Peptides/Hormones and growth
GHRP-6
Also sold as Growth hormone releasing peptide-6, SKF-110679
The original growth hormone releasing peptide, and still the most reliable appetite stimulant of the whole family.
At a glance
What people use it for
- Appetite stimulation, which is its most reliable effect
- Marketed for muscle and recovery
- Sold in growth hormone peptide stacks
How it is taken
Sold as a powder for injection, often several times a day.
Evidence
No human trials yet
Best known for
- The compound that started this whole category
- Human pharmacology going back to the 1990s
- A strong, fast and predictable appetite effect
- Used as a research tool for probing pituitary function
GHRP-6 is the compound that started this category. It was the first growth hormone releasing peptide to be characterised properly, and the more selective compounds sold today, ipamorelin among them, were developed to keep its useful effect and lose the rest.
Knowing that it is the original explains most of what follows.
Why people are talking about it
Appetite. GHRP-6 acts at the ghrelin receptor, ghrelin is the hunger hormone, and the result is the most reliable appetite effect of anything in this family. People describe hunger arriving within twenty minutes and being hard to ignore.
That makes it genuinely useful to anyone struggling to eat enough, and precisely the wrong choice for anyone trying to eat less. Which of those a person is doing decides whether this compound makes sense at all.
What people take it for
Muscle and recovery on the label, appetite in practice.
Appetite
This is the claim that actually holds, and it is the most predictable thing about the compound. The mechanism is ghrelin receptor agonism, and the effect follows within the hour.
Muscle and recovery
The claim is more lean mass through raised growth hormone and IGF-1. The mechanism is genuine: a growth hormone pulse follows a dose reliably, which is well documented in human pharmacology studies from the 1990s.
Whether that pulse changes anything a person notices over months has not been tested, and no completed trial measures body composition in healthy adults taking it.
What the evidence shows
The human pharmacology is solid and old. Studies from the 1990s established that GHRP-6 raises growth hormone in people, and it was used as a research tool for probing pituitary function.
Development as a medicine did not proceed, so there is no completed efficacy trial for muscle, recovery or ageing.
The selectivity question is why later compounds followed it. GHRP-6 also raises cortisol and prolactin, and the pharmaceutical response was to design molecules that did not. Water retention, tingling in the hands and a head rush after a dose are commonly reported alongside the hunger.
How it is taken
Protocols circulating online describe subcutaneous injection several times a day, on an empty stomach, on the argument that food blunts a growth hormone pulse. Those schedules come from community practice rather than from a trial.
How it compares
Against ipamorelin
Ipamorelin was developed to do the useful part of what GHRP-6 does without the cortisol and prolactin effects, and in early studies it succeeded. GHRP-6 is cheaper and blunter; ipamorelin is cleaner.
Against CJC-1295
CJC-1295 works on a different receptor and produces a sustained rise rather than a pulse. They are frequently stacked, which makes attributing any single effect impossible.
Common questions
Why does it make me so hungry?
It acts at the ghrelin receptor, and ghrelin is the signal that produces hunger. The effect is the mechanism working rather than a side effect of something else.
Is it better than ipamorelin?
It is older and less selective. The main argument for it is cost.
Is it detectable in testing?
Yes. Growth hormone secretagogues are on the prohibited list in tested sport and are screened for.
Why several doses a day?
Its pulse is short. The sustained-release compounds in the family exist partly to avoid that.
Last reviewed .