Section 01
What it's used for
Age-Related GH Decline
Human data on ipamorelin come from one study in young healthy men, not older ones, and skipped daily GH rhythms. Its selective GH effect, without raising cortisol, was shown in rats and pigs, not people. No trial tested age-related decline.
▸Clinical wording
Human data on ipamorelin come from a pharmacokinetic-pharmacodynamic study in young healthy male volunteers, not aging adults, and this study did not test circadian GH rhythms or somatopause-related endpoints. Ipamorelin's selective stimulation of GH release, without raising cortisol, prolactin, or ACTH, was characterized in rat and swine studies, not in humans. No human trial has tested ipamorelin specifically for age-related GH decline.
Recovery After Surgery
In a phase 2 trial, 114 bowel-surgery patients got IV ipamorelin (0.03 mg/kg) for slowed gut recovery. Time to first meal was numerically shorter, 25.3 vs 32.6 hours, but not statistically significant (p=0.15); no other outcome differed.
▸Clinical wording
A phase 2, randomized, placebo-controlled trial tested intravenous ipamorelin (0.03 mg/kg) in 114 patients undergoing bowel resection surgery for postoperative ileus. The median time to first tolerated meal was numerically shorter with ipamorelin (25.3 hours) than with placebo (32.6 hours), but the difference was not statistically significant (p=0.15), and no significant differences were found on the trial's other efficacy endpoints.
Body Composition Claims
In a mouse study, ipamorelin unexpectedly raised body fat and food intake via a GH-independent pathway, not reducing fat. No human body-composition trial exists, alone or with CJC-1295, so claims of fat loss in people are unsupported.
▸Clinical wording
In a mouse study, ipamorelin unexpectedly increased relative body fat and food intake through a GH-independent mechanism, rather than reducing fat mass. No human body-composition trial of ipamorelin, alone or combined with a GHRH analog such as CJC-1295, has been conducted, so claims of lean-mass gain or fat-mass reduction in humans are not supported by published data.
Bone Density Research
Growth hormone and IGF-1 regulate bone metabolism. In preclinical (lab and animal) models, ipamorelin increased bone density and bone-formation markers (osteocalcin, P1NP), suggesting possible use in osteoporosis and fracture healing.
▸Clinical wording
GH and IGF-1 are critical regulators of bone metabolism. Ipamorelin research shows increased bone mineral density and improved bone formation markers (osteocalcin, P1NP) in preclinical models, suggesting potential applications in osteoporosis prevention and fracture healing.
Sleep Quality and Recovery
Growth hormone release is closely tied to deep, slow-wave sleep. Ipamorelin taken before bed is being studied for boosting sleep-related growth-hormone pulses, improving sleep-quality measures, and speeding recovery from physical exertion.
▸Clinical wording
GH release is closely linked to slow-wave sleep. Ipamorelin administered before bedtime has been studied for enhancing sleep-related GH pulses, improving sleep quality metrics, and accelerating recovery from physical exertion.
Muscle Injury Recovery Claims
Claims that ipamorelin speeds muscle repair after injury appear in vendor sources, not published research. A PubMed search found no study testing ipamorelin in a muscle-injury model; related work concerns IGF-1 generally, not this peptide.
▸Clinical wording
Claims that ipamorelin accelerates skeletal muscle regeneration after injury, through satellite cell activation or IGF-1-dependent mechanisms, appear in vendor and community sources but not in the published literature. A search of PubMed found no study testing ipamorelin itself in a muscle-injury or regeneration model; the related literature that does exist concerns IGF-1 in general, not ipamorelin specifically. No published evidence, at the cell-culture, animal, or human level, supports this application for ipamorelin.
Section 02
Mechanism of Action
Triggering release of stored hormone
- It binds the hunger-hormone receptor found mainly on hormone-making pituitary cells.
- Binding sets off a chain that frees calcium stored inside the cell.
- That calcium release pushes packets of growth hormone out of the cell.
▸Clinical wording
GHS-R1a Receptor Activation
Ipamorelin binds to the growth hormone secretagogue receptor type 1a (GHS-R1a), a G-protein coupled receptor primarily expressed on somatotroph cells of the anterior pituitary. Receptor activation stimulates the Gq/11 signaling cascade, leading to phospholipase C activation, IP3-mediated calcium release from intracellular stores, and subsequent growth hormone vesicle exocytosis.
