What is Macrilen™?
Macrilen™ (macimorelin) for oral solution requires fewer blood draws than other stimulation tests and eliminates the need for infusion in appropriate patients. With Macrilen™, you can test quickly and efficiently if there is a suspicion of AGHD.1
What is Macrilen™?
Macrilen™ (macimorelin) for oral solution requires fewer blood draws than other stimulation tests and eliminates the need for infusion in appropriate patients. With Macrilen™, you can test quickly and efficiently if there is a suspicion of AGHD.1
Macrilen™ is a prescription test that comes in powder form and is mixed with water to form a solution that patients drink in your office.1
Short test time1
Short test time1
- Only 1.5 hours
- Draw blood samples at 30, 45, 60, and 90 minutes
Routine supervision
Routine supervision
Supervise as the patient drinks the Macrilen™ solution, and observe the patient afterward per routine.1
Supervise as the patient drinks the Macrilen™ solution, and observe the patient afterward per routine.1
Attributes of testing with Macrilen™1
Route of administration
Oral
Number of blood draws
4
Test time for patient
1.5 hours
Required supervision
Routinea
Contraindications
None
aObserve the patient being tested per routine for the duration of the test.
How does Macrilen™ work?
Macrilen™ is an oral ghrelin agonist that stimulates the production of GH in the pituitary gland.1,2
- Ghrelin is a peptide hormone known to cause the release of GH2,3
- Macrilen™ mimics endogenous ghrelin and binds to the GH secretagogue receptor 1a (GHS-R1a). This activates the receptors in the hypothalamus and pituitary gland to stimulate GH release into the circulatory system1,3

Macrilen™ is an oral ghrelin agonist

that binds to GHS-R1a on pituitary and hypothalamic cells

to stimulate GH secretion into the bloodstream.
Getting started
Want to order Macrilen™ for your office? Learn how to start your order and verify patient eligibility.
Macrilen™ vs. the ITT
Discover the data that supports the safety and accuracy of Macrilen™.
Questions about Macrilen™? We’re here to help.
Selected Important Safety Information for Macrilen™
Warnings and Precautions
- QT Prolongation: Macrilen™ causes an increase of about 11 msec in the corrected QT (QTc) interval. QT prolongation can lead to development of torsade de pointes-type ventricular tachycardia with the risk increasing as the degree of prolongation increases. The concomitant use of Macrilen™ with drugs that are known to prolong the QT interval should be avoided
Indication and Limitation of Use
Macrilen™ (macimorelin) 60 mg for oral solution is indicated for the diagnosis of adult growth hormone deficiency (AGHD).
- The safety and diagnostic performance of Macrilen™ have not been established for subjects with a body mass index (BMI) >40 kg/m2
Important Safety Information
Warnings and Precautions
- QT Prolongation: Macrilen™ causes an increase of about 11 msec in the corrected QT (QTc) interval. QT prolongation can lead to development of torsade de pointes-type ventricular tachycardia with the risk increasing as the degree of prolongation increases. The concomitant use of Macrilen™ with drugs that are known to prolong the QT interval should be avoided
- Potential for False Positive Test Results with Use of Strong CYP3A4 Inducers: Concomitant use of strong CYP3A4 inducers with Macrilen™ can decrease macimorelin plasma levels significantly and thereby lead to a false positive result. Strong CYP3A4 inducers should be discontinued and enough time should be given to allow washout of CYP3A4 inducers prior to test administration
- Potential for False Negative Test Results in Recent Onset Hypothalamic Disease: Adult growth hormone (GH) deficiency caused by a hypothalamic lesion may not be detected early in the disease process. Macimorelin acts downstream from the hypothalamus and macimorelin stimulated release of stored GH reserves from the anterior pituitary could produce a false negative result early when the lesion involves the hypothalamus. Repeat testing may be warranted in this situation
Adverse Reactions
- The most common adverse reactions are dysgeusia, dizziness, headache, fatigue, nausea, hunger, diarrhea, upper respiratory tract infection, feeling hot, hyperhidrosis, nasopharyngitis, and sinus bradycardia
Please click here for Macrilen™ Prescribing Information.
References:
- Macrilen [prescribing information]. Plainsboro, NJ: Novo Nordisk Inc; 2021.
- Garcia, JM, Swerdloff R, Wang C, et al. Macimorelin (AEZS-130)-stimulated growth hormone (HG) test: validation of a novel oral stimulation test for the diagnosis of adult GH deficiency. J Clin Endocrinol Metab. 2013;98(6):2422-2429.
- Agarwal V, Garcia JM. The macimorelin-stimulated growth hormone test for adult growth hormone deficiency diagnosis. Expert Rev Mol Diagn. 2014;14(6):647-654.