Peptide LibraryMacimorelin dosage in published studies and labels
These are the doses used for Macimorelin in FDA labelling and published clinical studies, reported as each source states them, one row per regimen. They describe what was studied or approved for a specific population. They are not a recommendation, and none of them is a dose for any individual.
Research and educational reference only. This is not medical advice, and no figure on this page is a dosing recommendation.
Last checked against primary sources:
Studied regimens and sources
Macimorelin has an FDA-approved human dosage as a single oral diagnostic dose for adult growth hormone deficiency. The MACRILEN label dose is 0.5 mg/kg taken as a solution after fasting for at least 8 hours, with growth hormone measured at 30, 45, 60 and 90 minutes; a peak below 2.8 ng/mL confirms the deficiency. Its safety and efficacy in children have not been established.
| Human dosing established | Yes |
|---|---|
| Studied dose range | 0.5 mg/kg as a single oral dose (diagnostic test) |
| Route | Oral |
| Frequency | Single dose per test |
| Duration studied | One diagnostic test; blood sampled up to 90 minutes |
| Evidence level | FDA Approved |
| Last reviewed | 2026-11-07 |
Research-reported dosing
Doses as studied, one row per regimen. Different trials used different regimens; they are listed separately rather than averaged.
| Study / context | Population | Dose | Route | Frequency | Duration | Outcome studied | Source |
|---|---|---|---|---|---|---|---|
| FDA label — MACRILEN, adult growth hormone deficiencyFDA-approved label · FDA prescribing information | Adults being tested for growth hormone deficiency | 0.5 mg/kg | Oral solution, after fasting for at least 8 hours | Once | Growth hormone sampled at 30, 45, 60 and 90 minutes | Maximally stimulated growth hormone below 2.8 ng/mL confirms adult growth hormone deficiency | MACRILEN (macimorelin) for oral solution — FDA prescribing information (Aeterna Zentaris), DailyMed |
| Pivotal diagnostic trial against the insulin tolerance test (Garcia et al., 2018)Clinical trial · Multicentre open-label randomised crossover trial | Adults with high (n=38), intermediate (n=37) and low (n=39) likelihood of growth hormone deficiency, and matched healthy controls (n=25) | Single oral dose; the amount is not stated in the indexed abstract | Oral | Once, repeated in a crossover with the insulin tolerance test | Single test | At a 2.8 ng/mL cutoff: sensitivity 87%, specificity 96%; reproducibility 97% on retesting (n=33) | Garcia JM et al. Macimorelin as a Diagnostic Test for Adult GH Deficiency. J Clin Endocrinol Metab. 2018. |
| Pilot trial in cancer cachexia (Herodes et al., 2023)Clinical trial · Randomised placebo-controlled pilot trial | Patients with cancer cachexia (10 on macimorelin, 5 on placebo) | 0.5 or 1.0 mg/kg, or placebo | Oral | Daily | 1 week | No related adverse events; body weight and quality of life improved numerically but not significantly against placebo | Herodes M et al. Pilot clinical trial of macimorelin to assess safety and efficacy in patients with cancer cachexia. J Cachexia Sarcopenia Muscle. 2023. |
Where sources disagree
- The only labelled use is a one-time diagnostic test. Daily dosing for cachexia was tested only in a 1-week pilot of 15 patients and is not an approved use.
- The label warns that MACRILEN increases the corrected QT interval by about 11 msec and advises avoiding drugs that prolong QT. It says to stop growth hormone therapy at least one week before the test, stop strong CYP3A4 inducers, and replace other missing pituitary hormones first.
- DailyMed carries two MACRILEN listings with the same dosage: Aeterna Zentaris (cited here) and Novo Nordisk.