Page data last changed: . Registry refreshes and identity assessments are separate from scientific content review.
The 'housekeeper of the gut' — sweeps the small intestine during fasting.
Part of the Metabolic & GLP-1 peptides cluster
Overview
Motilin is a 22-amino-acid gut hormone secreted by endocrine cells of the small intestine. It coordinates the migrating motor complex, the wave of contractions that clears the digestive tract between meals, earning it the nickname the housekeeper of the gut.
Source & context
Biological / chemical source: Endocrine cells of the small intestine
Primary research or clinical context: Endogenous hormone; its receptor inspired 'motilide' prokinetic research
Fasting-state motility
Between meals, motilin levels rise and fall in cycles that trigger the migrating motor complex — sweeping contractions that move residual contents through the small intestine. This distinguishes motilin from hormones that act mainly after eating, and makes it central to gastrointestinal-motility research.
The motilide connection
The motilin receptor is notable because certain macrolide antibiotics act on it as motilin mimetics ('motilides'), an observation that spurred research into prokinetic compounds. Motilin is therefore a recurring reference in discussions of how a single receptor can bridge peptide and small-molecule pharmacology.
Sequence of the selected reference form
Sequence backbone for the reference form: Human motilin(1-22), native free-acid mature peptide. Termini, stereochemistry and modifications are described below.
FVPIFTYGELQRMQEKERNKGQ
Residues plotted ~100° apart around an α-helix — clustering of one color reveals an amphipathic face.
Structure & chemistry
Molecular identity & reference confidence
Source-supported reference
The reviewed human precursor, original human cDNA study and PubChem graph agree on the 22-residue methionine-containing human chain.
- Molecular form
- Human motilin(1-22), native free-acid mature peptide
- Species
- Homo sapiens
- Termini (N / C)
- Free alpha-amino group of L-phenylalanine / Free L-glutamine carboxylic acid (-COOH)
Average reference mass · Molecular identity assessment: 2026-10-05
Reference policy updated: 2026-10-05
- PubChem PUG molecular properties and explicit molecular graph · 2026-10-05
- PubChem PUG stereochemistry and normalized structure identity · 2026-10-05
- Reviewed UniProt molecular sequence and processed-chain annotations · 2026-10-05
- Sequence of an intestinal cDNA encoding human motilin precursor. · 2026-10-05
- Molecular formula
- C120H188N34O35S
- Average reference mass
- ≈ 2,699.1
- Backbone
- Human motilin(1-22), native free-acid mature peptide
- C-terminus
- Free L-glutamine carboxylic acid (-COOH)
- PubChem CID: 16136567
Chemistry values: curated profile, PubChem.
Clinical development snapshot
ClinicalTrials.gov lists 16 registered studies with “Motilin” as an intervention (snapshot 2026-10-01). A registry footprint is not evidence of efficacy or approval.
| NCT | Title | Phase | Status | Updated |
|---|---|---|---|---|
| NCT03024879 | The Effect of Motilin on the Frequency and Amount of Food Intake | Phase 4 | unknown | 2024-07-10 |
| NCT04380233 | Zhizhu Kuanzhong Capsule for Patients With Functional Dyspepsia-Postprandial Distress Syndrome | Not applicable | unknown | 2022-03-04 |
| NCT01262898 | Dose Response of 28 Days of Dosing of GSK962040 in Type I and II Diabetic Male and Female Subjects With Gastro | Phase 2 | completed | 2021-07-15 |
| NCT04008290 | The Effect of Liraglutide on the GIT | Phase 4 | unknown | 2019-07-05 |
| NCT04005781 | Effect of Bitter in Overweight Female Volunteers | Phase 4 | unknown | 2019-07-02 |
| NCT04005768 | Effect of Hydroxychloroquine Sulphate in Healthy Lean Females | Phase 4 | unknown | 2019-07-02 |
Motilin — reconstitution calculator
Enter how much peptide is in the vial and how much diluent (e.g. bacteriostatic water) is added. The tool returns the resulting solution concentration — and, for any amount you type, the volume it corresponds to. This is educational arithmetic, not a dosing recommendation.
Reference form: Human motilin(1-22), native free-acid mature peptideAverage reference mass: 2,699.1 Da
Enter an amount to see the volume it corresponds to.
Educational concentration mathematics only. This tool does not recommend a dose, amount, or protocol, and nothing here is medical advice. Many peptides are not authorized by Health Canada for human use — see our reconstitution and bacteriostatic-water guides for context.
Change log
Dated observations from the data pipeline (registry flags, trial footprints, identifiers) and editorial reviews of this profile.
- ChemistryPubChem formula updated to C120H188N34O35S.
FAQ about Motilin
What is Motilin?+
Motilin is a 22-amino-acid gut hormone secreted by endocrine cells of the small intestine. It coordinates the migrating motor complex, the wave of contractions that clears the digestive tract between meals, earning it the nickname the housekeeper of the gut.
What Canadian product status is recorded for Motilin?+
Canadian product status for Motilin has not been verified in this profile. No verified record here does not mean no authorization exists. Status depends on the product, formulation and use; consult Health Canada's product records.
What is the length of the selected reference form for Motilin?+
The selected reference form (Human motilin(1-22), native free-acid mature peptide) has 22 residues or residue-derived units in its backbone. Other forms in this family may have a different length.
Related peptides
References & further reading
- 1.Poitras et al. (2008). Motilin. Curr Opin Endocrinol Diabetes Obes
- 2.Kitazawa et al. (2026). Motilin in amphibians. Gen Comp Endocrinol
- 3.Itoh (1997). Motilin and clinical application. Peptides
- 4.Kitazawa et al. (2021). Motilin Comparative Study: Structure, Distribution, Receptors, and Gastrointestinal Motility. Front Endocrinol (Lausanne)
- 5.Deloose et al. (2019). Motilin: from gastric motility stimulation to hunger signalling. Nat Rev Endocrinol
- 6.Mori et al. (2023). Physiological functions and potential clinical applications of motilin. Peptides
- 7.Matsumoto et al. (2022). Identification of motilin in Japanese fire bellied newt. Gen Comp Endocrinol
- 8.Singaram et al. (2020). Motilin: a panoply of communications between the gut, brain, and pancreas. Expert Rev Gastroenterol Hepatol
- 9.PubChem — compound summary for Motilin (CID 16136567)
- 10.Wikipedia — Motilin