Hitting one target and not others
- Its selectivity comes from binding this one receptor and barely touching related ones.
- Studies report no meaningful rise in stress hormones even at 100 times the effective dose.
- The source calls this a unique feature among growth hormone releasers.
▸Clinical wording
Selective GH Release
Ipamorelin's selectivity stems from its specific receptor binding profile — it activates GHS-R1a at the pituitary with high potency but has minimal activity at other receptor subtypes involved in ACTH/cortisol release. Studies demonstrate that even at doses 100-fold above the GH-stimulating dose, ipamorelin does not significantly increase cortisol or ACTH levels — a unique feature among GH secretagogues.
Releasing hormone in natural bursts
- Injected growth hormone gives sustained above-normal levels, while this peptide triggers bursts instead.
- The burst pattern follows the body's natural rhythm of hormone release.
- Keeping that rhythm is described as preserving the receptor sensitivity continuous exposure erodes.
▸Clinical wording
Pulsatile Secretion Pattern
Unlike exogenous growth hormone administration (which produces sustained supraphysiological levels), ipamorelin stimulates pulsatile GH release that preserves the natural rhythm of GH secretion. This pulsatile pattern maintains GH receptor sensitivity and downstream IGF-1 signaling without the receptor desensitization seen with continuous GH exposure.
Two triggers that add up
- The natural releasing hormone tells pituitary cells to make more growth hormone.
- This peptide instead releases hormone already stored, through a separate internal route.
- Given together they produce more release than the two effects added separately.
▸Clinical wording
Synergy with GHRH
Ipamorelin works synergistically with growth hormone releasing hormone (GHRH) and its analogs. While GHRH activates GH synthesis and the cAMP/PKA pathway in somatotrophs, ipamorelin releases stored GH through the calcium/IP3 pathway. Combined administration produces GH release greater than the sum of individual effects.
Working around the body's brake
- It partly counters somatostatin, the natural signal that blocks growth hormone release.
- That allows hormone release even when the braking signal is high.
- The result is described as more consistent stimulation across different body states.
▸Clinical wording
Somatostatin Functional Antagonism
Ipamorelin partially antagonizes the inhibitory effect of somatostatin on GH release, allowing for GH secretion even during periods of high somatostatin tone. This contributes to more consistent GH stimulation across different physiological states.
Section 03
Biological Pathways
- Gq/11-PLC-IP3/DAG PathwayGHS-R1a couples to Gq/11, activating PLC to cleave PIP2 into IP3 and DAG; IP3 releases calcium from the ER while DAG activates PKC, triggering GH granule exocytosis from somatotroph cells.
- GH/IGF-1 AxisGH activates JAK2/STAT5 in hepatocytes, stimulating hepatic IGF-1 synthesis; IGF-1 then activates PI3K/Akt and MAPK/ERK in target tissues, promoting protein synthesis, proliferation, and metabolic effects.
- mTOR/p70S6K Protein SynthesisGH and IGF-1 signaling converge on mTOR, activating p70S6K and 4E-BP1 to enhance ribosomal protein synthesis, the primary route for ipamorelin-stimulated muscle accretion and tissue repair.
- Lipolytic PathwayGH activates hormone-sensitive lipase in adipocytes via a JAK2-mediated, IGF-1-independent mechanism, stimulating lipolysis and favorable fat-to-muscle body composition.
Section 04
Dosage Information
Aib-His-D-2Nal-D-Phe-Lys-NH2| Route / system | Context | Range studied | Limitation |
|---|---|---|---|
| Intravenous — stalled gut after surgery | Phase 2 trial, 114 patients after bowel surgery | 0.03 mg/kg twice a day by drip on days 1–7 after surgery — about 2.1–2.7 mg per dose for a 70–90 kg adult | It missed: 25.3 hours to a first tolerated meal against 32.6 on placebo, p = 0.15. A week of drips into a freshly operated gut, not a growth-hormone study. |
| Intravenous — dose-finding | Phase 2, 320 patients after bowel surgery | 0.03 mg/kg twice a day, 0.06 mg/kg twice a day and 0.06 mg/kg three times a day by drip — up to about 16 mg a day at 90 kg | Completed in 2014; no results were ever posted and the programme stopped there. The highest doses ever given to people, and nobody reported how they turned out. |
| Intravenous — single dose | Phase 1 growth-hormone response in healthy men | Single 15-minute drips of 3–100 µg/kg (4.21–140.45 nmol/kg) — 0.2–9 mg at 70–90 kg; each gave one growth-hormone peak near 40 min | One drip per person. It measured how fast growth hormone rises and falls; it fixes no daily dose and no duration, and follows nobody past that same day. |
| Subcutaneous — self-administration | Circulating practice, often combined with CJC-1295 | 200–300 µg per day, in blocks of 8–12 weeks with 4 weeks off — roughly 2–4 µg/kg for a 70–90 kg adult | Circulating practice, not a finding: no trial ever injected ipamorelin under the skin, and both human trials on record were about the bowel, not growth hormone. |
Results
Syringe Fill Level (100u syringe)
Set positive values for: Recommended dose per kg.
