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Evidence-rated reference Updated August 2026
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Research Use Only Growth Hormone Axis Evidence 2/5 · Limited

GHRP-6

Also known as Growth Hormone Releasing Hexapeptide

First-generation growth hormone-releasing hexapeptide

Overview

The compound that opened up the whole GHS field — it led directly to the discovery of the ghrelin receptor. As a therapy it is crude: powerful hunger stimulation and hormonal cross-talk made it impractical.

Not approved for human use anywhereNo approval anywhere for human use. Sold under research-use labelling. Not approved for human use in any major market.

At a glance
Regulatory statusNot approved. Superseded by more selective secretagogues; largely of historical and research interest.
Drug classFirst-generation growth hormone-releasing hexapeptide
RouteSubcutaneous (research)
Half-life~15–60 minutes
Evidence rating
2/5 Limited Evidence rating 2 out of 5: Limited
Preclinical work plus scattered human reports, uncontrolled use, or negative trials.
Studied inExtensive endocrine pharmacology research; small cardioprotection studies; no completed therapeutic development program.

How it works

Ghrelin receptor agonism with substantial off-target activation of ACTH/cortisol and prolactin release, plus strong central appetite stimulation.

Evidence base

Rated 2 of 5 — Limited. Preclinical work plus scattered human reports, uncontrolled use, or negative trials.

  • Historically important research tool; no therapeutic evidence base.

Benefits & potential uses

Bars indicate how well each claim is supported: three = strong human evidence, two = moderate, one = preliminary or preclinical.

  • Powerful appetite stimulation Moderate evidence

    Among the strongest orexigenic effects of any peptide — potentially useful in cachexia, and unwanted in almost every other context.

  • Reliable GH release Moderate evidence

    Effective as a pituitary stimulus, historically important for characterising the GH axis.

  • Preclinical cytoprotective signals Preliminary

    Animal work suggests cardioprotective and gastric-protective effects.

Risks, cons & cautions

Bars indicate seriousness: three = serious or common, two = moderate, one = minor.

  • Intense hunger Moderate evidence

    Often sabotages the body-composition goals people take it for.

  • Cortisol and prolactin elevation Moderate evidence

    More pronounced than with newer secretagogues; chronic elevation carries real endocrine consequences.

  • No approved use anywhere Serious

    Never completed clinical development.

  • Rapid desensitisation Moderate evidence

    Response falls off with repeated dosing.

  • Unregulated supply Serious

    Research-chemical market only.

  • WADA prohibited Minor

    Banned at all times in tested sport.

Who should avoid it

  • Active malignancy
  • Pregnancy
  • Hyperprolactinemia
  • Diabetes

If used under medical supervision, monitor

  • IGF-1, prolactin, cortisol
  • Glucose

Not approved for human use in any major market.

Infographic

GHRP-6 — benefits & risks at a glance Download SVG
Infographic summarising the benefits and risks of GHRP-6, from pepteyes.com

Where to read further

We link to live literature searches rather than a frozen citation list, so you always see current results — including anything published after our last review.

growth hormoneghrelinappetiteresearch chemical

Related peptides in Growth Hormone Axis

Terms used on this page

Growth Hormone Secretagogue Receptor (GHS-R1a)
GHS-R1a is the G protein-coupled ghrelin receptor mediating growth hormone release and appetite, notable for unusually high constitutive activity in the complete absence of any ligand.
Off-Target Activity
Off-target activity is any interaction a compound has with proteins other than its intended target, and it is a matter of degree rather than a property a drug either has or lacks.
Prolactin
Prolactin is a 199-amino-acid anterior pituitary hormone held under tonic dopamine inhibition, central to lactation and the marker of prolactinomas and drug-induced hyperprolactinaemia.
Cortisol
Cortisol is the principal human glucocorticoid, secreted by the adrenal cortex under ACTH control on a pronounced daily rhythm and carried in plasma largely bound to corticosteroid-binding globulin.
Agonist
An agonist is a ligand that binds a receptor and stabilises its active conformation, producing a biological response rather than merely occupying the binding site.
Ghrelin
Ghrelin is a 28-amino-acid stomach peptide that must carry an octanoyl group on serine 3 to activate GHS-R1a, where it drives both growth hormone release and appetite.

This page is educational information, not medical advice. It cannot account for your medical history, medications, or risk factors. Do not start, stop or change any treatment based on it. Speak to a qualified healthcare professional who knows your case.