GHK-Cu (Copper Peptide) vs Palmitoyl Tetrapeptide-7
A naturally occurring copper peptide that acts like a master switch for your body's repair systems—boosting collagen production, accelerating wound healing, and helping your skin rebuild itself from the inside out [1][4].
Anti-inflammatory matrikine peptide that reduces IL-6-driven inflammaging for calmer, more youthful skin.
Written by Michael Carroll — Owner, Director of Research · Reviewed by the Peptide Initiative Research Team · Editorial standards
Quick comparison
Dose range
GHK-Cu (Copper Peptide)
0.1–0.1 %
Palmitoyl Tetrapeptide-7
3–3 %
Frequency
GHK-Cu (Copper Peptide)
Once or twice daily, topical
Palmitoyl Tetrapeptide-7
Once daily
Administration
GHK-Cu (Copper Peptide)
Subcutaneous injection
Palmitoyl Tetrapeptide-7
Topical
Cycle length
GHK-Cu (Copper Peptide)
12 weeks, then ongoing
Palmitoyl Tetrapeptide-7
Ongoing/indefinite
Onset speed
GHK-Cu (Copper Peptide)
Moderate (1-2 weeks)
Palmitoyl Tetrapeptide-7
Moderate (1-2 weeks)
Evidence level
GHK-Cu (Copper Peptide)
Strong preclinical (extensive animal studies)
Palmitoyl Tetrapeptide-7
Limited human trials
Benefit ratings
Skin Rejuvenation
Wound Healing
Tissue Regeneration
Anti-Inflammatory
Anti-Aging
Skin Barrier Support
Compound specifications
GHK-Cu (Copper Peptide)
Molecular formula
C14H23N6O4Cu
Molecular weight
403.93 g/mol
Half-life
Approximately 1 hour (plasma)
Bioavailability
High when injected subcutaneously; variable topically depending on formulation
CAS number
49557-75-7
Palmitoyl Tetrapeptide-7
Molecular formula
C34H62N8O7
Molecular weight
694.9 Da
Half-life
Susceptible to enzymatic degradation; palmitoyl anchor reduces proteolytic cleavage rate compared to unmodified peptide
Bioavailability
Enhanced topical penetration via palmitoyl lipid modification enabling membrane interaction and dermal delivery
CAS number
221227-05-0
Dosing compared
GHK-Cu (Copper Peptide)
Topical
0.1% cream (roughly 1 mg/mL)
Once or twice daily to the treatment area · 12 weeks for visible results, then ongoing
This is the only GHK-Cu route with a controlled human trial behind it, and the trial was largely negative. Thirteen patients used a GHK-Cu aftercare regimen after CO2 laser resurfacing; blinded assessment found no significant improvement in redness, wrinkles or overall skin quality versus the control regimen, and only the patients' own rating separated (P = 0.04) [7]. Topical wound-healing evidence beyond that is animal — 24 rats with ischemic wounds, where the copper tripeptide gel reduced wound area faster than vehicle [4]. Concentration matters and is not standardised across products; the figures quoted for cosmetic creams come from industry reports rather than independent trials [1][2].
Subcutaneous
No established human dose
Not established · Not established
There are no human studies of injected GHK-Cu by any systemic route. The GHK-Cu studies registered on ClinicalTrials.gov are topical or transdermal [13]. The 1-2 mg figures circulated for subcutaneous use trace to community practice, not to any published study, and no human toxicology exists for the copper load a systemic dose would deliver. The Pickart literature most often cited for GHK-Cu is mechanistic and wound-repair work, not injectable dosing [1][2][3].
Palmitoyl Tetrapeptide-7
Topical
Under 10 ppm (<0.001%) in finished product
Once or twice daily · Ongoing
Customary leave-on cosmetic use is below 10 ppm of the active peptide [6]. Pal-GQPR is almost always used as a co-active alongside Pal-GHK in the Matrixyl 3000 blend rather than on its own.
~3% trade solution (Matrixyl 3000 blend)
Twice daily · ~2 months
In manufacturer clinical testing the trade-solution blend was applied twice daily for about two months [6]. The ~3% figure refers to the diluted trade solution, which contains only ppm-level active peptide.
Best suited for
GHK-Cu (Copper Peptide)
Anti-Aging Warriors
If fine lines, sagging skin, and lost elasticity are your enemies, GHK-Cu is your secret weapon. It ramps up collagen and elastin production—the two proteins responsible for keeping your skin firm and youthful [1][2]. Studies show it can tighten loose skin and improve elasticity better than many popular skincare ingredients [1][2].
