About
How we find, verify and grade research
How GHK-Cu studies are found in PubMed, verified, graded A–D, separated by route, and reviewed before publication.
By the GHK-Cu Peptide editorial team · Last reviewed · Editorial review: pending
Short answer
Every study on this site was found through PubMed, has its bibliographic details pulled from PubMed’s own records, is summarised as what the study measured in which model and by which route, is graded by the kind of evidence, and carries a review status. Regulatory statements quote the regulator’s own record with a retrieval date.
1. Search
We query PubMed titles and abstracts for GHK-Cu, copper tripeptide, glycyl-histidyl-lysine, glycyl-L-histidyl-L-lysine, Gly-His-Lys, GHK copper, GHK-copper and prezatide. The November 2026 run returned 259 records [PubMed search]. Each is screened by title and abstract. We keep studies that tested GHK or GHK-Cu, flag derivatives and multi-ingredient products, and keep reviews for context. We leave out records where the sequence appears only as part of a larger protein, and disease-model studies outside the six research categories on this site.
2. Verify
- Title, journal, year, authors and DOI come from PubMed E-utilities, never retyped.
- Each summary is checked against the abstract. Where the abstract does not give a sample size, the record says so.
- Author affiliations quoted on this site are taken from PubMed’s affiliation field.
- Chemical identity comes from PubChem and FDA’s substance registry, with each value attributed. No coordinates or properties are computed by us.
- An automated check re-resolves every PMID and DOI before each release.
3. Describe what was measured, and by which route
Summaries make the study the subject and state what was measured in which model. Each record is tagged with its route of exposure (applied to skin, added to cell culture, injected into an implanted chamber, and so on) and with the substance actually tested (GHK-Cu, copper-free GHK, a derivative, or a multi-ingredient product). Records with different routes are never pooled.
4. Grade
| Grade | Meaning | Records |
|---|---|---|
| A | randomised controlled human study | 3 |
| B | other human study (uncontrolled, case or multi-ingredient) | 7 |
| C | animal (in vivo) study | 10 |
| D | cell, tissue or chemistry study | 45 |
| R | review or commentary (context, not evidence) | 16 |
Grades describe the kind of evidence, not its quality or direction. A grade A trial can be null; a grade C study can be well conducted and still say nothing about people.
Model types
- Human study
- Animal (in vivo)
- Ex vivo (excised tissue, no one received the substance)
- In vitro (cells)
- Chemistry and analytical
- Review or commentary
5. Review before publication
Each study record, source and related-resource link carries a review status (pending, approved or rejected) and shows it. The production build can be set to refuse any page that cites a record not yet approved by a named reviewer. See the editorial policy.
6. Keep current
The corpus was last verified on 2026-11-11. Searches are re-run and regulatory pages re-checked at each review, and pages show their last-reviewed date.
References
- PubMed, National Library of Medicine. PubMed search: GHK-Cu, copper tripeptide, glycyl-histidyl-lysine, Gly-His-Lys, prezatide (title/abstract). Source[retrieved 2026-11-11]