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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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 - 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
- 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
- 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
- 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 - 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
- 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
- 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
- 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 - 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.
- 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
- 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
- IUPHAR ligand commentary ↗
iuphar-comments · published 2026-08-27 · retrieved 2026-08-27T11:48:55Z
- IUPHAR interactions for macimorelin ↗
iuphar-interactions · published 2026-08-27 · retrieved 2026-08-27T11:48:55Z
- 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