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Growth hormone axis

GHRP-6

The older sibling of GHRP-2, with historical human pharmacology but no approved indication and a notable appetite-stimulating effect.

L2PreclinicalExperimental / researchUnclearVery low confidenceLast reviewed 2026-08-23
SC injection· unapproved

Also known as: growth hormone releasing peptide-6

Evidence passport

Last reviewed 2026-08-23

Evidence level
L2Preclinical
Confidence
Very low confidence
Human efficacy
20/100
Human safety
10/100
Regulatory status
Experimental / research
Development
Unclear
Routes
SC injection· unapproved
Evidence base
Mostly preclinical
Furthest stage
Not established
Source curation
Sources partially curated
Clinical maturity
Historical human pharmacology only

Most of this evidence comes from animals and cells

The supporting research for GHRP-6 is predominantly preclinical (Level 1–2). That is a legitimate starting point for science and a poor basis for personal decisions. Human results are not simply a scaled-up version of mouse results.

Overview

Human evidence20/100
Preclinical evidence45/100
Human safety evidence10/100

Clinical maturity: Historical human pharmacology only

Routes & formulations

Marketed / research routes — never approved

SC injection· unapproved

Research-market products are injectable and unapproved; no studied therapeutic route is established in the curated record.

Route availability is not evidence of efficacy, and evidence from one route does not transfer to another. The Registry never provides dosing or sourcing information.

Peptide lifecycle

  1. Discovery

  2. Preclinical

  3. Phase I

  4. Phase II

  5. Phase III

  6. Approved

UnclearFurthest stage not established in our curated record

No established development programme in the curated record.

What it is

A synthetic hexapeptide GH secretagogue from the same research era as GHRP-2, distinguished by stronger appetite stimulation via ghrelin-receptor activity.

What people claim

  • Builds muscle and reduces fat via growth hormone
  • Anti-ageing benefit

What the evidence actually says

Human studies from the 1990s confirmed GH release; everything marketed beyond that is extrapolation. No controlled trials support body-composition or performance claims.

Human evidence

  • Early human pharmacology studies confirming GH and appetite effects.
  • No controlled trials for any marketed claim.

Preclinical evidence

  • Ghrelin-receptor pharmacology and animal GH-axis studies.

Animal and cell findings are Level 1–2 evidence.

Mechanism and pathways

  • GHSR-1a agonism drives GH pulses; the same receptor mediates hunger, which is why appetite increases.

Safety and unknowns

  • No long-term human safety dataset for chronic use as actually sold.
  • Appetite stimulation is often the opposite of what buyers intend.

Cancer relevance

Theoretical / mechanistic concern only

Indirect IGF-1 elevation carries the same theoretical proliferation concern as the rest of the GH axis. No human cancer outcome data exist.

Regulatory status

Not an approved medicine in any major region; sold in the research market for physique and anti-ageing claims that have never been trialled.

Evidence grade

L2PreclinicalVery low confidence

Animal, organoid or tissue studies. Mice are not tiny humans.

What would change our rating?

  • Controlled trials with body-composition or functional endpoints.
  • Modern safety data for chronic administration.

References and sources

Sources partially curated

Source hierarchy: regulatory documents and trial registries first, peer-reviewed work next, sponsor material flagged as non-independent. We never use supplier or clinic marketing as evidence, and where a verified source has not yet been curated we say so rather than inventing one.

Evidence change history

No recorded changes yet. Baseline position set on 2026-08-23.