What Is GHRH (Growth Hormone Releasing Hormone)?
Growth hormone-releasing hormone, abbreviated GHRH, is a hypothalamic peptide that regulates secretion of growth hormone from somatotroph cells in the anterior pituitary. The hormone was isolated and characterized in the early 1980s after investigators identified a hypothalamic factor capable of stimulating pituitary GH release. This work established GHRH as the principal positive hypothalamic regulator of the GH axis, complementing the inhibitory action of somatostatin. The principal human form, often designated hGHRH(1-44), contains 44 amino acids. Its biologic activity is concentrated in the N-terminal region: the first 29 amino acids retain most of the activity needed for receptor binding and stimulation of GH release, whereas the C-terminal region contributes to molecular properties and activity in the native peptide.
Endogenous GHRH is secreted by hypothalamic neurons in a pulsatile, circadian-regulated pattern. These pulses stimulate corresponding GH pulses from the pituitary, particularly during early nocturnal slow-wave sleep. GHRH has an exceptionally short circulating half-life, commonly estimated at approximately 2-4 minutes, because it is rapidly degraded by peptidases including dipeptidyl peptidase-IV (DPP-IV). This instability prompted development of research analogs. Sermorelin is a synthetic version of the active 1-29 fragment. Modified GRF(1-29), commonly called Mod GRF or CJC-1295 without DAC, incorporates substitutions at positions 2, 8, 15, and 27 to improve stability while retaining a relatively short action. CJC-1295 with DAC contains a drug-affinity complex that markedly prolongs exposure, with pharmacokinetic effects lasting days rather than minutes or hours. These compounds illustrate an important distinction between physiological and pharmacological GH stimulation: short-acting GHRH analogs can reinforce discrete GH pulses, whereas long-acting analogs may produce more sustained stimulation and a less natural secretory pattern.
Quick Reference
Member reference tables summarize the compound's research parameters.
Research Indications
Research Protocols
As reported in cited literature and research-community logs (see Research Citations below), not a personal dosing recommendation.
This member section describes parameters reported in the research literature.
Peptide Interactions
This member section summarizes reported compound interactions and evidence limitations.
Reported Research Time Points
This member section summarizes reported research time points.
Safety Notes
Included for harm-reduction awareness only, in the event this compound is encountered outside its labeled research use. Inclusion here does not imply RUO Codes endorses, recommends, or instructs human use.
This member section discusses research safety considerations and uncertainties.
Quality Indicators
Research Citations
- Effects of a Growth Hormone-Releasing Factor in Patients with HIV
Falutz, J., Allas, S., Blot, K., et al., 2007, New England Journal of Medicine - Effect of Tesamorelin on Visceral Fat and Liver Fat in HIV-Infected Patients With Abdominal Adiposity: A Randomized Clinical Trial
Stanley, T. L., Feldpausch, M. N., Oh, J., et al., 2014, JAMA - Tesamorelin for the Treatment of Non-Alcoholic Fatty Liver Disease in People With HIV: A Randomised, Double-Blind, Multicentre Trial
Stanley, T. L., Fourman, L. T., Feldpausch, M. N., et al., 2019, The Lancet HIV - Long-Term Safety and Effects of Tesamorelin, a Growth Hormone-Releasing Factor Analogue, in HIV-Infected Patients With Abdominal Fat Accumulation
Falutz, J., Allas, S., Mamputu, J. C., et al., 2010, Journal of Clinical Endocrinology and Metabolism