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Prescription medicine

Macimorelin Brand names: Macrilen

Macimorelin (Macrilen) is a prescription medicine with an FDA approval on record since 2017. No generic is listed in FDA's NDC Directory.

  • No generic listed

Check it at the source: the macimorelin FDA label on DailyMed (effective February 18, 2026, Aeterna Zentaris GmbH); the NDA 205598 record on Drugs@FDA; every macimorelin label on DailyMed.

Highlights of the record

FDA label of February 18, 2026; NDC Directory, Drugs@FDA and Orange Book, October 8, 2026

Used for

From the label: indications and usage

MACRILEN is indicated for the diagnosis of adult growth hormone deficiency (AGHD).

Forms and strengths

  • 60 mg
  • 60 mg/181

Granule for solution.

On the market

Earliest approval on file
December 20, 2017 Macrilen, Aeterna Zentaris; Drugs@FDA’s file, where older or withdrawn approvals can be missing
Generic approvals
No generic approved
Labelers listed (NDC)
2 of which 0 under generic applications, 2 under brand applications, repackagers included
Last listed patent
April 12, 2028 Macrilen for solution; not a generic launch date

Supply and safety

Pharmacy cost (NADAC)
Not in the survey
Shortage (FDA)
No current entry
Recalls by its makers (FDA)
No recall recorded
FAERS reports
5 through July 30, 2026

What is macimorelin used for?

From the label: indications and usage

MACRILEN is indicated for the diagnosis of adult growth hormone deficiency (AGHD). MACRILEN is a growth hormone (GH) secretagogue receptor agonist indicated for the diagnosis of adult growth hormone deficiency ( 1 ). Limitations of Use: The safety and diagnostic performance has not been established for subjects with BMI > 40kg/m 2 ( 1 ). Limitations of Use The safety and diagnostic performance of MACRILEN have not been established for subjects with a body mass index (BMI) > 40 kg/m 2 .

FDA pharmacologic class: Growth Hormone Secretagogue Receptor Agonist.

Source: FDA drug label (Macrilen), Aeterna Zentaris GmbH, effective February 18, 2026 (SPL set aeb30f1a-4815-47ae-a2cb-b6b4e26372e1), via openFDA; the full label on DailyMed

Is there a generic for macimorelin (Macrilen)?

No generic macimorelin is approved (Drugs@FDA, October 8, 2026).

The Orange Book lists 1 patent for Macrilen for solution, the last expiring on April 12, 2028. A patent or exclusivity date is not the date a generic goes on sale: court cases and settlements move it either way.

  • 2017 earliest approval on file
  • 2028 last listed patent

Source: Drugs@FDA, FDA NDC Directory and the Orange Book (openFDA bulk files, October 8, 2026)

What does the macimorelin label say about other medicines?

The macimorelin label names 26 other medicines in its interaction, contraindication or warning sections. The sentences are the labels' own; a label lists what its studies and reports found, not every interaction.

Medicine namedSectionWhat the label says
Amiodaronedrug interactions… ziprasidone), antibiotics (e.g., moxifloxacin), Class 1A (e.g., quinidine, procainamide) and Class III (e.g., amiodarone, sotalol) antiarrhythmic medications or any other medications known to prolong the QT interval) may lead to development of torsade de pointes-type ventricular tachycardia.
Armodafinildrug interactionsCytochrome P450 (CYP) 3A4 Inducers Co-administration of a strong CYP3A4 inducer with MACRILEN (e.g., carbamazepine, enzalutamide, mitotane, phenytoin, rifampin, St. John's wort, bosentan, efavirenz, etravirine, modafinil, armodafinil, rufinamide) may reduce the plasma macimorelin concentrations and may lead to false …
Aspirindrug interactionsDrugs that directly affect the pituitary secretion of growth hormone (such as somatostatin, insulin, glucocorticoids, and cyclooxygenase inhibitors such as aspirin or indomethacin).
Atropinedrug interactionsDrugs that may blunt the growth hormone response to MACRILEN (such as muscarinic antagonists: atropine, anti-thyroid medication: propylthiouracil, and growth hormone products).
Bosentandrug interactionsCytochrome P450 (CYP) 3A4 Inducers Co-administration of a strong CYP3A4 inducer with MACRILEN (e.g., carbamazepine, enzalutamide, mitotane, phenytoin, rifampin, St. John's wort, bosentan, efavirenz, etravirine, modafinil, armodafinil, rufinamide) may reduce the plasma macimorelin concentrations and may lead to false …
Carbamazepinedrug interactionsCytochrome P450 (CYP) 3A4 Inducers Co-administration of a strong CYP3A4 inducer with MACRILEN (e.g., carbamazepine, enzalutamide, mitotane, phenytoin, rifampin, St. John's wort, bosentan, efavirenz, etravirine, modafinil, armodafinil, rufinamide) may reduce the plasma macimorelin concentrations and may lead to false …
Chlorpromazinedrug interactionsDRUG INTERACTIONS 7.1 Drugs that Prolong QT Interval Co-administration of MACRILEN with drugs that prolong the QT interval (such as antipsychotic medications (e.g., chlorpromazine, haloperidol, thioridazine, ziprasidone), antibiotics (e.g., moxifloxacin), Class 1A (e.g., quinidine, procainamide) and Class III (e.g. …
Clonidinedrug interactionsDrugs that may transiently elevate growth hormone concentrations (such as clonidine, levodopa, and insulin).
Efavirenzdrug interactionsCytochrome P450 (CYP) 3A4 Inducers Co-administration of a strong CYP3A4 inducer with MACRILEN (e.g., carbamazepine, enzalutamide, mitotane, phenytoin, rifampin, St. John's wort, bosentan, efavirenz, etravirine, modafinil, armodafinil, rufinamide) may reduce the plasma macimorelin concentrations and may lead to false …
Enzalutamidedrug interactionsCytochrome P450 (CYP) 3A4 Inducers Co-administration of a strong CYP3A4 inducer with MACRILEN (e.g., carbamazepine, enzalutamide, mitotane, phenytoin, rifampin, St. John's wort, bosentan, efavirenz, etravirine, modafinil, armodafinil, rufinamide) may reduce the plasma macimorelin concentrations and may lead to false …
Etravirinedrug interactionsCytochrome P450 (CYP) 3A4 Inducers Co-administration of a strong CYP3A4 inducer with MACRILEN (e.g., carbamazepine, enzalutamide, mitotane, phenytoin, rifampin, St. John's wort, bosentan, efavirenz, etravirine, modafinil, armodafinil, rufinamide) may reduce the plasma macimorelin concentrations and may lead to false …
Haloperidoldrug interactionsDRUG INTERACTIONS 7.1 Drugs that Prolong QT Interval Co-administration of MACRILEN with drugs that prolong the QT interval (such as antipsychotic medications (e.g., chlorpromazine, haloperidol, thioridazine, ziprasidone), antibiotics (e.g., moxifloxacin), Class 1A (e.g., quinidine, procainamide) and Class III (e.g. …
Indomethacindrug interactionsDrugs that directly affect the pituitary secretion of growth hormone (such as somatostatin, insulin, glucocorticoids, and cyclooxygenase inhibitors such as aspirin or indomethacin).
Levodopadrug interactionsDrugs that may transiently elevate growth hormone concentrations (such as clonidine, levodopa, and insulin).

