GHRP-6

What is GHRP-6?

GHRP-6 is one of the original growth-hormone-releasing peptides, a synthetic hexapeptide that prompts your pituitary to release its own GH. It is best known for one blunt side effect: it makes you very hungry. That appetite spike is a direct signal from the ghrelin receptor, not a blood-sugar dip. Like the other GHRPs, it raises GH in a short pulse, but it is older and less selective than ipamorelin.

How GHRP-6 works

GHRP-6 is an agonist of the ghrelin receptor (GHS-R1a). Ghrelin, the hunger hormone, is the receptor's natural ligand, and activating it does two things at once: it drives a pulse of GH from the pituitary and it switches on appetite centers in the brain. Animal work showed that GHRP-6, like ghrelin, increases feeding, and that the effect runs through the brain's appetite circuitry rather than through low blood sugar. Because it acts on the ghrelin receptor, it is mechanistically separate from GHRH analogs like CJC-1295.

What the research shows

GHRP-6 has human data going back to the 1990s. One study in healthy men found it stimulated GH release along with sleep, ACTH, and cortisol, which is a clear signal that its effects are not confined to GH. The appetite effect is one of the most consistent findings across both animal and human research. As with the other GHRPs, the short-term hormonal response is documented, but there is no strong long-term trial base for the recovery, muscle, or anti-aging uses it is marketed for.

Dosage and how it is used

There is no approved dose for these uses. Community and clinic protocols commonly reference roughly 100 to 300 mcg subcutaneously, once to a few times per day. Because GHRP-6 raises appetite so strongly, some people use it deliberately for that effect and others avoid it for the same reason. These figures come from practice, not modern dose-finding trials.

→ How to reconstitute GHRP-6: calculator, units to draw & storage

Side effects and safety

The standout effect is hunger, which can be intense. Reports also include water retention, tingling, and, at higher doses, elevated cortisol and prolactin, because the ghrelin receptor also touches the stress-hormone axis. It is not FDA-approved for these uses, and there is no long-term human safety data at community doses.

• Strong appetite stimulation; can be a benefit or a drawback depending on your goal.
• Raises GH but also ACTH and cortisol; less selective than ipamorelin.
• Not FDA-approved. Verify current legal status independently.

Frequently asked questions

References

• Frieboes RM et al. Growth hormone-releasing peptide-6 stimulates sleep, growth hormone, ACTH and cortisol release in normal man. Neuroendocrinology, 1995.
• Lawrence CB et al. Acute central ghrelin and GH secretagogues induce feeding and activate brain appetite centers. Endocrinology, 2002.