GHRP-6
Potent, Muscle Building
In short
- A hexapeptide ghrelin receptor agonist and one of the earliest growth hormone secretagogues developed.
- Unlike ipamorelin it is non-selective: it also raises cortisol and prolactin, and produces pronounced hunger.
- The appetite effect is the most reliable and noticeable thing it does, and is often the reason people stop.
- Real human research exists from the 1980s-90s, largely as a diagnostic tool for pituitary function rather than a therapy.
- Prohibited at all times in sport under WADA class S2.
Structure
How it works
GHRP-6 binds the growth hormone secretagogue receptor (GHS-R1a), the same receptor ghrelin acts on, triggering GH release from the anterior pituitary. It acts through a different receptor from the GHRH analogues, which is why the two classes are combined.
Its non-selectivity is the defining property. Activating GHS-R1a also drives ACTH and therefore cortisol, raises prolactin, and produces strong appetite stimulation — ghrelin is the hunger hormone, and GHRP-6 is a fairly direct mimic of it.
What the research shows
GH release in humans is well documented; GHRP-6 was studied as a pituitary function test and this effect is not in dispute.
What is not established is that raising GH pulses in a healthy adult produces the body-composition or recovery outcomes people use it for. That step has never been demonstrated in controlled trials.
The appetite effect is consistently reported and comes on within about 20 minutes.
Dosing in the literature
Figures below are quoted from published studies, with the species or population they were measured in. They are records of what was studied, not recommendations.
| Studied in | Amount | Route | Source |
|---|---|---|---|
| Human — GH stimulation and pituitary function testing | 1 µg/kg produces measurable GH response; 1–2 µg/kg used diagnostically | intravenous | PubMed |
Commonly reported ranges
These are amounts people report using. They are not from any study, have not been evaluated for safety, and are reproduced here only because they circulate widely and are better seen alongside the evidence than instead of it.
| Reported by | Amount | Route |
|---|---|---|
| Commonly reported | 100 µg, one to three times daily | subcutaneous |
No published human pharmacokinetic study establishes a dose, interval, or duration for this compound. Community figures below have no trial behind them and are reports of practice, not evidence. The cortisol and prolactin elevation is dose-dependent, which is the practical argument against pushing the amount upward rather than a theoretical one.
Handling and storage
Supplied as a lyophilised powder requiring reconstitution with bacteriostatic water. The powder is comparatively stable; once reconstituted it is refrigerated and used within weeks. Track the date you reconstitute each vial — the Inventory section does this, and it is the difference between knowing a vial is three weeks old and guessing.
Subcutaneous injection. Commonly dosed away from food, since elevated glucose and insulin blunt GH release. The hunger arrives quickly and is the main practical constraint on when it can be taken.
Side effects
Very common: intense hunger, and often a head-rush or flushing shortly after injection. Water retention, tingling in the hands, and lethargy are also reported.
The mechanistic concerns are cortisol and prolactin elevation. Sustained cortisol elevation works against most of the reasons people take a GH secretagogue in the first place, and elevated prolactin can cause gynaecomastia and reduced libido.
As with the whole class, raising GH carries potential for reduced insulin sensitivity, joint discomfort, and carpal tunnel symptoms. No long-term human safety data exists for this use.
Combinations
Conventionally paired with a GHRH analogue such as CJC-1295 or sermorelin, since GHRH and GHS receptors are separate and the combination produces a larger pulse than either alone.
GHRP-6 is largely superseded by ipamorelin for this role — ipamorelin achieves comparable GH release without the cortisol, prolactin, and hunger. If appetite stimulation is not the goal, GHRP-6 is the harder version of the same job.
Research status
Studied from the 1980s onward, initially as a tool for probing pituitary function. The GH-release literature is genuine. There is no completed trial of chronic use for body composition or recovery in healthy adults.
Legal status
Not approved for human use in any jurisdiction. Sold labelled for research use only. GH secretagogues appear on the FDA list of substances presenting significant risks for compounding.
WADA status
PROHIBITED AT ALL TIMES under WADA class S2 — growth hormone secretagogues, their releasing factors and mimetics are explicitly named. Any tested athlete should treat this as an anti-doping violation.
Conclusion
GHRP-6 reliably does two things: it raises GH, and it makes you extremely hungry. If the second is what you want, it is the most direct compound here for it.
If it is not, ipamorelin does the GH half without the cortisol, prolactin, and appetite — which is why most people who have used both end up there.
Sources
- [1]GHRP-6 — GH release and pituitary function testingPubMed
- [2]GHRP-6 effects on cortisol and prolactinPubMed
- [3]PubChem CID 4345065PubChem
- [4]WADA Prohibited List (current)WADA
Track your own GHRP-6 protocol
Peppers logs your doses, models your levels from this half-life, tracks your vials and tells you when you will run out. Free on iPhone.
Reference and educational information only. Not medical advice. Nothing here diagnoses, treats, or prescribes, and nothing here is a recommendation to use any compound. The compounds described are research chemicals and are not approved for human consumption. Legal and anti-doping status change — the review date above is when these claims were last checked. Talk to a qualified clinician about anything you intend to take.