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ghrelin agonist

Macimorelin

Published evidence · coverage incomplete
Anatomical contextAnatomy connections are not mapped yet.

No body region is highlighted until this profile has a supported anatomical connection. This does not mean the peptide has no biological effects.

Read published mechanism findings ↓

At a glance

What is it—and why does it matter?

The dosage form is granules for oral solution: 60 mg per pouch reconstituted in 120 mL water to yield 0.5 mg/mL macimorelin. Macimorelin stimulates the ghrelin receptor, consistent with a ghrelin receptor agonist mechanism. Macimorelin stimulation testing is used as a diagnostic approach for adult growth hormone deficiency. In individuals with BMI > 40 kg/m2, MACRILEN lacks established safety and diagnostic performance data.

Sources for this introduction: [1] [2] [3] [4]

This published profile is a reference in progress. Findings retain their source context; missing topics are marked below.

What is it?

A molecule, not a product name.

Identity

The dosage form is granules for oral solution: 60 mg per pouch reconstituted in 120 mL water to yield 0.5 mg/mL macimorelin.

Source records
1
Regulatory records
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    For oral solution: 60 mg white to off-white granules in a pouch for reconstitution in 120 mL of water, resulting in a solution of 0.5 mg/mL of macimorelin.

    These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017 · 3 DOSAGE FORMS AND STRENGTHS

    dailymed:aeb30f1a-4815-47ae-a2cb-b6b4e26372e1:a97cb953722d:a97cb953722d

How does it work?

Target, response, and disposition.

Mechanism

Macimorelin functions as a growth hormone secretagogue, promoting GH secretion.

Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    It is a growth hormone (GH) secretagogue.

    IUPHAR ligand commentary · General comments

    iuphar-comments:9745:9505b1ba8f79:9505b1ba8f79

Mechanism

Macimorelin stimulates the ghrelin receptor, consistent with a ghrelin receptor agonist mechanism.

Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Macimorelin, a ghrelin receptor agonist, is used for diagnosing adult GH deficiency (AGHD).

    Real-world diagnostic performance of the macimorelin stimulation test in the diagnosis of adult growth hormone deficiency. · Abstract

    pubmed:41793495:db90adcac546:db90adcac546

Pharmacokinetics

Food effect: a liquid meal reduces macimorelin exposure, decreasing peak concentration (Cmax) and overall exposure (AUC) by 55% and 49%.

Reported result
Cmax -55%; AUC -49%
Source records
1
Regulatory records
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    A liquid meal decreased the macimorelin Cmaxand AUC by 55% and 49%, respectively.

    These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017 · 12.3 Pharmacokinetics

    dailymed:6034c9b8-5a36-4961-a5dd-11ebf7bdab78:cef1f430acce:cef1f430acce

Pharmacokinetics

Elimination kinetics: after a single 0.5 mg/kg oral dose, macimorelin shows a mean terminal half-life of 4.1 hours in healthy subjects.

Reported result
mean T1/2 4.1 hours
Source records
1
Regulatory records
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Macimorelin was eliminated with a mean terminal half-life (T1/2) of 4.1 hours following administration of a single oral dose of 0.5 mg macimorelin/kg body weight in healthy subjects.

    These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017 · 12.3 Pharmacokinetics

    dailymed:6034c9b8-5a36-4961-a5dd-11ebf7bdab78:cef1f430acce:cef1f430acce

What has been studied?

What the evidence says.

Study findings

Using MACRILEN stimulation testing, a peak (maximally stimulated) serum GH concentration below 2.8 ng/mL across the specified sampling timepoints is interpreted as confirming adult growth hormone deficiency.

Reported result
Cut point: < 2.8 ng/mL
Source records
1
Regulatory records
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Clinical studies have established that a maximally stimulated serum GH level of less than 2.8 ng/mL (i.e., at the 30, 45, 60 and 90 minute timepoints) following MACRILEN administration confirms the presence of adult growth hormone deficiency.

    These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017 · 2.4 Interpretation of MACRILEN Test Results

    dailymed:6034c9b8-5a36-4961-a5dd-11ebf7bdab78:cef1f430acce:cef1f430acce

Study findings

Macimorelin stimulation testing is used as a diagnostic approach for adult growth hormone deficiency.

Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Macimorelin, a ghrelin receptor agonist, is used for diagnosing adult GH deficiency (AGHD).

    Real-world diagnostic performance of the macimorelin stimulation test in the diagnosis of adult growth hormone deficiency. · Abstract

    pubmed:41793495:db90adcac546:db90adcac546

Study findings

Diagnostic interpretation uses a GH peak criterion: a maximally stimulated serum GH < 2.8 ng/mL across the specified post-dose sampling times indicates AGHD.

Reported result
GH < 2.8 ng/mL
Source records
1
Regulatory records
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Clinical studies have established that a maximally stimulated serum GH level of less than 2.8 ng/mL (i.e., at the 30, 45, 60 and 90 minute timepoints) following MACRILEN administration confirms the presence of adult growth hormone deficiency.

    These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017 · 2.4 Interpretation of MACRILEN Test Results

    dailymed:aeb30f1a-4815-47ae-a2cb-b6b4e26372e1:a97cb953722d:a97cb953722d

Studied populations

In pediatric populations, MACRILEN lacks established safety and efficacy.

Source records
1
Regulatory records
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    The safety and efficacy of MACRILEN in pediatric patients have not been established.

    These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017 · 8.4 Pediatric Use

    dailymed:6034c9b8-5a36-4961-a5dd-11ebf7bdab78:cef1f430acce:cef1f430acce

Studied populations

In pediatric patients, MACRILEN lacks established safety and efficacy.

Source records
1
Regulatory records
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    The safety and efficacy of MACRILEN in pediatric patients have not been established.

    These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017 · 8.4 Pediatric Use

    dailymed:aeb30f1a-4815-47ae-a2cb-b6b4e26372e1:a97cb953722d:a97cb953722d

Risks and interactions

Risks, organized for scanning.

Interactions

Drug interaction: strong CYP3A4 induction can reduce macimorelin exposure substantially, potentially producing false positive MACRILEN diagnostic results.

Source records
1
Regulatory records
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Concomitant use of strong CYP3A4 inducers with MACRILEN can decrease macimorelin plasma levels significantly and thereby lead to a false positive result[see Drug Interactions (7.2)].

    These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017 · 5.2 Potential for False Positive Test Results with Use of Strong CYP3A4 Inducers

    dailymed:6034c9b8-5a36-4961-a5dd-11ebf7bdab78:cef1f430acce:cef1f430acce

Interactions

To reduce interaction risk, strong CYP3A4 inducers are to be discontinued before administering macimorelin (MACRILEN).

Source records
2
Independent studies
1
Regulatory records
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Discontinue strong CYP3A4 inducers prior to MACRILEN use[see Warning and Precautions (5.2) and Drug Interactions (7.2)].

    These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017 · 2.2 Important Recommendations Before MACRILEN Use

    dailymed:aeb30f1a-4815-47ae-a2cb-b6b4e26372e1:a97cb953722d:a97cb953722d
  2. supports · Source-backed record
    Target: ghrelin receptor (Human) Action: Agonist

    IUPHAR interactions for macimorelin · Interaction 84737

    iuphar-interactions:9745:41c50aea82a7:41c50aea82a7

Safety findings

Macimorelin administration is associated with QTc prolongation of about 11 milliseconds.

Reported result
about 11 msec increase
Source records
1
Regulatory records
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    MACRILEN causes an increase of about 11 msec in the corrected QT (QTc) interval[see Clinical Pharmacology (12.2)].

    These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017 · 5.1 QT Prolongation

    dailymed:6034c9b8-5a36-4961-a5dd-11ebf7bdab78:cef1f430acce:cef1f430acce

Safety findings

In individuals with BMI > 40 kg/m2, MACRILEN lacks established safety and diagnostic performance data.

Source records
1
Regulatory records
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    The safety and diagnostic performance of MACRILEN have not been established for subjects with a body mass index (BMI) > 40 kg/m2.

    These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017 · Untitled section

    dailymed:aeb30f1a-4815-47ae-a2cb-b6b4e26372e1:a97cb953722d:a97cb953722d

Products and regulatory status

Same ingredient. Different records.

Regulatory status

Macimorelin is indicated as a diagnostic agent for adult growth hormone deficiency (AGHD).

Source records
2
Regulatory records
2

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    MACRILEN is indicated for the diagnosis of adult growth hormone deficiency (AGHD).

