Goal page
Peptides studied for skin, collagen and hair
GHK-Cu is the only peptide in our data with real human skin studies, and the best designed one found nothing. In 13 people after laser resurfacing, a copper peptide cream did not beat control on redness or wrinkles. Patients did say they liked it more. A separate 29 person scalp study had no comparison group.
Byline: PeptideGauge Editors. Sources checked 2026-08-24. Every study below links to its PubMed record. We do not publish amounts or schedules.
None of these is an approved medicine. Every peptide on this page is sold as a research chemical, none is approved by the FDA for any use, and for most of them the human safety record is a handful of people or nobody at all. This page tells you what has been studied. It does not tell you to use anything, how much, or how often. That belongs with a licensed doctor. Why we draw that line.
How we ranked these, before you see the ranking
The order below is arithmetic, not opinion. Each peptide gets four scores out of 100, and they are added up with fixed weights. Every score on this page is shown, so you can check the sum yourself or decide the weights are wrong.
- Evidence strength, 40 percent. The strongest single study we found for this goal. A randomised trial in people scores 100, a systematic review 75, a small human study 50, a review article 30, an animal study 25, cells in a dish 10.
- Human data, 25 percent. How many of the studies for this goal were done in people. None scores 0, one scores 40, two 60, three 80, four or more 100.
- Safety record, 20 percent. Some human safety reporting scores 70. Animal safety data only scores 35. No human safety data found scores 10. Nothing scores above 70, because nothing here has long term safety data in people.
- Regulatory clarity, 15 percent. An FDA approved drug scores 100. A substance on the FDA list of compounding nominations that were withdrawn scores 25. If the FDA also says it found no human exposure data, it scores 10.
Read the evidence score carefully. It measures how strong the study was, not how well the peptide worked. A well run trial that found nothing scores 100 here. The finding column tells you what it actually found, and on this site a well run trial that found nothing is the most useful kind of result there is.
Full rules and any changes to them: How we check.
The ranking
Sorted by total score. Every number that went into the total is in the row.
| Score | Peptide | Evidence 40% | Human data 25% | Safety 20% | Regulatory 15% | Strongest study we found |
|---|---|---|---|---|---|---|
| 73#1 | GHK-Cu The only peptide in our data tested on human skin in a controlled way. | 100evidence | 60human data | 70safety | 25regulatory | Human trial After laser skin resurfacing, a copper-peptide cream did not beat control on measured redness or wrinkles; patients did report liking it more. (n = 13) |
What counts as this goal: Studies about skin appearance, collagen, scalp and hair, in people or in human skin cells.
How to read the study tags
Cells in a dish means it never touched a living animal. Animals means mice or rats, usually. Small human study means a handful of people with no comparison group. Human trial means people were randomly split into treated and untreated groups, which is the only kind that can show an effect is real. Review and Systematic review sum up other studies. The full rule is on How we check.
GHK-Cu
A three amino acid peptide that binds copper. It is in human blood and the amount falls with age.
Score for this goal: 73 out of 100. The math: (100 x 40 + 60 x 25 + 70 x 20 + 25 x 15) divided by 100 = 73.
Safety, before the studies
Some human safety reporting exists. No skin reactions were flagged in the one small human trial, which used a cream rather than an injection. We found no published human safety data for injected GHK-Cu.
On the FDA list of substances nominated for compounding and then withdrawn. Nothing on this page is an approved drug. We do not publish amounts or schedules for any of it.
What has been studied for skin and aging
| Who or what was studied | What was found, and the catch | Source |
|---|---|---|
| Human trial n = 13 people | After laser skin resurfacing, a copper-peptide cream did not beat control on measured redness or wrinkles; patients did report liking it more. Limit: Thirteen people, a cream, one subjective win. | Miller 2006 PMID 16847171 |
| Small human study n = 29 people | A scalp routine with a copper-peptide serum plus a scrub reduced flaking over 15 days. Limit: No control group, company-employed authors, peptide mixed with other actives. | Patel 2024 PMID 39449909 |
| Review | Summarizes lab evidence that GHK can raise collagen and other skin-structure molecules. Limit: Same author group; no controlled human trial evaluated. | Pickart 2015 PMID 26236730 |
| Review | Questions whether GHK in skin products reaches where it would need to act, and calls the effectiveness data thin and inconsistent. Limit: Narrative review. | Mortazavi 2025 PMID 39963574 |
| Review | Reviews evidence that GHK-Cu changes the activity of many genes tied to repair and inflammation. Limit: Written by the peptide's discoverer; gene correlations, not patient outcomes. | Pickart 2018 PMID 29986520 |
Most cited author in this list: Pickart, 2 of 5 sources. When a small number of groups produce most of the evidence, independent replication is thinner than the source count suggests.
What is missing
- The one controlled human trial was negative on every measured outcome.
- Two of the five sources are reviews by the peptide's discoverer, which is a concentration of authorship worth knowing about.
- A 2025 review questions whether GHK in a skin product even reaches the layer it would need to act on.
- Every human study used a cream or serum on the skin. We found no human study of injected GHK-Cu at all.
What this page does not cover, and why
Cosmetic peptides such as argireline and matrixyl are sold for wrinkles and are not in our data yet, so they are not ranked here.
Sources
- Miller (2006). PMID 16847171
- Mortazavi (2025). PMID 39963574
- Patel (2024). PMID 39449909
- Pickart (2015). PMID 26236730
- Pickart (2018). PMID 29986520
FDA list of bulk drug substances nominated for compounding and withdrawn, last checked 2026-08-24: fda.gov. Every claim above is also on our evidence table.
Other goals
Injury recovery
Studies about healing damaged tendon, ligament, muscle, bone or joint tissue after an injury.
See the rankingWound healing
Studies about closing skin wounds, burns, and ulcers that will not heal.
See the rankingGut inflammation
Studies about inflammation of the bowel, in animals or in cells.
See the rankingMixing a vial? Do the math with the calculator.
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