Ipamorelin
PeptideThe marked discrepancy arises because community users predominantly report subjective effects (sleep, recovery) [c1, c2], while the medical evidence base lacks published RCTs for these indications [s7, s8]. Placebo effects and selection bias within user communities are likely.
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TL;DR
Ipamorelin selectively stimulates growth hormone release without meaningfully raising cortisol or prolactin — an appealing profile, but human evidence is thin: one PK/PD study and a small Phase II RCT on gastroparesis, with zero published RCTs on muscle gain or anti-aging as primary endpoints. Community reports on sleep, recovery, and body composition are consistently positive but reflect uncontrolled self-experimentation. In Germany, ipamorelin is not approved; use outside clinical trials is illegal, and WADA bans it year-round. Beyond legal risk, unregulated peptide sources carry real contamination and dosing hazards.
Description
Synthetic pentapeptide that selectively releases growth hormone from the pituitary without appreciably affecting cortisol or prolactin [s1, s2].
Ipamorelin (development code NNC 26-0161) is a synthetic pentapeptide with the amino acid sequence Aib-His-D-2-Nal-D-Phe-Lys-NH₂, derived from GHRP-1 [s1]. It belongs to the growth hormone secretagogue (GHS) class and acts as a selective agonist at the ghrelin/GHS receptor (GHS-R1a) in the pituitary gland [s1, s2]. Compared to other GH-releasing peptides such as GHRP-2 or GHRP-6, ipamorelin is distinguished by high selectivity: it primarily stimulates GH secretion without substantially elevating cortisol or prolactin levels [s3, s4]. This property designates it as the "first selective growth hormone secretagogue" [s2]. Structurally, D-amino acids and 2-naphthylalanine (2-Nal) confer enhanced metabolic stability and receptor selectivity to the molecule [s3]. Pharmacologically, ipamorelin has been investigated in Phase I human studies. GH secretion is pulsatile, with peak concentrations occurring within approximately one hour post-injection [s5, s6]. Ipamorelin is not FDA-approved for therapeutic use [s11] and is classified as a research chemical in Germany [s12]. It is prohibited by WADA [s13]. The clinical evidence base for ipamorelin in healthy humans is limited: no published RCTs exist examining muscle gain, body fat, or anti-aging endpoints as primary outcomes [s7, s8]. Available human studies are confined to PK/PD investigations and one Phase II study on postoperative gastroparesis [s5, s6, s9].
Legal Status (DE)
In Germany, ipamorelin is not approved as a medicinal product. It is classified as an unauthorized medicinal product or research chemical under the AMG (Medicinal Products Act). Use outside of clinical trials is not legal [s12]. Ipamorelin is also prohibited year-round by WADA (Category S2: Peptide Hormones, Growth Factors, Related Substances and Mimetics) [s13].
Mechanism of Action
As a ghrelin mimetic, ipamorelin binds specifically to the growth hormone secretagogue receptor 1a (GHS-R1a) in the pituitary gland [s1, s2]. This binding activates an intracellular signaling cascade via G-protein (Gq/11), leading to an increase in intracellular calcium and triggering pulsatile growth hormone (GH) secretion from somatotropic cells of the pituitary [s1, s2]. In contrast to GHRP-2 and GHRP-6, ipamorelin exhibits approximately 10-fold higher selectivity for GHS-R over other receptor pathways [s4]. As a result, activation of off-target pathways (cortisol, prolactin, and ACTH release) remains minimal [s3, s4]. The amount of GH released is dose-dependent up to a saturation dose; higher doses do not produce proportionally higher GH levels [s5]. GH stimulates hepatic synthesis of insulin-like growth factor 1 (IGF-1), which is considered responsible for many of the anabolic and tissue-regenerative effects [s2, s8]. The plasma half-life of ipamorelin is short (approximately 2 hours in animal models); the GH peak in humans occurs within approximately 60 minutes after subcutaneous injection [s5, s6].
Dosing
GH-Stimulation / allgemeine Anwendung (Forschungskontext)
- Dose
- 100–300 mcg per injection
- Frequency
- 1–3× täglich
- Route
- injektion-subkutan
- Duration
- 8–12 Wochen (Forschungsprotokoll)
- Timing
- Fasted, preferably before sleep or after training (at least 2–3 hours food abstinence)
- With food
- vermeiden
CJC-1295 + Ipamorelin Kombination (Community-Protokoll)
- Dose
- 100–200 mcg CJC-1295 (without DAC) + 200–300 mcg ipamorelin
- Frequency
- 1× täglich abends
- Route
- injektion-subkutan
- Duration
- 8–12 Wochen
- Timing
- Before sleep, fasted
- With food
- vermeiden
No officially established maximum dose for humans exists, as ipamorelin is not approved [s11, s12]. In PK/PD studies, doses up to 10 mcg/kg IV have been investigated [s5]. Community protocols rarely exceed 300 mcg per single dose [c2].
