GHRP-6

Hexapeptide growth hormone releasing peptide. Activates ghrelin receptor (GHS-R1a) with strong appetite stimulation via hypothalamic NPY/AgRP pathways. Produces robust GH pulse with concurrent increases in cortisol and prolactin. Synergistic with GHRH analogs for amplified GH release.

Half-life

15-60 minutes

Bioavailability

Systemic via subcutaneous injection

Route

subcutaneous

Evidence tier

T2 — Single-RCT or mechanistic

Optimization pillars

recovery · muscle

References

2 peer-reviewed

Dose ranges

Three tiers ordered by aggressiveness. Tier chips on every OPTIMIZE intervention let you filter the catalog by your evidence tolerance.

conservative

50–100 mcg/injection 1-2x/day

Mild GH elevation

moderate

100–200 mcg/injection 2-3x/day

GH and appetite

aggressive

200–300 mcg/injection 3x/day

Maximum GH output

Monitoring

igf-1
fasting-glucose
cortisol
prolactin

Contraindications

active-cancer
diabetes-uncontrolled
pituitary-tumor

References

PMID:9467534Growth hormone-releasing peptides: clinical and basic aspects — Growth Horm IGF Res, 1997
PMID:10372583Comparison of growth hormone secretagogues — Growth Horm IGF Res, 1999

Notes

GHRP-6 is the sledgehammer of the GH secretagogues. Big GH pulse. Big appetite increase. Cortisol and prolactin come along for the ride. If you are in a caloric surplus trying to gain mass, the appetite drive is a feature. If you are trying to stay lean, it is a bug. Ipamorelin exists specifically because GHRP-6's side effect profile motivated the search for selectivity. Use GHRP-6 when you want the appetite. Use ipamorelin when you do not.

This is not medical advice

Discuss with a licensed clinician before starting, stopping, or changing any compound. This page documents what the research literature describes — it is not a prescription.

See GHRP-6 in a protocol matched to you