    These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017 · 1 INDICATIONS AND USAGE

    dailymed:6034c9b8-5a36-4961-a5dd-11ebf7bdab78:cef1f430acce:cef1f430acce
  2. supports · Source-backed record
    MACRILEN is indicated for the diagnosis of adult growth hormone deficiency (AGHD).

    These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017 · 1 INDICATIONS AND USAGE

    dailymed:aeb30f1a-4815-47ae-a2cb-b6b4e26372e1:a97cb953722d:a97cb953722d

Administration context

The practical clinical context.

Administration

The dosage form is an oral-solution preparation: a 60 mg pouch of macimorelin granules is reconstituted with 120 mL water to yield 0.5 mg/mL.

Source records
1
Regulatory records
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    For oral solution: 60 mg white to off-white granules in a pouch for reconstitution in 120 mL of water, resulting in a solution of 0.5 mg/mL of macimorelin.

    These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017 · 3 DOSAGE FORMS AND STRENGTHS

    dailymed:6034c9b8-5a36-4961-a5dd-11ebf7bdab78:cef1f430acce:cef1f430acce

Administration

The macimorelin GH stimulation test specifies serial venous sampling for GH at 30, 45, 60, and 90 minutes post-dose.

Source records
1
Regulatory records
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Draw venous blood samples for GH determination at30 minutes, 45 minutes, 60 minutes and 90 minutesafter administration of MACRILEN.

    These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017 · 2.3 Directions for Preparation and Administration

    dailymed:aeb30f1a-4815-47ae-a2cb-b6b4e26372e1:a97cb953722d:a97cb953722d

Dose records

Recommended dosing for the macimorelin diagnostic test is a single 0.5 mg/kg oral dose, administered as a reconstituted solution under fasting conditions (≥8 hours).

Source records
2
Regulatory records
2

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    The recommended dose is a single oral dose of 0.5 mg/kg of macimorelin. The dose is administered as a reconstituted solution[see Dosage and Administration (2.3)]in patients fasted for at least 8 hours.

    These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017 · 2.1 Recommended Dose

    dailymed:6034c9b8-5a36-4961-a5dd-11ebf7bdab78:cef1f430acce:cef1f430acce
  2. supports · Source-backed record
    The recommended dose is a single oral dose of 0.5 mg/kg of macimorelin. The dose is administered as a reconstituted solution[see Dosage and Administration (2.3)]in patients fasted for at least 8 hours.

    These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017 · 2.1 Recommended Dose

    dailymed:aeb30f1a-4815-47ae-a2cb-b6b4e26372e1:a97cb953722d:a97cb953722d

Research status + gaps

What still needs better answers?

  • No publishable claim yet for: contraindication
  • 42 compiled claim(s) withheld by automated assurance: assurance_score_below_0.58 (23), assurance_score_below_0.72 (18), current_regulatory_source_required (12), extraction_ambiguity (25), extraction_confidence_not_high (10), high_risk_requires_regulatory_or_two_independent_sources (18), no_direct_support (40)

These are the limits of this profile, not an exhaustive list of scientific uncertainties.

References + discovery

Open the records yourself.

  1. These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017

    dailymed · published 2021-01-30 · retrieved 2026-09-04T22:09:49Z

  2. These highlights do not include all the information needed to use MACRILEN safely and effectively. See full prescribing information for MACRILEN.MACRILEN (macimorelin) for oral solutionInitial U.S. Approval: 2017

    dailymed · published 2026-02-18 · retrieved 2026-09-04T22:09:50Z

  3. IUPHAR ligand commentary

    iuphar-comments · published 2026-08-27 · retrieved 2026-08-27T11:48:55Z

  4. IUPHAR interactions for macimorelin

    iuphar-interactions · published 2026-08-27 · retrieved 2026-08-27T11:48:55Z

  5. Real-world diagnostic performance of the macimorelin stimulation test in the diagnosis of adult growth hormone deficiency.

    pubmed · published 2026-03-07 · retrieved 2026-08-27T11:48:55Z

Publication history and provenance

Version 3 · Automated assessment · 2026-09-04T22:09:50Z

b23b2e5a7580eaa067d6dc73b5d61aed64f65ef8692228fb8dbc654630fcda3b