Research Use Only. This information is for educational and research purposes only. Not intended for medical advice or self-medication.
Section 05
Protocols
- Protocol 01
CJC-1295 + Ipamorelin Stack
The most popular GH secretagogue stack. Synergistic effects for fat loss, muscle gain, recovery, and anti-aging.
- Focus
- Sport & Performance
- Level
- Intermediate
- Duration
- 3–6 months
- Protocol 02
Comprehensive Longevity Stack
Multi-peptide anti-aging protocol combining telomerase activation, mitochondrial support, and GH optimization.
- Focus
- Anti-Aging
- Level
- Advanced
- Duration
- 3–6 months
Section 06
Stability & Storage
Lyophilised powder
Kept at −20 °C for long-term stability (18–24 months) or at 2–8 °C for about 3–6 months, shielded from light, heat, and moisture. It is usually reconstituted with bacteriostatic water, added gently down the inner wall of the vial rather than shaken in.
After reconstitution
The solution should stay clear and colourless — cloudiness or particles signal degradation. It is kept at 2–8 °C, used within 21–28 days, and protected from freezing and vigorous shaking.
Section 07
Side Effects & Precautions
Reported effects with ipamorelin are mostly injection-site reactions and short-lived, growth-hormone-related symptoms; most resolve on their own or ease with a lower dose. Ipamorelin also differs from other GH-releasing peptides in how it affects appetite, cortisol, and prolactin.
Injection Site Reactions
Mild redness, swelling, or itching at the injection site is common and typically self-limiting. Rotating injection sites reduces local irritation.
Lightheadedness and Headache After Injection
Transient lightheadedness or mild headache can follow injection, possibly linked to short-term blood sugar changes or growth hormone effects on brain blood vessels. It usually resolves within 30-60 minutes.
Fluid Retention and Nerve Symptoms
- Mild fluid retention (swelling in the hands and feet) can occur, especially in the first weeks; it is a class effect of GH stimulation that eases with time.
- The fluid can press on the wrist's median nerve, causing carpal-tunnel-like numbness and tingling; this is dose-dependent and eases with a lower dose.
Compared With Other GH-Releasing Peptides
Ipamorelin raises appetite far less than GHRP-6, though some users still report mild increases, likely via residual GHS-R1a activity in the brain's hunger centers (hypothalamus). Unlike GHRP-2 and GHRP-6, it does not meaningfully raise cortisol or prolactin at standard GH-stimulating doses.
Section 08
Regulatory Status
It reached an Investigational New Drug status and completed Phase 2 trials for one indication, but development stopped there — no regulator has cleared it for a marketed product.
FDA / United States
Not approved; IND status only
Ipamorelin reached Investigational New Drug status and completed a Phase 2 trial for post-operative ileus, run under the name TZP-101 by Tranzyme Pharma. Development did not continue into Phase 3, and no application for approval has ever been filed.
Research chemical status
Sold as a lab reagent, not a drug
Peptide synthesis companies sell ipamorelin for laboratory research only. No country has approved it for human therapeutic use, and none of these products carries a pharmaceutical quality standard or an approved dose.
WADA
Prohibited under category S2
The WADA Prohibited List names ipamorelin explicitly as a growth hormone secretagogue in section S2.2.4. The ban runs in and out of competition, and LC-MS/MS testing can detect ipamorelin and its metabolites in urine for several days after use.
Regulatory status differs between countries and changes over time. An IND number or a completed trial phase is not an approval — check the current rules of your own regulator and, for athletes, the current WADA list before relying on any of this.