Subcutaneous injection requires aseptic technique. Ipamorelin must be reconstituted with sterile water or bacteriostatic water prior to use. Fasting before injection is important, as food intake (particularly carbohydrates and fats) inhibits GH secretion. No clinical dosing recommendation exists for routine use in humans [s12].
Calculate reconstitution, plan dosing, look up injection technique
Side Effects
| Side Effect | Frequency | Severity |
|---|---|---|
| Reaktionen an der Injektionsstelle (Rötung, leichte Schwellung, Schmerz) Typical for subcutaneous peptide injections; reported in short-term studies, no significant difference from placebo in clinical trials [s9]. | gelegentlich | leicht |
| Kopfschmerzen Reported in short-term clinical studies; transient and mild [s9, s10]. | gelegentlich | leicht |
| Flush / Hitzegefühl Community reports at higher doses (>300 mcg); mechanistically plausible via GH-mediated vasodilation [c1, c2]. | gelegentlich | leicht |
| Leichte Übelkeit oder Schwindel Documented in clinical studies; more frequent with intravenous than subcutaneous administration [s5, s9]. | gelegentlich | leicht |
| Wassereinlagerungen (Ödeme) GH-mediated fluid retention; recognized as a class effect of GH secretagogues, rarely explicitly reported in ipamorelin-specific studies [s10]. | selten | moderat |
| IGF-1-Erhöhung mit potenzieller Insulinresistenz Sustained IGF-1 elevation from chronic GH stimulation can impair insulin sensitivity; known with the related compound tesamorelin [s8, s10]. | theoretisch | moderat |
| Kortisol- und Prolaktin-Erhöhung Unlike GHRP-2/GHRP-6, no significant effect on cortisol or prolactin has been demonstrated in studies [s2, s3, s4]. | selten | leicht |
| Mögliche Begünstigung hormonabhängiger Tumoren (theoretisch) GH/IGF-1 elevation via secretagogues is theoretically risky in pre-existing neoplasms; no specific human data for ipamorelin [s10]. | theoretisch | schwer |
Contraindications
GH and IGF-1 elevation may theoretically promote tumor growth; class contraindication for GH secretagogues [s10].
No human safety data; animal studies insufficient for risk assessment [s10, s12].
GH secretagogues can reduce insulin sensitivity and raise blood glucose; regular glucose monitoring required [s8, s10].
Thyroid hormones influence the GH axis; uncontrolled hypothyroidism can attenuate the GH response [s10].
No pediatric safety data; uncontrolled GH stimulation with open epiphyseal growth plates is contraindicated [s10, s12].
Interactions
Synergistic
Combined administration of a GHRH analogue + GHS-R agonist results in synergistically increased GH secretion (dual pituitary stimulation) [s6, c1].
Analogous principle to CJC-1295; synergistic GH stimulation through combined GHRH and GHS-R activation is mechanistically plausible [s6].
Ipamorelin and BPC-157 are frequently combined to complement GH-mediated regeneration with the direct healing effects of BPC-157 on soft tissue and the gut. This combination is referred to as the "Wolverine Stack" and targets accelerated tissue regeneration.
TB-500 and ipamorelin are used together in the so-called "Wolverine Stack," as TB-500 promotes cell migration and soft tissue regeneration while ipamorelin stimulates GH secretion.
Ipamorelin/CJC-1295 and enclomiphene are combined in hormonal optimization, with enclomiphene targeting the testosterone axis and ipamorelin targeting the growth hormone axis – two complementary endocrine systems.
Caution
GH-induced insulin resistance may increase the dose requirements of antidiabetic agents; blood glucose monitoring is recommended [s8, s10].
Glucocorticoids inhibit GH secretion and may attenuate the effect of ipamorelin [s10].
Somatostatin directly inhibits GH secretion and antagonizes the effect of ipamorelin [s10].
Concurrent administration of ipamorelin and GHRP-2 may result in additive GHS-R1a stimulation. Unlike ipamorelin, GHRP-2 also increases cortisol and ACTH, which may potentiate adverse effects when combined.
The combination of ipamorelin with GHRP-6 may lead to enhanced appetite stimulation and elevated prolactin, as GHRP-6 — unlike ipamorelin — activates serotonin receptors that increase hunger.
Hexarelin is the most potent GHRP and binds CD36 receptors (cardiac scavenger receptor); combining it with ipamorelin increases the risk of receptor desensitization and cardiac effects.
Berberine significantly lowers blood glucose; since GH induced by ipamorelin can increase insulin resistance, berberine may partially compensate for this effect — the combined impact on glucose metabolism should be monitored.
