What is Ipamorelin?

Ipamorelin is a synthetic growth hormone secretagogue that acts through the ghrelin/GHS receptor pathway. It became notable because early pharmacology described selective GH release compared with older GHRPs. [2][5]

Its selectivity is the identity detail that made it popular. Ipamorelin was described as a GH secretagogue with less ACTH, cortisol, and prolactin activity than older GHRPs, which is why it is often framed as the cleaner GH-pulse member of the group. [2][5]

Ipamorelin is often discussed alongside CJC-1295, sermorelin, GHRP-2, and GHRP-6, but it is not a GHRH analog. Its identity is a GHRP/ghrelin-receptor agonist, usually encountered as an acetate salt in peptide-market products. [2][5]

What Ipamorelin is investigated for

Ipamorelin evidence is grouped by practical use case and injectable route context. Each use case separates confidence, human evidence, animal or mechanistic support, and the practical takeaway.

GH-axis stimulation and IGF-1 response

Injectable

58% Emerging

Human pharmacology supports selective GH-pulse stimulation; endpoint benefit still needs controlled outcome trials. [2][5]

Human evidence

Human pharmacology supports GH release, but outcome-level evidence for fat loss, lean mass, and recovery is limited. [2][5]

Animal / mechanistic evidence

Preclinical and pharmacology studies support a selective ghrelin-receptor mechanism. [2][5]

Postoperative GI recovery

Injectable

52% Emerging

Postoperative GI recovery has a randomized proof-of-concept signal and rodent ileus support, but it has not become a routine treatment standard. [12][11]

Human evidence

A randomized proof-of-concept study tested ipamorelin for postoperative ileus after bowel resection. [12][11]

Animal / mechanistic evidence

Rodent ileus models provide route-relevant preclinical support. [12][11]

Lean-mass and fat-loss support

Injectable

30% Limited

Lean-mass and fat-loss claims remain extrapolated from GH pharmacology and animal bone data. [6][8]

Human evidence

No controlled long-term human trial establishes improved lean mass or fat mass in non-deficient adults. [6][8]

Animal / mechanistic evidence

Animal studies support bone and anabolic-adjacent hypotheses through GH secretagogue biology. [6][8]

Recovery support

Injectable

18% Insufficient

Recovery support should remain an indirect GH-axis hypothesis, not a demonstrated ipamorelin outcome. [5][6]

Human evidence

No controlled human endpoint trial establishes improved training recovery, soreness, injury recovery, or return-to-training with ipamorelin. [2][5]

Animal / mechanistic evidence

The recovery rationale is indirect, relying on GH-secretagogue pharmacology and animal bone or anabolic-adjacent models. [6][8]

Sleep quality

Injectable

14% Insufficient

Sleep quality belongs as a reader intent, but the evidence is insufficient for a proven sleep benefit. [2][5]

Human evidence

Controlled ipamorelin trials have not established better sleep quality, sleep architecture, deep sleep, or insomnia outcomes. [2][5]

Animal / mechanistic evidence

Sleep positioning is extrapolated from GH-pulse timing rather than a validated sleep pathway. [5]

Evidence snapshot

Overall confidence

Emerging

55%

Ipamorelin has credible GH-secretagogue pharmacology and some human trial context. Common body-composition, recovery, and anti-aging claims remain ahead of outcome evidence. [2][12]

Overall confidence is a page-level composite, not an average; it weighs evidence quality, route/molecule match, and practical limitations.

50%

Human evidence

Emerging

Available human data include GH pharmacology and postoperative-ileus trials. They do not establish broad adult wellness, recovery, or anti-aging outcomes. [5][12]

46%

Animal / preclinical

Preliminary

Animal studies support GH-axis, bone, GI-motility, and cachexia hypotheses. These signals remain translational rather than confirmed user-facing outcomes. [6][8][11]

65%

Mechanism support

Moderate

Ghrelin-receptor agonism provides a direct mechanism for GH pulses and distinguishes ipamorelin from GHRH analogs. Downstream IGF-1 and glucose effects still need monitoring. [2][5]

Forms & administration

Ipamorelin is usually discussed as a short-acting injectable GH-axis protocol. Timing, food spacing, and lab context matter because the goal is a GH pulse. [5][12]

Injectable

Dosing & protocols

The notes below separate published trial design from commonly discussed cosmetic or compounded-use patterns. They are educational context only, not a prescription or product instruction.