Every other medicine the macimorelin label names

Medicine namedSectionWhat the label says
Mitotanedrug interactionsCytochrome P450 (CYP) 3A4 Inducers Co-administration of a strong CYP3A4 inducer with MACRILEN (e.g., carbamazepine, enzalutamide, mitotane, phenytoin, rifampin, St. …
Modafinildrug interactions… phenytoin, rifampin, St. John's wort, bosentan, efavirenz, etravirine, modafinil, armodafinil, rufinamide) may reduce the plasma macimorelin concentrations and may lead to false positive test results.
Moxifloxacindrug interactions… chlorpromazine, haloperidol, thioridazine, ziprasidone), antibiotics (e.g., moxifloxacin), Class 1A (e.g., quinidine, procainamide) and Class III (e.g., amiodarone, sotalol) antiarrhythmic …
Phenytoindrug interactionsCytochrome P450 (CYP) 3A4 Inducers Co-administration of a strong CYP3A4 inducer with MACRILEN (e.g., carbamazepine, enzalutamide, mitotane, phenytoin, rifampin, St. …
Procainamidedrug interactions… ziprasidone), antibiotics (e.g., moxifloxacin), Class 1A (e.g., quinidine, procainamide) and Class III (e.g., amiodarone, sotalol) antiarrhythmic medications or any other medications known to prolong …
Propylthiouracildrug interactionsDrugs that may blunt the growth hormone response to MACRILEN (such as muscarinic antagonists: atropine, anti-thyroid medication: propylthiouracil, and growth hormone products).
Quinidinedrug interactions… thioridazine, ziprasidone), antibiotics (e.g., moxifloxacin), Class 1A (e.g., quinidine, procainamide) and Class III (e.g., amiodarone, sotalol) antiarrhythmic medications or any other medications …
Rifampindrug interactionsCytochrome P450 (CYP) 3A4 Inducers Co-administration of a strong CYP3A4 inducer with MACRILEN (e.g., carbamazepine, enzalutamide, mitotane, phenytoin, rifampin, St. …
Rufinamidedrug interactions… John's wort, bosentan, efavirenz, etravirine, modafinil, armodafinil, rufinamide) may reduce the plasma macimorelin concentrations and may lead to false positive test results.
Sotaloldrug interactions… 1A (e.g., quinidine, procainamide) and Class III (e.g., amiodarone, sotalol) antiarrhythmic medications or any other medications known to prolong the QT interval) may lead to development of torsade …
Thioridazinedrug interactions… (such as antipsychotic medications (e.g., chlorpromazine, haloperidol, thioridazine, ziprasidone), antibiotics (e.g., moxifloxacin), Class 1A (e.g., quinidine, procainamide) and Class III (e.g. …
Ziprasidonedrug interactions… antipsychotic medications (e.g., chlorpromazine, haloperidol, thioridazine, ziprasidone), antibiotics (e.g., moxifloxacin), Class 1A (e.g., quinidine, procainamide) and Class III (e.g., amiodarone …

Check macimorelin against other medicines

Source: FDA drug label (Macrilen), Aeterna Zentaris GmbH, effective February 18, 2026 (SPL set aeb30f1a-4815-47ae-a2cb-b6b4e26372e1), via openFDA; the full label on DailyMed

What do FAERS reports show for macimorelin?

The FDA Adverse Event Reporting System holds 5 reports that list macimorelin among the medicines taken, through July 30, 2026, each a report of something that happened, not proof the medicine caused it; 0 are coded as a death and 0 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is.

The most reported reactions

  • Bradycardia (named in the label)1
  • Dizziness (named in the label)1
  • Dysgeusia (named in the label)1
  • Fatigue (named in the label)1
  • Feeling Hot (named in the label)1
  • Fluid Retention1
  • Flushing1
  • Nausea (named in the label)1

Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026

What next?

Macimorelin side effects
the label's list beside FAERS reports
Check an interaction
what two or more labels say about each other