Modified GRF(1-29) vs Macimorelin

Head-to-head comparison of Modified GRF(1-29) ([D-Ala2, Nle27]-human growth hormone-releasing hormone (1-29) amide) and Macimorelin (Macimorelin acetate (AEZS-130)) — benefits, dosing, side effects, research data, and where to buy.

Research Score

PropertyModified GRF(1-29)Macimorelin
CategoryGrowth HormoneGrowth Hormone
Full Name[D-Ala2, Nle27]-human growth hormone-releasing hormone (1-29) amideMacimorelin acetate (AEZS-130)
Molecular WeightN/AN/A
Half-Life10-30 minutesabout 4-6 hours
Amino Acids29N/A
Typical Dose50-300 mcg0.5 mg/kg single oral dose
RouteSubcutaneousOral
Purity≥98%≥98%
Studies Count150120
Research StatusInvestigationalClinical

Modified GRF(1-29) Benefits

  • enhanced GH release
  • greater peptide stability
  • IGF-1 support research
  • longer receptor engagement

Macimorelin Benefits

  • diagnostic GH stimulation
  • single oral dose
  • rapid measurable GH response
  • high clinical utility

Modified GRF(1-29) Dosing

50-100 mcg SC for acute GH-response studies|100-300 mcg SC in monitored research protocols|repeat dosing in short investigative cycles with GH/IGF-1 tracking

Macimorelin Dosing

0.5 mg/kg orally as a single dose|fasted testing conditions|serial GH sampling after administration

Modified GRF(1-29) Side Effects

  • headache
  • water retention
  • injection-site irritation

Macimorelin Side Effects

  • dysgeusia or taste disturbance
  • nausea
  • headache

Research Overview

Modified GRF(1-29)

Modified GRF(1-29) has been studied as a practical GHRH analog for boosting GH release while improving peptide stability versus the native fragment. It is a standard reference compound in experimental work on growth hormone pulsatility and analog design.

Macimorelin

Macimorelin has been validated in clinical testing as an oral alternative to injectable GH stimulation tests. Its short-term use makes it a useful translational tool for evaluating pituitary GH reserve.

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Common Stacking Partners

Modified GRF(1-29) stacks with:

L-arginineL-ornithineglycine

Macimorelin stacks with:

Pituitary testingEndocrine workup
ghrh-analogsynthetic-peptidegrowth-hormoneresearch-compounddiagnosticghrelin-mimeticgh-stimulation-test