Modified GRF(1-29) vs hGHRH(1-40)OH

Head-to-head comparison of Modified GRF(1-29) ([D-Ala2, Nle27]-human growth hormone-releasing hormone (1-29) amide) and hGHRH(1-40)OH (Human growth hormone-releasing factor (1-40) hydroxyl) — benefits, dosing, side effects, research data, and where to buy.

PropertyModified GRF(1-29)hGHRH(1-40)OH
CategoryGrowth HormoneGrowth Hormone
Full Name[D-Ala2, Nle27]-human growth hormone-releasing hormone (1-29) amideHuman growth hormone-releasing factor (1-40) hydroxyl
Molecular WeightN/AN/A
Half-Life10-30 minutes5-20 minutes
Amino Acids2940
Typical Dose50-300 mcg1-2 mcg/kg
RouteSubcutaneousSubcutaneous/IV
Purity≥98%≥98%
Studies Count15085
Research StatusInvestigationalClinical Research

Modified GRF(1-29) Benefits

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

hGHRH(1-40)OH Benefits

  • GH secretion research
  • fragment-activity comparison
  • receptor binding studies
  • axis physiology modeling

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(1-40)OH Dosing

1-2 mcg/kg SC or IV in acute research settings|single-bolus GH stimulation protocols|repeated low-dose administration in comparative studies

Modified GRF(1-29) Side Effects

  • headache
  • water retention
  • injection-site irritation

hGHRH(1-40)OH Side Effects

  • flushing
  • headache
  • lightheadedness

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(1-40)OH

Human GHRF(1-40)OH has been studied to understand how truncation of the native hormone changes biological potency and half-life. It is a common research tool for mapping minimal active sequences within the GHRH family.

Ready to buy?

Find both peptides from our verified, lab-tested vendors with purity certificates and third-party testing.

Common Stacking Partners

Modified GRF(1-29) stacks with:

L-arginineL-ornithineglycine

hGHRH(1-40)OH stacks with:

L-arginineL-ornithineglycine
ghrh-analogsynthetic-peptidegrowth-hormoneresearch-compoundghrhfragmentpituitaryresearch-peptide