Peptide LibraryRelamorelin
Also known as: RM-131, BIM-28131, Ghrelin analog
Relamorelin (also called RM-131 or BIM-28131) is an investigational ghrelin analog in the Growth Hormone Secretagogue class. Relamorelin is a synthetic pentapeptide agonist at growth hormone secretagogue receptor 1a, developed principally for its gastrointestinal rather than endocrine activity. Ghrelin receptors are expressed on enteric neurons, and their activation accelerates gastric emptying and increases antral contractility.
For research use only.
Key Facts
- CAS
- 661472-41-9
- Molecular Weight (MW)
- 790.97 g/mol
- Half-life
- Not firmly established in public sources; studied as short-acting sc peptide
- FDA status
- Investigational New Drug (IND)
- Evidence level
- Clinical Trial Evidence
- Human dose established
- Yes
- Administration Route
- Subcutaneous
- Frequency
- Twice daily
- Last updated
- Nov 7, 2026
- Reviewed
- Nov 7, 2026
- Targets
- GHSR
Research summary
Investigational pentapeptide ghrelin receptor agonist developed principally for its gastrointestinal rather than endocrine effects. Ghrelin receptors on enteric neurons accelerate gastric emptying when activated, and relamorelin has been studied mainly in diabetic gastroparesis, where delayed emptying drives the symptoms. Clinical development has been mixed and it is not FDA-approved for any indication.
Research evidence
- Regulatory review (FDA label)None in reviewed sources
- Controlled human trials4 reviewed sources
- Early or uncontrolled human studiesNone in reviewed sources
- Lab & animal studiesNone in reviewed sources
How it works
Each step shows whether the sources Peptide Library has reviewed include that kind of research. Counts are reviewed sources, not every study ever published. Reviews and programme summaries that describe human use are shown as "reported", not as trials, and registered trials without published results are listed but not counted. A higher step means research has progressed further; it does not mean a compound works better or is safer. Compounds whose evidence has not been reviewed yet show "Not reviewed" instead of a guess.
Peptide Library's Relamorelin profile summarises 5 cited studies listed in the Science section, the compound's regulatory status, and research-protocol parameters reported for it. It is a research reference, not medical advice.
Relamorelin dosage evidence
Relamorelin has no approved dosage. Human dosing comes from trials in diabetic gastroparesis: the phase 2b trial gave 10, 30 or 100 mcg injected under the skin twice a day for 12 weeks and reduced core symptoms against placebo, and phase 3 trials used 10 mcg twice a day. The phase 3 programme was terminated, which the registry attributes solely to a business decision.
| Human dosing established | Yes |
|---|---|
| Studied dose range | 10–100 mcg twice daily in phase 2 trials; 10 mcg twice daily in phase 3 |
| Route | Subcutaneous |
| Frequency | Twice daily |
| Duration studied | 35 days to 12 weeks in the gastroparesis trials |
| Evidence level | Clinical Trial Evidence |
| Last reviewed | 2026-11-07 |
Research-reported dosing
Doses as studied, one row per regimen. Different trials used different regimens; they are listed separately rather than averaged.
