Pre-bed | 4–6 weeks (first cycle) |
| 200–300 mcg | 2–3× daily | Waking, post-workout, pre-bed | 8–12 weeks |
The pre-bed dose is universally included because natural GH pulse is largest overnight, and ipamorelin compounds with the endogenous pulse.
Ipamorelin + CJC-1295 (non-DAC / Mod GRF 1-29) Stack
| Peptide | Dose | Frequency | Timing |
|---|---|---|---|
| Ipamorelin | 200 mcg | 1–3× daily | Fasted windows, pre-bed |
| CJC-1295 non-DAC | 100–200 mcg | 1–3× daily (same injections) | Co-administered with ipamorelin |
Both peptides have short half-lives (~2 hours and ~30 minutes respectively), so pulsatile dosing preserves pituitary responsiveness. The two are typically drawn into the same insulin syringe and injected together.
Ipamorelin + CJC-1295 DAC Stack
| Peptide | Dose | Frequency | Timing |
|---|---|---|---|
| Ipamorelin | 200–300 mcg | 1× daily | Pre-bed |
| CJC-1295 DAC | 1–2 mg | Once weekly | Any day |
CJC-1295 DAC has a 6–8 day half-life via albumin binding. Weekly dosing produces sustained GHRH signalling (not pulsatile). This trades dosing convenience for loss of natural pulsatility — see the Ipamorelin vs CJC-1295 comparison for the pulsatile-vs-sustained trade-off.
Administration
- Route: subcutaneous injection
- Site rotation: abdomen, thigh — rotate
- Timing principles:
- Pre-bed dose aligns with natural nocturnal GH surge
- Fasted state is preferred (carbohydrate/insulin spikes blunt GH response)
- Space injections at least 3 hours from heavy meals
Reconstitution
Ipamorelin:
- 5 mg vial + 2 mL bacteriostatic water = 2,500 mcg/mL (200 mcg per 0.08 mL on U-100 insulin syringe = 8 units).
CJC-1295 (non-DAC or DAC):
- 5 mg vial + 2 mL bacteriostatic water = 2,500 mcg/mL (100 mcg per 0.04 mL = 4 units on U-100).
Both store refrigerated at 2–8°C after reconstitution. Stable for 28 days. Do not freeze.
Cycle Duration and Monitoring
- Typical cycle: 12–24 weeks
- Monitoring: baseline and 10–12 week IGF-1 measurement is the most common biomarker
- Washout: 4–8 weeks between cycles is standard practitioner practice
Contraindications
- Active malignancy — GH/IGF-1 axis elevation is a theoretical oncogenic concern
- Diabetes mellitus — GH elevates insulin resistance; monitor glucose
- Cardiovascular disease — sustained IGF-1 elevation has unclear long-term cardiac implications
- Pregnancy and lactation — no data; avoid
- Pediatric use — not indicated outside controlled GH-deficiency treatment
Regulatory Status (as of April 2026)
Both ipamorelin and CJC-1295 were removed from the FDA Section 503A bulks list in September 2024, restricting compounding-pharmacy access. Current status remains research-compound in most jurisdictions. WADA prohibits both in competitive sport.
Research Notes
Teichman et al. (JCEM, 2006; PubMed 16352683) remains the definitive human pharmacology study: CJC-1295 (with DAC) in 57 healthy adults produced 2–10× GH elevation and 1.5–3× IGF-1 elevation sustained for 9–11 days. Ipamorelin was studied alongside as a GHS-R1a component. The combination produces additive effects through dual receptor engagement. Human data for ipamorelin specifically (without the CJC stack) is limited. Both compounds removed from FDA Category 2 September 2024; WADA prohibits both in sport.
Research Summary
Teichman et al. (JCEM 2006) phase I/II human data: CJC-1295 produced 2–10× GH and 1.5–3× IGF-1 elevation for 9–11 days. Ipamorelin as selective GHRP lacks cortisol/ACTH activation. Both compounds FDA Category 2 as of September 2024 (removed from compounding list). Reclassification to Category 1 expected under RFK/HHS review. WADA prohibited.
Side Effects & Safety
Reported in clinical series (injection-based protocols): injection site reactions (mild erythema, most common), transient headache, mild fluid retention at initiation. GH-class effects at higher doses: increased hunger, mild joint aches (water retention), transient insulin resistance — monitor fasting glucose. No ACTH, cortisol, or prolactin elevation at therapeutic doses (key selectivity advantage over GHRP-2/GHRP-6). Long-term safety data (>1 year) not available from published RCTs. WADA prohibited.
Stability & Storage
Lyophilised powder: stable at -20°C for 2–3 years. After reconstitution with bacteriostatic water: store at 4°C, use within 21–28 days. Sensitive to repeated freeze-thaw cycles.
Molecular Data
- Sequence
- Aib-His-D-2-Nal-D-Phe-Lys-NH₂ (Aib = α-aminoisobutyric acid; D-2-Nal = D-2-naphthylalanine)
- Molecular Formula
- C38H49N9O5
- Molecular Weight
- 711.9 Da
- CAS Number
- 170851-70-4
- Half-Life
- ~2 hours (subcutaneous)
Primary literature: https://pubmed.ncbi.nlm.nih.gov/16352683/