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Peptide Evidence Registry

Skin & hair · Tissue repair · Cosmetic & aesthetic

GHK-Cu

Decent cosmetic evidence on the skin, very different question when people inject it.

L3Early human studiesCosmetic / topical productUnclear
How settled this rating is:
low confidence in the current evidence rating
Routes studied:
Topical · Subcutaneous injection (marketed but never approved)
Also known as:
copper tripeptide-1, glycyl-L-histidyl-L-lysine copper
Last reviewed:
2026-08-23
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Evidence passport

GHK-Cu

A one-screen evidence identity for this compound. These fields describe research maturity, confidence and legal status. They are not a safety guarantee, efficacy percentage or recommendation.

Reviewed 2026-08-23
Evidence level
L3Early human studies
Confidence
Low confidence in rating
Regulatory status
Cosmetic / topical product
Development status
Unclear

Evidence strength

Human efficacy evidence40 of 100 evidence strength

Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.

Human safety evidence50 of 100 evidence strength

Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.

The 0-100 values rate the strength and maturity of evidence, not how effective or safe the compound is.

Evidence base
Includes human studies
Furthest established stage
Not established
Human research maturity
Cosmetic human studies for topical use; no established systemic clinical use
Source curation
Sources fully curated

Routes recorded

TopicalSC injection· unapproved

Overview

Human efficacy evidence strength40 of 100 evidence strength

Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.

Preclinical (animal / lab) evidence strength68 of 100 evidence strength

Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.

Human safety evidence strength50 of 100 evidence strength

Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.

How to read these scores

Every number here rates the evidence, not the compound. They are editorial 0-100 strength ratings, not percentages, and not a rating out of five stars.

  • Human efficacy evidence strength — Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.
  • Preclinical evidence strength — Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.
  • Human safety evidence strength — Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number. A score of 80 does not mean “80% safe”.
  • Evidence level (L0-L5) — the strongest type of study behind the compound, from anecdote (L0) to large replicated human trials (L5). It is a description of the study evidence, not a quality, safety or recommendation rating.
  • Confidence — how likely we think it is that this rating changes as new research lands. Low confidence means the picture is unsettled, not that the compound is bad.

None of these ratings is medical advice, a safety guarantee, or a recommendation to use anything. How we grade evidence.

How far human research has progressed: Cosmetic human studies for topical use; no established systemic clinical use

Routes & formulations

Studied / approved routes

Topical

Marketed / research routes — never approved

SC injection· unapproved

This is the registry's clearest example of route confusion. Small human cosmetic studies apply to topical creams and serums. They say nothing about injecting GHK-Cu — a different exposure, with no controlled human evidence and an explicit FDA compounding safety flag.

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

Marketed as a cosmetic ingredient; no established pharmaceutical development programme for systemic use.

What it is

A naturally occurring copper-binding tripeptide found in plasma, saliva and urine, used in cosmetics for skin remodelling.

What people claim

  • Reduces wrinkles and improves skin firmness
  • Regrows hair
  • Systemic anti-ageing and wound healing when injected

What the evidence actually says

Topically, there are small human cosmetic studies suggesting improvements in skin appearance — modest effects, small samples, often industry-linked, but not nothing. Systemic injectable use is a completely different exposure with essentially no controlled human evidence. Treating those two as the same claim is the main error people make here.

Related evidence

Useful next reads based on this compound — not recommendations.

Human evidence

  • Small randomised and controlled cosmetic studies of topical formulations reporting improvements in skin appearance.
  • No controlled human trials of injectable systemic administration for anti-ageing.

Preclinical evidence

  • Cell and animal studies of collagen synthesis, wound healing and antioxidant effects.
  • Gene-expression work suggesting broad modulation of repair pathways.

Animal and cell findings are Level 1–2 evidence.

Mechanism and pathways

  • Delivers copper, a cofactor for lysyl oxidase and other enzymes involved in collagen and elastin cross-linking.
  • Stimulates dermal fibroblast activity and extracellular matrix remodelling.

Safety and unknowns

  • Topical use is generally well tolerated in cosmetic studies.
  • Systemic copper-containing peptide administration raises copper-balance questions that have not been studied properly in humans.

Cancer relevance

This section covers questions raised by how the compound works in the body, plus anything regulators and trial teams keep an eye on. It is not a statement that this compound causes cancer — for most compounds here, no human data exist in either direction.

Theoretical / mechanistic concern only

Copper availability and angiogenesis both have roles in tumour biology, which makes systemic dosing a theoretical question worth flagging. There is no human evidence of cancer causation from GHK-Cu, topical or otherwise.

Regulatory status

Regulatory decisions apply to specific jurisdictions, products, formulations and indications. An approval elsewhere is not automatically an approval in your country.

Check the regulatory note and linked primary sources for jurisdiction-specific details.

Widely used as a cosmetic ingredient in topical skincare. Injectable systemic use is not an approved medical treatment, and FDA has treated injectable GHK-Cu as a bulk substance raising significant safety risks for compounding. That listing status changed during 2026 and the substance was covered by FDA's July 2026 advisory committee review.

Evidence grade

L3Early human studiesLow confidence in rating

Preliminary human outcome research, including small or observational studies. Descriptive exposure studies alone do not demonstrate therapeutic benefit.

What would change our rating?

  • Larger independent topical trials with objective endpoints.
  • Any human safety data for systemic administration.

References and sources

Source transparency

A provenance snapshot of this profile. Counts show what kinds of sources are cited, not how much scientific weight each source deserves.

Sources fully curated
Last editorial review
2026-08-23
Recently reviewed · 54 days ago
Linked curated sources
3
Sources still pending
0
External specialist reviews
0
None recorded for this profile
Regulatory / label: 3

Review provenance

Registry editorial review: Colin Jackson-White, creator and editor, who is not a doctor or clinician. External specialist review is credited only when a named reviewer has completed a review of this exact profile.

Literature-discovery and AI tools may help locate or challenge candidate evidence, but they are not counted as evidence sources here. Registry judgements are tied to the underlying papers, trial records, regulator documents and official study records.

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

These entries record changes to our assessment of the published evidence — not changes to the compound itself.

  1. Baseline entry: topical and systemic evidence separated into distinct positions.

    Change 1 of 1
    L3Early human studiesEvidence rating changedBaseline entry
    Small topical cosmetic studies support modest skin-appearance effects. Injectable systemic use has no controlled human evidence and is rated independently.

Related claims we’ve checked — in full

Claim verdict

Skin & hair

Not supported as wordedL3Early human studies

“GHK-Cu injections give you the same benefits as the skincare studies.”

This verdict applies to the exact claim above. It is not a verdict on the compound overall, a safety guarantee, or a recommendation to use it.

Registry verdict

Unsupported — topical evidence does not transfer to systemic dosing.

Why this verdict

  • The human evidence is for topical cosmetic formulations with local skin endpoints.
  • Injecting a copper-carrying peptide is a fundamentally different exposure with different risks, including copper balance.
  • No controlled human trials support systemic injectable use.