GHRP-6
Molecular Identifiers
Overview
First-generation GH-releasing peptide with strong ghrelin activity. Causes significant appetite increase. Potent GH release.
GHRP-6 drives potent endogenous GH release via high-affinity GHS-R1a receptor agonism, but with a strong ghrelinergic component and intense appetite increase, a feature that historically tied it to weight-gain and bulking protocols. Higher doses can raise cortisol and prolactin, which limits prolonged use.
GHRP-6 has no regulatory approval from any agency (FDA, EMA, ANVISA). It is typically dispensed by compounding pharmacies as off-label use in 8–12 week protocols, in up to three subcutaneous administrations per day (morning, post-workout, bedtime), often combined with GHRH analogs. It has gradually been replaced by more selective options such as GHRP-2 and ipamorelin. GH secretagogues are banned by WADA at all times.
It is one of the first GH-releasing peptides developed from synthetic hexapeptide libraries in the late 1980s, before ghrelin was identified as the endogenous ligand of GHS-R1a.
Among the GHRPs, GHRP-6 is the most ghrelinergic, with appetite stimulation markedly greater than GHRP-2 or hexarelin and in contrast to the selective profile of ipamorelin (no increase in appetite, cortisol, or prolactin). Compared to GHRH analogs (sermorelin, CJC-1295, tesamorelin) it acts on GHS-R1a rather than the GHRH receptor and is often paired with one of them; oral MK-677 reaches the same receptor with a 24-hour duration and preserves the appetite effect.
His-D-Trp-Ala-Trp-D-Phe-Lys-NH₂ Contains D-amino acids (D-Trp, D-Phe)
Half-life
~15-20 minutes
Administration Route
Subcutaneous
Category
GH Secretagogues
Mechanism of Action
- High-affinity GHS-R1a receptor agonist
- Strong ghrelinergic activity (significant appetite increase)
- Potent GH release
- May elevate cortisol and prolactin at high doses
Dosage Protocol
Data compiled from the literature. This does not constitute medical advice.
| Parameter | Value |
|---|---|
| Dose | 100-300 mcg per injection |
| Frequency | 2-3 times per day |
| Timing | Morning, post-workout and before bedtime |
| Duration | 8-12 weeks |
Reported Side Effects
Adverse effects described in the literature. Severity and frequency vary between individuals.
- Intense appetite increase
- Water retention
- Elevated cortisol
- Lethargy
Product Properties
| Purity | >99% |
| Appearance | White lyophilized powder |
| Solubility | Soluble in water and bacteriostatic water |
| Source | Solid-phase peptide synthesis (SPPS) |
| Storage | Lyophilized: -20°C for up to 2 years, 2-8°C for up to 6 months. Reconstituted: 2-8°C for up to 4 weeks. Protect from light and moisture. Avoid repeated freeze-thaw cycles. |
Presentations & Preparation
Vials of GHRP-6 found in the research market:
Reconstitution
- Diluent: Bacteriostatic water
- Volume: 2 ml per 5 mg vial
- Inject the diluent slowly against the vial wall
- Gently swirl until fully dissolved
- Never shake
Storage
- Lyophilized: Room temperature or refrigerated
- Reconstituted: Refrigerated 2-8°C (up to 30 days)
- Protect from direct light
- Do not freeze after reconstitution
Scientific Studies
Published studies on GHRP-6.
Use of growth-hormone-releasing peptide-6 (GHRP-6) for the prevention of multiple organ failure
Berlanga J, Cibrian D, Guillen I, Freyre F, Alba JS, Lopez-Saura P, Merino N, Aldama A, Quintela AM, Triana ME, Montequin JF, Ajamieh H, Urquiza D, Ahmed N, Guillen G
Effects of growth hormone-releasing peptide-6 on the nocturnal secretion of GH, ACTH and cortisol and on the sleep EEG in man: role of routes of administration
Frieboes RM, Murck H, Antonijevic IA, Steiger A
Growth hormone-releasing effect of oral growth hormone-releasing peptide 6 (GHRP-6) administration in children with short stature
Bellone J, Ghizzoni L, Aimaretti G, Volta C, Boghen MF, Bernasconi S, Ghigo E
Related Peptides
CJC-1295 with DAC
1-2 mg per week · Once per week
CJC-1295 sem DAC
100-200 mcg per injection · 2-3 times daily
GHRP-2
100-300 mcg per injection · 2-3 times per day
Hexarelin
200-300 mcg per injection · 2-3 times per day
Ipamorelin
200-300 mcg per injection · 2-3 times daily
MK-677
10-25 mg per dose · Once daily