GHRP-6 — Growth Hormone Releasing Peptide with Appetite Stimulation — Growth Hormone
Synthetic hexapeptide GH secretagogue with potent appetite-stimulating effects via ghrelin receptor activation.
Overview
GHRP-6 (Growth Hormone Releasing Peptide-6) is one of the earliest synthetic growth hormone secretagogues, developed in the 1980s. It is a hexapeptide that activates the GHSR-1a (ghrelin receptor) with high affinity, producing potent GH release and significant appetite stimulation. GHRP-6 is distinguished from other GHRPs primarily by its pronounced orexigenic (appetite-increasing) effect, which can be intense — users frequently report overwhelming hunger within 20-30 minutes of injection. This appetite stimulation makes GHRP-6 popular among individuals seeking weight gain or muscle mass but undesirable for those in caloric deficit. GHRP-6 produces robust GH peaks of 20-50 ng/mL at standard doses. It also elevates cortisol and prolactin more than ipamorelin but similarly to GHRP-2. In clinical studies, GHRP-6 has been combined with GHRH to produce synergistic GH release used in diagnostic testing. Some research also suggests gastroprotective properties, with GHRP-6 protecting gastric mucosa from ethanol-induced injury through nitric oxide and prostaglandin-mediated mechanisms. GHRP-6 has not been approved for clinical use in any country and remains a research peptide.
Indications
- No approved indications
- Investigational: GH deficiency diagnostics (combined with GHRH)
- Unapproved: GH release and appetite stimulation (bodybuilding)
- Investigational: Gastroprotection (preclinical)
Mechanism of Action
GHRP-6 activates the ghrelin receptor with high affinity, triggering robust GH secretion from pituitary somatotrophs
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| GHRP-6 | 100-200 mcg | 2-3 times daily | Standard research dose; intense hunger expected |
| GHRP-6 + Mod GRF 1-29 | 100 mcg + 100 mcg | 2-3 times daily | Synergistic combination for maximum GH release |
Evidence Grade
GRADE C
Safety & Contraindications
- Intense appetite stimulation — can be difficult to control
- Cortisol and prolactin elevation
- Injection site reactions and transient flushing
- Water retention and joint discomfort possible
- Blood glucose fluctuations due to hunger-insulin dynamics
- Not FDA-approved — research peptide only
- May worsen insulin sensitivity with chronic use