Section 09
Research Studies
- [1]Ipamorelin, the first selective growth hormone secretagogueRaun K, Hansen BS, Johansen NL, et al. · European Journal of Endocrinology · 1998
- [2]Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in ratsJohansen PB, Nowak J, Skjaerbaek C, et al. · Growth Hormone & IGF Research · 1999
- [3]Pharmacokinetic-Pharmacodynamic Modeling of Ipamorelin, a Growth Hormone Releasing Peptide, in Human VolunteersGobburu JVS, Agersø H, Jusko WJ, et al. · Pharmaceutical Research · 1999
- [4]The GH secretagogues ipamorelin and GH-releasing peptide-6 increase bone mineral content in adult female ratsSvensson J, Lall S, Dickson SL, et al. · Journal of Endocrinology · 2000
- [5]The growth hormone secretagogue ipamorelin counteracts glucocorticoid-induced decrease in bone formation of adult ratsAndersen NB, Malmlöf K, Johansen PB, et al. · Growth Hormone & IGF Research · 2001
- [6]Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patientsBeck DE, Sweeney WB, McCarter MD · International Journal of Colorectal Disease · 2014
- [7]A Receptor in Pituitary and Hypothalamus That Functions in Growth Hormone ReleaseHoward AD, Feighner SD, Cully DF, et al. · Science · 1996
- [8]Peptidomimetic Regulation of Growth Hormone SecretionSmith RG, Van der Ploeg LHT, Howard AD, et al. · Endocrine Reviews · 1997
- [9]Growth Hormone (GH)-Releasing Peptide Stimulates GH Release in Normal Men and Acts Synergistically with GH-Releasing HormoneBowers CY, Reynolds GA, Durham D, et al. · Journal of Clinical Endocrinology & Metabolism · 1990
- [10]Influence of chronic treatment with the growth hormone secretagogue Ipamorelin, in young female rats: somatotroph response in vitroJiménez-Reina L, Cañete R, de la Torre MJ, Bernal G · Histology and Histopathology · 2002
Section 10
Frequently Asked Questions
Every human study of ipamorelin used single or short intravenous dosing, not the subcutaneous self-injection or the CJC-1295 combination that circulate in practice — a single-dose study measured a growth-hormone peak about 40 minutes after infusion, and a phase 2 trial in postoperative bowel-surgery patients missed its primary endpoint (25.3 hours to first meal versus 32.6 on placebo, p=0.15). No human trial has tested ipamorelin alone or combined with CJC-1295 for muscle, fat loss or sleep; those effects rest on animal data and the drug's known selectivity for growth-hormone release, not a human outcome trial.
In the one dose-finding study in healthy men, a single intravenous infusion produced a growth-hormone peak around 40 minutes later — but that measured a single hormone spike from a single dose, not any downstream effect like muscle or sleep changes. No study has measured how long it takes for ipamorelin, taken daily or combined with CJC-1295, to produce a noticeable outcome.
Reported effects are mostly mild and local: injection-site redness or itching, transient head rush or headache resolving within an hour, and fluid retention that can produce carpal-tunnel-like numbness or tingling in the hands during initial use. Unlike older secretagogues such as GHRP-2 and GHRP-6, ipamorelin does not meaningfully raise cortisol or prolactin even at high doses, which is its main safety distinction within this drug class. Mild appetite stimulation has also been reported, though less than with GHRP-6.
Ipamorelin has never been approved by the FDA or any regulator; it holds only Investigational New Drug status and completed Phase 2 testing for post-surgical bowel recovery before development stopped, so it is sold as a research chemical rather than a medicine. WADA prohibits it under category S2, banned both in and out of competition, and it can be detected in urine by LC-MS/MS for several days after use.
This has not been studied. No published trial followed people after stopping ipamorelin — the surgical trial tracked patients for about a week after seven days of dosing, and the single-dose study measured one growth-hormone spike on the day it was given. What happens with longer, self-administered use, and after stopping it, has not been documented in the literature.
As lyophilised powder it is stable roughly 18 to 24 months at −20 °C, or 3 to 6 months at 2–8 °C, shielded from light, heat and moisture, and is usually reconstituted with bacteriostatic water added gently rather than shaken in. The reconstituted solution should stay clear and colourless — cloudiness signals degradation — and is kept at 2–8 °C, used within 21 to 28 days, and protected from freezing.