Typical Range

Common injectable protocols use 200-300 mcg per dose. [5][12]

Frequency

1-3 times daily is the common app schedule because the peptide is short acting. [5][12]

Timing Considerations

Timing is commonly before bed or post-workout, away from food. Food timing matters because insulin and amino acids can blunt GH pulse interpretation. [5][12]

Cycle Length

Common cycles run 8-12 weeks. IGF-1, fasting glucose, water retention, appetite, sleep, and training notes are the usual reassessment points. [5][12]

What to expect

First week

Injectable GH-pulse use may first feel like changes in sleep depth, appetite, water retention, or recovery rhythm. [2]

Weeks 4-8

Waist, training tolerance, recovery notes, IGF-1, and fasting glucose become more informative once timing and food windows are consistent. [5]

After stopping

Water retention, appetite, and IGF-1-related markers often drift toward baseline after short-acting GH-axis stimulation ends. [2]

Safety profile

Injectable ipamorelin safety centers on water retention, appetite change, glucose and IGF-1 effects, injection quality, pregnancy avoidance, active malignancy caution, and sports prohibition. [2][17]

Common side effects

Water retention [2]
Appetite change [2]
Injection-site pain or swelling [19]

Cautions

Glucose monitoring [2][17]
Active malignancy [2][17]
Sports prohibited [22]

Who Ipamorelin is not for

Route-specific avoid and medical-review notes:

Active or recent cancer
Avoid outside specialist-directed care because GH/IGF-1 pathway stimulation can be inappropriate in malignancy contexts. [2][17]
Pregnancy or breastfeeding
Avoid because reproductive and lactation safety are not established for unapproved GH secretagogue use. [2][17]
Acromegaly or GH excess
Do not add GH secretagogue stimulation when GH/IGF-1 excess is present or suspected. [2][17]

Drug & supplement interactions

Documented interactions are separated from theoretical or route-specific cautions.

Theoretical interactions

Diabetes medications
Diabetes medications can become harder to adjust when injectable GH-axis stimulation shifts glucose control; this is a theoretical GH/insulin-axis caution. [2][17]
Other GH-axis agents
GHRH analogs, GHRPs, or HGH can add overlapping IGF-1, water-retention, glucose, and sports-risk concerns with injectable ipamorelin; this is a stack-level safety caution. [2][17]

Pairing notes

Commonly included in these stacks

CJC-1295 / Ipamorelin

CJC-1295 / Ipamorelin is a long-acting GH-axis stack built around a GHRH analog and a selective ghrelin-receptor growth-hormone secretagogue. The practical rationale is dual upstream stimulation of the GH/IGF-1 axis.

CJC-1295Ipamorelin

CJC-1295 no DAC / Ipamorelin

CJC-1295 no DAC / Ipamorelin is a short-pulse GH-axis stack. It combines a short-acting GHRH-side analog with Ipamorelin's ghrelin/GHS-receptor signal to organize discrete GH-release windows.

CJC-1295 (no DAC)Ipamorelin

Regulatory status

United States

Ipamorelin has no FDA-approved injectable human use as of 2026-06-21. FDA PCAC materials separately proposed against adding ipamorelin free base or acetate to the 503A Bulks List, so compounded availability should not be read as approval or safety clearance. [16][17][19]

Route	FDA drug approval	503A compounding
Injectable	Not Approved As of 2026-06-21, ipamorelin was not FDA-approved as an injectable drug. FDA PCAC materials evaluated ipamorelin-related bulk substances for 503A compounding, not for drug approval. [16][17]	Flagged FDA's October 29, 2024 PCAC materials proposed not including ipamorelin free base or ipamorelin acetate on the 503A Bulks List. That compounding review is not FDA approval or a safety clearance. [17][19]

Injectable

FDA drug approval

Not Approved

As of 2026-06-21, ipamorelin was not FDA-approved as an injectable drug. FDA PCAC materials evaluated ipamorelin-related bulk substances for 503A compounding, not for drug approval. [16][17]

503A compounding

Flagged

FDA's October 29, 2024 PCAC materials proposed not including ipamorelin free base or ipamorelin acetate on the 503A Bulks List. That compounding review is not FDA approval or a safety clearance. [17][19]

International

EU/Europe, UK, Canada, and Australia should be checked by local medicine and compounding rules; no approved therapeutic ipamorelin product was found in the reviewed official sources.

Sports & competition

WADA's 2026 Prohibited List treats growth hormone secretagogues and GHS mimetics as S2-prohibited; tested athletes should treat ipamorelin use as prohibited without a valid TUE. [22]

How it works

Ipamorelin is a ghrelin/GHS receptor agonist, so it acts upstream of growth hormone rather than replacing GH directly. Human pharmacology work supports a short GH pulse, with ipamorelin often described as more selective than older GHRPs for ACTH, cortisol, or prolactin effects. [2][5]

The practical mechanism is still GH-axis stimulation: repeated pulses can raise IGF-1 and connect the protocol to glucose, fluid-retention, and growth-signal monitoring. Injectable exposure does not prove body-composition, recovery, sleep, or longevity outcomes in people without route-matched trials. [5][17]

Research gaps & open questions

What the current literature has not yet settled about Ipamorelin:

Long-term human data for sleep, recovery, body composition, and metabolic safety are still needed. [2]

Head-to-head comparisons with GHRP-2, GHRP-6, hexarelin, and GHRH analogs should use outcome endpoints, not only GH pulses. [5]

Combination protocols with CJC-1295 need stack-level safety, IGF-1, glucose, and sports-risk review. [22]

Common questions

Is ipamorelin more selective than older GHRPs?