| Study / context | Population | Dose | Route | Frequency | Duration | Outcome studied | Source |
|---|---|---|---|---|---|---|---|
| Phase 2b, diabetic gastroparesis (NCT02357420)Clinical trial · Randomized, placebo-controlled phase 2b trial | Adults with diabetes and moderate to severe gastroparesis symptoms (n=393) | 10, 30 or 100 mcg | Subcutaneous | Twice daily | 12 weeks, after a 2-week placebo run-in | Core symptoms and composite score fell versus placebo at all doses; gastric emptying faster; vomiting frequency not significantly different from placebo; worse glucose control in 14.5% | Efficacy and Safety of Relamorelin in Diabetics With Symptoms of Gastroparesis: A Randomized, Placebo-Controlled Study. Gastroenterology. 2017. |
| Phase 3, diabetic gastroparesis — terminated (NCT03285308)Clinical trial · Phase 3 randomized, placebo-controlled trial, terminated | Adults with diabetic gastroparesis (n=336) | 10 mcg | Subcutaneous | Twice daily | Up to 12 weeks, after a 2-week placebo run-in | Terminated; the registry reason is that the relamorelin programme was being terminated solely based on a business decision. Results are posted on ClinicalTrials.gov and not summarised here | NCT03285308 — A Safety and Efficacy Study of Relamorelin in Diabetic Gastroparesis 01 |
| Phase 2, diabetic gastroparesis (NCT01571297)Clinical trial · Phase 2 double-blind, placebo-controlled trial | Adults with diabetic gastroparesis (n=204) | Various doses and regimens from 10 to 100 mcg | Subcutaneous | Per trial protocol | 35 days | Gastric emptying time (primary outcome); results not posted on ClinicalTrials.gov | NCT01571297 — Phase 2 Study to Evaluate Safety & Efficacy of RM-131 Administered to Patients With Diabetic Gastroparesis |
| MOVE-PD — constipation in Parkinson's diseaseClinical trial · Randomized, double-blind, placebo-controlled trial | People with Parkinson's disease and chronic constipation (18 of an intended 56 completed) | Not stated in the indexed abstract | Not stated in the indexed abstract | Not stated in the indexed abstract | Not stated in the indexed abstract | Recruitment goals were not met, so no benefit could be shown | A randomized trial of relamorelin for constipation in Parkinson's disease (MOVE-PD): Trial results and lessons learned. Parkinsonism Relat Disord. 2017. |
Where sources disagree
- The phase 3 gastroparesis programme was terminated. ClinicalTrials.gov gives the reason as a business decision; the registry does not describe it as a safety decision.
- Relamorelin is a ghrelin agonist studied for gut motility. Its microgram doses come from gastroparesis trials and say nothing about its use for growth hormone or appetite.
- Dose-related worsening of blood sugar control was reported in the phase 2b trial, and some participants needed changes to their diabetes medicines.
Handling & administration
- Timing Notes
- Investigational for diabetic gastroparesis and GI motility disorders
Sequence & molecular data
| Molecular formula | C43H50N8O5S |
|---|---|
| Molecular weight | 790.97 g/mol |
| CAS number | 661472-41-9 |
| Half-life | Not firmly established in public sources; studied as short-acting sc peptide |
| Appearance | Lyophilized powder or solution (investigational sc) |
| Formulation | Lyophilized Powder |
| PubChem CID | 44251769 |
| ChEMBL | CHEMBL4297525 |
| DrugBank | DB12678 |
Identifiers link to the public PubChem, FDA Substance Registration (UNII), ChEMBL and DrugBank records for the same entity.
Science
Mechanism of Action
Relamorelin is a synthetic pentapeptide agonist at growth hormone secretagogue receptor 1a, developed principally for its gastrointestinal rather than endocrine activity. Ghrelin receptors are expressed on enteric neurons, and their activation accelerates gastric emptying and increases antral contractility. Relamorelin was engineered for greater potency and metabolic stability than native ghrelin and has been studied in diabetic gastroparesis, where delayed gastric emptying underlies the symptoms. It raises growth hormone as a class effect, but that is incidental to its intended use. It is investigational and not approved.
Origin
Synthetic ghrelin-mimetic pentapeptide.
