Modified GRF(1-29) vs hGHRH(1-37)OH

Head-to-head comparison of Modified GRF(1-29) ([D-Ala2, Nle27]-human growth hormone-releasing hormone (1-29) amide) and hGHRH(1-37)OH (Human growth hormone-releasing factor (1-37) hydroxyl) — benefits, dosing, side effects, research data, and where to buy.

PropertyModified GRF(1-29)hGHRH(1-37)OH
CategoryGrowth HormoneGrowth Hormone
Full Name[D-Ala2, Nle27]-human growth hormone-releasing hormone (1-29) amideHuman growth hormone-releasing factor (1-37) hydroxyl
Molecular WeightN/AN/A
Half-Life10-30 minutes5-20 minutes
Amino Acids2937
Typical Dose50-300 mcg1-2 mcg/kg
RouteSubcutaneousSubcutaneous/IV
Purity≥98%≥98%
Studies Count15060
Research StatusInvestigationalClinical Research

Modified GRF(1-29) Benefits

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

hGHRH(1-37)OH Benefits

  • GH release studies
  • minimal-sequence mapping
  • receptor pharmacology
  • peptide stability research

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

hGHRH(1-37)OH Dosing

1-2 mcg/kg SC or IV bolus|acute stimulation with serial GH assays|short-course research administration with biomarker monitoring

Modified GRF(1-29) Side Effects

  • headache
  • water retention
  • injection-site irritation

hGHRH(1-37)OH Side Effects

  • flushing
  • headache
  • transient fatigue

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.

hGHRH(1-37)OH

Human GHRF(1-37)OH has appeared in studies examining how loss of C-terminal residues affects biological activity at the GHRH receptor. It is often used alongside other fragments to define structure-activity relationships within the GHRH family.

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Common Stacking Partners

Modified GRF(1-29) stacks with:

L-arginineL-ornithineglycine

hGHRH(1-37)OH stacks with:

L-arginineL-lysineglycine
ghrh-analogsynthetic-peptidegrowth-hormoneresearch-compoundghrhfragmentstructure-activityendocrinology