Alpha-lipoic acid improves insulin sensitivity and lowers blood glucose. Since ipamorelin can increase insulin resistance via elevated GH, this combination may lead to unpredictable blood glucose fluctuations.
Studies
Tier A — High Evidence
Outcome: Time to tolerance of a normal meal after colorectal surgery (gastroparesis)
Effect Size: Ipamorelin group achieved meal tolerance earlier than placebo; difference not statistically significant; well tolerated [s9]
Outcome: Pharmacokinetics and GH release profile following i.v. ipamorelin
Effect Size: Dose-dependent GH secretion; peak concentration within 1h; no significant effect on cortisol/prolactin [s5]
Tier B — Moderate Evidence
Outcome: GH selectivity vs. cortisol/ACTH/prolactin compared to GHRP-2 and GHRP-6
Effect Size: Ipamorelin stimulates GH highly selectively without relevant cortisol or prolactin elevation [s2]
Outcome: Pharmacological model of GH pulses following ipamorelin
Effect Size: Plasma levels of ipamorelin persisted longer than GH levels; pulsatile GH kinetics well characterizable [s6]
Tier C — Low Evidence
Outcome: Postoperative gastroparesis following colorectal surgery
Effect Size: Results limitedly published; no statistically significant primary endpoint [s9]
Community Evidence
Top reported benefits
- Improved sleep quality (deeper sleep, more vivid dreams)
- Faster recovery after training
- Slight improvement in body composition over 8–12 weeks
- Better skin quality and general well-being
- Fewer side effects than GHRP-2 or GHRP-6
Top reported issues
- Lack of effect with suboptimal dosing or poor product quality
- Injection site reactions (redness, mild pain)
- Headaches and mild flushing at higher doses
- High costs and unreliable sources of supply
Many users combine ipamorelin without medical supervision with other peptides (primarily CJC-1295). The Pharmazeutische Zeitung explicitly warns of contaminants, dosing errors, and immunological reactions with self-reconstituted peptides from uncontrolled sources [s14]. WADA doping prohibition is largely disregarded in sports communities [s13, c4].
Scientific Sources
- Ipamorelin
Wikipedia contributors (2024). WikipediaDLink - CJC-1295 + Ipamorelin Side Effects: Trial Data (2026)
The Peptide Catalog (2026). thepeptidecatalog.comDLink - Is Ipamorelin FDA Approved? Regulatory Status Explained
Real Peptides (2025). realpeptides.coDLink - Ipamorelin: Wirkmechanismus, Dosierung und Legalität
Supplement Bewertung (2025). supplement-bewertung.comDLink - The Prohibited List 2025
World Anti-Doping Agency (2025). WADAALink - Peptid-Hype in Tech-Kreisen
Pharmazeutische Zeitung (2025). Pharmazeutische ZeitungBLink - Peptide legal in Deutschland? Rechtslage 2026
Peptide Culture (2026). peptide-culture.comDLink - Ipamorelin, the first selective growth hormone secretagogue
Raun K, Hansen BS, Johansen NL, et al. (1998). European Journal of EndocrinologyCPMID:9849822DOI - Ipamorelin Peptide — Growth Hormone Support
Paragon Sports Medicine (2026). paragonsportsmedicine.comDLink - Ipamorelin vs GHRP-2 vs GHRP-6: Complete Growth Hormone Secretagogue Research Comparison
Loti Labs (2025). lotilabs.comDLink - Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers
Gobburu JV, Agersø H, Jusko WJ, et al. (1999). Pharmaceutical ResearchBPMID:10496658DOI - Growth hormone secretagogues: history, mechanism of action, and clinical development
Ishida J, Saitoh M, Doehner W, et al. (2020). JCSM Rapid CommunicationsBDOI - Ipamorelin: Evidence, Safety, and What the Research Actually Shows
Peptide Garden (2025). peptidegarden.comDLink - Ipamorelin: Benefits, Dosing & Where to Buy (2026)
The Peptide Catalog (2026). thepeptidecatalog.comDLink - Safety and Efficacy of Ipamorelin Compared to Placebo for the Treatment of Postoperative Ileus
Ferring Pharmaceuticals (2013). ClinicalTrials.govBLink
Community Sources
Storage
Unopened
Lyophilized powder: store refrigerated at 2–8 °C, protect from light. Stable short-term without refrigeration (up to approximately 25 °C).
Opened
After reconstitution with bacteriostatic water: store at 2–8 °C, use within 28–30 days. After reconstitution with sterile water: use within 24–48 hours.
Notes
Avoid freezing the reconstituted solution. Minimize agitation (do not shake). Products from uncontrolled sources may contain contaminants [s14].