Human study PLS-00026

Effects of topical copper tripeptide complex on CO2 laser-resurfaced skin.

Randomized controlled trial · Not reported participants enrolled

Version 1 · published November 7, 2026 · evidence through November 7, 2026 · research snapshot 2026.1.1 · methodology ev-1 · Automated assessment by AI (claude-opus-5-5 and claude-sonnet-5-5), not reviewed by a person.

Only the abstract was available. Essential methods may be missing, which limits what can be judged.

Reports of this study

Every publication, registration and abstract describing this one study. Participants are counted once.

Effects of topical copper tripeptide complex on CO2 laser-resurfaced skin.primary · Archives of facial plastic surgery · 2006-07-01 · PMID 16847171 · DOI

Design and participants

Design: Randomized controlled trial
Population: Patients meeting unspecified inclusion criteria who underwent circumoral skin resurfacing with a CO2 laser at standard settings
Conditions: CO2 laser-resurfaced skin, post-resurfacing erythema, facial wrinkles
Planned enrollment (registry): Not reported
Enrolled: Not reported
Randomized: Not reported
Completed follow-up: 13
Funding: PubMed lists the publication type Research Support, Non-U.S. Gov't; the funder is not named.
Authors’ conflicts: Not reported

Intervention and comparator

What each group received. Related peptides, analogs and combinations are never treated as the compound itself.

GHK-Cu skin care regimen (intervention) · ghk-cu (formulation) · Post-treatment skin care products containing copper tripeptide complex glycyl-L-histidyl-L-lysine-Cu(2+) (GHK-Cu) · topical · Post-treatment period after laser resurfacing, evaluated up to 12 weeks · Not reported assigned
Regimen without GHK-Cu (comparator) · Post-treatment skin care regimen without GHK-Cu; contents not described · other · topical · Post-treatment period after laser resurfacing, evaluated up to 12 weeks · Not reported assigned

What the authors reported

As stated in the sources. This is the authors’ account, not Peptide Library’s assessment.

Resolution of post-treatment erythema

unclear outcome · patient-important · Throughout the post-treatment period · Computer software analysis and blinded evaluators

GHK-Cu skin care regimen vs Regimen without GHK-Cu: narrative — No statistically significant between-group difference in earlier resolution of erythema

Overall improvement in wrinkles

unclear outcome · patient-important · 12 weeks after treatment · Evaluator assessment of overall wrinkle improvement

GHK-Cu skin care regimen vs Regimen without GHK-Cu: narrative — All patients improved significantly, with no difference between groups

Overall improvement in skin appearance

unclear outcome · patient-important · 12 weeks after treatment · Evaluator assessment of overall skin quality and appearance

GHK-Cu skin care regimen vs Regimen without GHK-Cu: narrative — All patients improved significantly, with no difference between groups

Patient-reported improvement in overall skin quality (questionnaire)

unclear outcome · patient-important · 12 weeks after treatment · Validated patient questionnaire completed before and 12 weeks after treatment

GHK-Cu skin care regimen vs Regimen without GHK-Cu: narrative, p = 0.04 — Significantly greater patient-reported improvement in overall skin quality with GHK-Cu

Adverse events

None reported. That is not evidence of safety.

Monitoring: Not reported in the abstract

The authors concluded (paraphrased): GHK-Cu skin care products after CO2 laser resurfacing did not reduce or speed resolution of erythema. Objective evaluation found no improvement in wrinkles or skin quality versus control, but patient satisfaction was higher with GHK-Cu.

Peptide Library’s assessment

An automated assessment, made by AI separately from the authors’ conclusions and not reviewed by a person. How risk of bias is assessed.

Limitations

small or imprecise: Only 13 patients completed the study, split across two arms. This gives little power to detect differences.
abstract only: Only the abstract is available. Methods, arm sizes, effect sizes and safety data cannot be checked.
inadequate randomization: The abstract states randomization but gives no method of sequence generation or allocation concealment.
inadequate blinding: Whether patients were blinded is not stated. The only significant finding was a patient-reported questionnaire outcome.
incomplete follow up: Numbers enrolled and randomized are not reported, so attrition before the 13 completers cannot be assessed.
inappropriate population: Participants had freshly CO2 laser-resurfaced circumoral skin. GHK-Cu was an adjunct to laser rather than a standalone treatment for aging skin.
selective reporting: No adverse event or tolerability data are reported, and effect sizes are given only as a single p-value.
short follow up: Outcomes were assessed only up to 12 weeks after treatment.

Resolution of post-treatment erythema: High risk of bias (Cochrane RoB 2)

Risk of bias in one result of a randomized trial, judged in five domains.

Domain judgments
Randomization process	Some concerns	Abstract states patients were randomized but gives no sequence generation, concealment or baseline balance details.
Deviations from intended interventions	Some concerns	Blinding of patients and adherence to the skin care regimens are not described in the abstract.
Missing outcome data	Some concerns	Only 13 completers are reported, and the number randomized is not given, so missing data are unknown.
Measurement of the outcome	Low risk of bias	Erythema was assessed with computer software and by blinded evaluators, as stated in the abstract.
Selection of the reported result	Some concerns	No protocol or registration is available, and the result is reported only narratively in the abstract.