Yes, early pharmacology describes a cleaner GH-secretagogue profile, but injectable GH-axis stimulation still raises IGF-1, glucose, and fluid-retention questions. [2]

Is ipamorelin FDA-approved?

No. Ipamorelin has no FDA-approved injectable human use, and FDA PCAC materials proposed against adding ipamorelin to the 503A Bulks List. [16][17]

Is ipamorelin banned in tested sports?

Yes. WADA treats GH secretagogues and GHS mimetics such as ipamorelin as S2-prohibited without a valid TUE. [22]

Myths & misconceptions

Myth

Ipamorelin is side-effect free because it is selective.

Reality

It is cleaner than some older GHRPs, but it still stimulates the GH/IGF-1 axis and remains unapproved for wellness use. [2][17]

Myth

CJC-1295 plus ipamorelin is proven to replace HGH safely.

Reality

The stack uses different upstream signals, but downstream IGF-1 and glucose concerns still need monitoring and are not equivalent to approved GH therapy. [2]

History & discovery

Ipamorelin entered the GHRP field as a designed pentapeptide meant to keep growth-hormone release while reducing the ACTH, cortisol, and prolactin spillover seen with older secretagogues. [2][5]

The first pharmacology paper described ipamorelin as a selective GHRP-receptor agonist with GH release closer to GHRH-like endocrine selectivity. [2]

Human volunteer modeling characterized dose-response and GH release, giving ipamorelin a real pharmacology base without establishing a chronic-use indication. [5]

A randomized proof-of-concept trial tested ipamorelin for postoperative ileus after bowel resection, but this clinical thread did not produce an FDA-approved drug. [12][17]

Published research 22 studies

[1]

A new series of highly potent growth hormone-releasing peptides derived from ipamorelin.

Journal of medicinal chemistry, 1998 Sep 10. review.

[2]

Ipamorelin, the first selective growth hormone secretagogue.

European journal of endocrinology, 1998 Nov. review.

[3]

Pharmacokinetic evaluation of ipamorelin and other peptidyl growth hormone secretagogues with emphasis on nasal absorption.

Xenobiotica; the fate of foreign compounds in biological systems, 1998 Nov. review.

[4]

Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats.

Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society, 1999 Apr. animal.

[5]

Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers.

Pharmaceutical research, 1999 Sep. human clinical.

[6]

The GH secretagogues ipamorelin and GH-releasing peptide-6 increase bone mineral content in adult female rats.

The Journal of endocrinology, 2000 Jun. animal.

[7]

Highly potent growth hormone secretagogues: hybrids of NN703 and ipamorelin.

Bioorganic & medicinal chemistry letters, 2001 Jul 23. review.

[8]

The growth hormone secretagogue ipamorelin counteracts glucocorticoid-induced decrease in bone formation of adult rats.

Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society, 2001 Oct. animal.

[9]

Influence of chronic treatment with the growth hormone secretagogue Ipamorelin, in young female rats: somatotroph response in vitro.

Histology and histopathology, 2002. in vitro.

[10]

Mechanism of ipamorelin-evoked insulin release from the pancreas of normal and diabetic rats.

Neuro endocrinology letters, 2004 Dec. animal.

[11]

Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileus.

The Journal of pharmacology and experimental therapeutics, 2009 Jun. animal.

[12]

Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients.

International journal of colorectal disease, 2014 Dec. human clinical.

[13]

Determination of growth hormone releasing peptides metabolites in human urine after nasal administration of GHRP-1, GHRP-2, GHRP-6, Hexarelin, and Ipamorelin.

Drug testing and analysis, 2015 Oct. review.

[14]

The influence of ghrelin agonist ipamorelin acetate on the hypothalamic-pituitary-testicular axis in a cichlid fish, Oreochromis mossambicus.

Animal reproduction science, 2024 Sep. animal.

[15]

The growth hormone secretagogue receptor 1a agonists, anamorelin and ipamorelin, inhibit cisplatin-induced weight loss in ferrets: Anamorelin also exhibits anti-emetic effects via a central mechanism.

Physiology & behavior, 2024 Oct 1. animal.

[16]

Drugs@FDA/openFDA query for Ipamorelin

U.S. Food and Drug Administration / openFDA. database query.

[17]

October 29, 2024 Meeting of the Pharmacy Compounding Advisory Committee - FDA Briefing Document 4 - Ipamorelin

U.S. Food and Drug Administration, 2024-10-29. regulatory.

[18]

Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act

U.S. Food and Drug Administration, 2026-05-14. regulatory.

[19]

Compounding and the FDA: Questions and Answers

U.S. Food and Drug Administration. official guidance.

[20]

Safety and Efficacy of Ipamorelin for Management of Post-Operative Ileus

ClinicalTrials.gov. clinical trial registry.

[21]

Safety and Efficacy of Ipamorelin Compared to Placebo for the Recovery of Gastrointestinal Function

ClinicalTrials.gov. clinical trial registry.

[22]

The 2026 List of Prohibited Substances and Methods

World Anti-Doping Agency, 2026. regulatory.