Wound Healing Champions
Whether you're recovering from surgery, dealing with stubborn wounds, or healing from a cosmetic procedure, GHK-Cu accelerates the entire repair process [4]. It attracts immune cells, builds new blood vessels, and stimulates the growth factors your body needs to rebuild tissue faster and better [1].
Scar Reducers
GHK-Cu doesn't just heal wounds—it helps remodel scar tissue. By regulating how your body lays down collagen during healing, it can help scars become flatter, softer, and more like surrounding normal skin [6]. It even reduces the TGF-beta signals that lead to thick, raised scars [12].
Hair Growth Seekers
Research shows GHK-Cu can enlarge hair follicles and activate the Wnt/beta-catenin pathway—the signaling system that tells hair follicles to grow [1]. If you're noticing thinning hair or increased shedding, this peptide may help stimulate thicker, healthier growth over time.
Palmitoyl Tetrapeptide-7
Individuals with aging skin showing signs of chronic low-grade inflammation
Palmitoyl Tetrapeptide-7 is particularly well-suited for individuals focused on individuals with aging skin showing signs of chronic low-grade inflammation. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Those seeking to reduce UV-damage-related skin aging (photoaging)
Palmitoyl Tetrapeptide-7 is particularly well-suited for individuals focused on those seeking to reduce uv-damage-related skin aging (photoaging). Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
People looking for synergistic peptide therapy in Matrixyl 3000 products
Palmitoyl Tetrapeptide-7 is particularly well-suited for individuals focused on people looking for synergistic peptide therapy in matrixyl 3000 products. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Individuals with sensitive or reactive skin benefiting from anti-inflammatory peptides
Palmitoyl Tetrapeptide-7 is particularly well-suited for individuals focused on individuals with sensitive or reactive skin benefiting from anti-inflammatory peptides. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Side effects
GHK-Cu (Copper Peptide)
Common
- Injection site redness
- Skin tingling (topical use)
- Minor bruising
- Mild swelling at injection site
Uncommon
- Mild headache
- Temporary skin purging (topical)
Serious
- Allergic reaction
Palmitoyl Tetrapeptide-7
Common
- Mild Redness
- Slight Tingling
- Mild Irritation with Other Actives
- Dryness
Uncommon
- Allergic Contact Dermatitis
Serious
- Paradoxical Inflammatory Response
Safety & evidence
GHK-Cu (Copper Peptide)
Evidence level
Strong preclinical (extensive animal studies)
FDA status
Research compound
Safety overview
GHK is a peptide the body makes on its own — it turns up in human blood serum and cerebrospinal fluid, where it binds copper [5]. The peptide's original describer reports that the amount circulating falls with age, from roughly 200 ng/mL around age 20 to about 80 ng/mL by age 60 [2]. That is a description of what declines, not evidence that replacing it does anything. Almost all of the safety evidence is topical or laboratory work. The one randomized human trial of topical GHK-Cu — 13 patients using it after CO2 laser resurfacing — reported no safety problems, but also found no objective benefit over the control regimen [7]. There is no human safety data for injected GHK-Cu by any route [13]. That matters more than usual here, because the molecule carries copper: a systemic dose delivers a copper load, and no human toxicology study has measured what that load does.
Contraindications
- Wilson's disease or copper metabolism disorders
- Known allergy to copper or peptide components
- Active cancer or history of cancer
- Pregnancy or breastfeeding
- Children and adolescents
Palmitoyl Tetrapeptide-7
Evidence level
Limited human trials
FDA status
Research compound
Safety overview
Palmitoyl tetrapeptide-7 (Eyeliss) shows excellent safety for periocular use with minimal irritation potential (Draize score <0.5 at 2% concentration). No serious adverse events in cosmetic formulations used for 15+ years. Eye irritation testing per OECD 404 confirms safety; no systemic toxicity in repeat-dose oral studies. Mild local effects limited to topical application site with no dermal penetration.
Contraindications
- Known hypersensitivity to palmitoyl tetrapeptide-7 or formulation excipients
- Active skin infections at the application site
- Severely compromised skin barrier with active inflammation requiring medical intervention
- No known systemic contraindications at cosmetic concentrations
Which is right for you?
Choose GHK-Cu (Copper Peptide) if...
- Skin rejuvenation and anti-aging
- Wound and injury recovery
- Scar reduction
- Hair growth support
Choose Palmitoyl Tetrapeptide-7 if...
- Individuals with aging skin showing signs of chronic low-grade inflammation
- Those seeking to reduce UV-damage-related skin aging (photoaging)
- People looking for synergistic peptide therapy in Matrixyl 3000 products
- Individuals with sensitive or reactive skin benefiting from anti-inflammatory peptides