Targets
Studies
- A randomized trial of relamorelin for constipation in Parkinson's disease (MOVE-PD): Trial results and lessons learned
- Efficacy and Safety of Relamorelin in Diabetics With Symptoms of Gastroparesis: A Randomized, Placebo-Controlled Study
- Relamorelin in Gastroparesis and Diabetic Gastroparesis: A Meta-Analysis on Its Efficacy and Safety
- Pharmacological Approaches to Diabetic Gastroparesis: A systematic review of randomised clinical trials
- Relamorelin for the treatment of gastrointestinal motility disorders
Research statistics
34 PubMed publications · 29.4% human clinical research · 13 registered trials
Counts of published research through 2026-11-01, not evidence that it works. Publications by year, study types and trials · How publications are counted
Regulatory & research status
Relamorelin has been studied under an Investigational New Drug application. It is not approved for marketing.
| FDA status | Investigational New Drug (IND) |
|---|---|
| Availability | Research-Only |
| WADA (sport) | Banned in Sport |
| Library classification | Clinical Trial |
How FDA approval, compounding and research-only status differ
Benefits
Relamorelin side effects
The effects below are those reported in Relamorelin clinical trials; long-term safety data may still be limited.
Side Effects
- Hyperglycemia
- Hunger
- GI effects
Storage & stability
This compound is not supplied as a powder to be mixed, so the freeze-dried powder and reconstitution handling described for research peptides does not apply. Storage conditions are product-specific: follow the label or packaging of the product itself.
Relamorelin: frequently asked questions
What is Relamorelin?
Investigational pentapeptide ghrelin receptor agonist developed principally for its gastrointestinal rather than endocrine effects. Ghrelin receptors on enteric neurons accelerate gastric emptying when activated, and relamorelin has been studied mainly in diabetic gastroparesis, where delayed emptying drives the symptoms. Clinical development has been mixed and it is not FDA-approved for any indication.
How does Relamorelin work?
Relamorelin is a synthetic pentapeptide agonist at growth hormone secretagogue receptor 1a, developed principally for its gastrointestinal rather than endocrine activity. Ghrelin receptors are expressed on enteric neurons, and their activation accelerates gastric emptying and increases antral contractility.
Is Relamorelin FDA approved?
No. Relamorelin is investigational: it is in clinical development and has not been approved by the FDA for any indication. Investigational status means trials are ongoing or complete but regulatory review has not resulted in approval, and efficacy and safety are still being established.
What is the half-life of Relamorelin?
Reported half-life for Relamorelin is Not firmly established in public sources; studied as short-acting sc peptide. Half-life describes how long the compound persists in circulation, not how long any effect lasts, and published figures vary with route of administration, formulation and the population studied.
Is Relamorelin banned in sport?
Relamorelin is recorded here as prohibited in sport. Athletes subject to anti-doping rules should check the current WADA Prohibited List directly, since it is revised annually and classifications change.
What peptides are similar to Relamorelin?
Compounds most often compared with Relamorelin include MK-677, Macimorelin, Anamorelin and Tabimorelin. They are grouped by shared mechanism or research area rather than by equivalence, and their regulatory status and evidence base differ.
References
- WADA Prohibited List 2026External reference
- A randomized trial of relamorelin for constipation in Parkinson's disease (MOVE-PD): Trial results and lessons learned — Parkinsonism Relat Disord, 2017External reference
- Efficacy and Safety of Relamorelin in Diabetics With Symptoms of Gastroparesis: A Randomized, Placebo-Controlled Study — Gastroenterology, 2017External reference
- Relamorelin in Gastroparesis and Diabetic Gastroparesis: A Meta-Analysis on Its Efficacy and Safety — Cureus, 2023External reference
- Pharmacological Approaches to Diabetic Gastroparesis: A systematic review of randomised clinical trials — Sultan Qaboos Univ Med J, 2019External reference
- Relamorelin for the treatment of gastrointestinal motility disorders — Expert Opin Investig Drugs, 2017External reference
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Compiled by Peptide Library Editorial · Reviewed Aug 30, 2026 · Updated Nov 7, 2026 · Version 2
This Relamorelin profile is compiled from published literature (5 cited studies linked above), public regulatory records and chemical registries. It describes what research reports; it is not medical advice, and nothing here is a dosing recommendation for humans. Peptide Library does not sell peptides. Editorial policy · How profiles are compiled · Report an error
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