Several domains raise some concerns from an abstract-only report with a very small sample, which substantially lowers confidence.

Version 1 · published November 7, 2026 · evidence through November 7, 2026 · research snapshot 2026.1.1 · methodology ev-1 · RoB 2 (2019-08-22) · Automated assessment by AI (claude-opus-5-5 and claude-sonnet-5-5), not reviewed by a person.

Overall improvement in wrinkles: High risk of bias (Cochrane RoB 2)

Risk of bias in one result of a randomized trial, judged in five domains.

Domain judgments
Randomization process	Some concerns	Randomization is stated, but method and allocation concealment are not reported in the abstract.
Deviations from intended interventions	Some concerns	Blinding of participants and adherence to the post-treatment regimens are not reported.
Missing outcome data	Some concerns	Thirteen completed, but numbers randomized and dropouts per arm are not reported.
Measurement of the outcome	Some concerns	The abstract says wrinkles were assessed but does not clearly state the assessor was blinded for this outcome.
Selection of the reported result	Some concerns	No prespecified analysis plan is available, and only a narrative no-difference statement is given.

Some concerns in all domains, from an abstract-only report of a small trial, lead to an overall high risk.

Overall improvement in skin appearance: High risk of bias (Cochrane RoB 2)

Risk of bias in one result of a randomized trial, judged in five domains.

Domain judgments
Randomization process	Some concerns	Randomization is stated, but method and allocation concealment are not reported in the abstract.
Deviations from intended interventions	Some concerns	Blinding of participants and adherence to the post-treatment regimens are not reported.
Missing outcome data	Some concerns	Thirteen completed, but numbers randomized and dropouts per arm are not reported.
Measurement of the outcome	Some concerns	Assessor blinding for overall skin appearance at 12 weeks is not explicitly stated in the abstract.
Selection of the reported result	Some concerns	No protocol is available, and the result is reported only narratively without estimates.

Some concerns across every domain in a tiny, abstract-only trial support an overall high risk of bias.

Patient-reported improvement in overall skin quality (questionnaire): High risk of bias (Cochrane RoB 2)

Risk of bias in one result of a randomized trial, judged in five domains.

Domain judgments
Randomization process	Some concerns	Randomization is stated, but method and allocation concealment are not reported in the abstract.
Deviations from intended interventions	Some concerns	Whether patients knew their assigned regimen is not reported, and adherence is not described.
Missing outcome data	Some concerns	Thirteen completers are reported, but the number randomized is unknown.
Measurement of the outcome	Some concerns	Subjective patient-rated outcome, and participant blinding to product is not reported in the abstract.
Selection of the reported result	Some concerns	The only significant result among several outcomes is reported as a lone p-value, with no prespecified plan available.

A subjective outcome with unknown blinding, plus multiple outcomes and some concerns in all domains, gives a high risk of bias.

Claims this study informs

Improves signs of skin aging: eligible for “Wrinkles and skin quality, measured or rated”, indirect evidence
Is safe for human use: not eligible (insufficient data) for “Adverse events, including skin reactions”

Very low certainty Wrinkles and skin quality, measured or rated

Where each value comes from

arms: PMID 16847171, abstract (Objective sentence 1 and Methods, sentence 2) · extracted by AI (automated, not verified by a person) · abstract only
author_conclusion: PMID 16847171, abstract (Conclusions, sentences 1-3) · extracted by AI (automated, not verified by a person) · abstract only
design: PMID 16847171, abstract (Methods, sentence 2) · extracted by AI (automated, not verified by a person) · abstract only
limitations: PMID 16847171, abstract (Results, sentence 1) · extracted by AI (automated, not verified by a person) · abstract only
outcomes: PMID 16847171, abstract (Methods, sentences 3-5) · extracted by AI (automated, not verified by a person) · abstract only
participants: PMID 16847171, abstract (Results, sentence 1) · extracted by AI (automated, not verified by a person) · abstract only
population: PMID 16847171, abstract (Methods, sentence 1) · extracted by AI (automated, not verified by a person) · abstract only
results: PMID 16847171, abstract (Results, sentences 2-4) · extracted by AI (automated, not verified by a person) · abstract only

Version 1 · published November 7, 2026 · evidence through November 7, 2026 · research snapshot 2026.1.1 · methodology ev-1 · Automated assessment by AI (claude-opus-5-5 and claude-sonnet-5-5), not reviewed by a person.

These assessments describe published research. Records marked automated were produced by AI under the published methodology and have not been reviewed by a person; they can contain errors. None of this is medical advice, not a statement about any product’s safety for human use, and not a regulatory approval. Peptide Library’s vendor and partner relationships play no part in them (editorial independence).