GHRP-1
One of the original synthetic growth hormone-releasing peptides, a ghrelin-receptor agonist that provokes GH release. It was largely superseded by GHRP-2 and GHRP-6 and has only limited early human data.
01 Overview
GHRP-1 is a synthetic hexapeptide from the first generation of growth hormone-releasing peptides developed from met-enkephalin derivatives. Like its relatives, it activates the ghrelin/GHSR-1a receptor to evoke pituitary GH release, and was used in early GH-secretagogue research.
It was largely eclipsed by the better-studied GHRP-2 and GHRP-6 and never reached clinical approval. Human data are sparse and mostly from acute GH-provocation studies, so its research base is thin and it remains a research peptide.
02 Mechanism
Agonist at the ghrelin/GHSR-1a receptor, stimulating a pulse of endogenous GH from the pituitary.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Anecdotal (research) | 100 mcg | SubQ | Typical self-reported research dose; no validated human protocol. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Provokes GH releaseStimulates a pulse of endogenous GH via the ghrelin receptor. | acute GH pulse | Preclinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Transient cortisol/prolactin riseGHRP-class peptides can transiently raise cortisol and prolactin. | Mild | Common | Preclinical | |
| Injection-site reactionsLocal irritation at the injection site. | Mild | Uncommon | Anecdotal |