Peptides
GHK-Cu (Copper Peptide)
Also called Copper Tripeptide-1
GHK-Cu is used for smoother, firmer-looking skin and is also researched for fuller hair. Small topical studies suggest possible cosmetic benefits, but results depend on the product. Injections have not been shown to give better skin or hair results.
Dosage & duration
Topical product instructions and a clinic-reported injection example are separate, not interchangeable doses.
Face serum — The Ordinary Multi-Peptide + Copper Peptides 1%
Product label- Dose
- A few drops to the face
- How often
- Morning and evening
- How long
- Daily skin-care routine; no fixed course stated
Finished multi-ingredient cosmetic for unbroken skin. The product name’s percentage is not an injected amount.
Sources: 1
Clinic-reported example — subcutaneous GHK-Cu, Trusta
Reported use · unapproved regimen- Dose
- 1–2 mg per day
- How often
- Daily
- How long
- 4–8 weeks, then reassessment
This clinic’s published dosing example, not a validated skin or hair regimen. Vial strength is unspecified; no syringe-unit conversion is supplied.
Sources: 6
A topical percentage, drops of a finished product and milligrams injected are different measurements. FDA reports limited human safety data for injectable GHK-Cu.
The practical difference
Topical versus injectable GHK-Cu
For skin texture, fine lines or fuller hair, the route changes which evidence applies.
| Practical difference | Applied to skin | Injected under skin |
|---|---|---|
| What people seek | Local skin-care or hair effects | Wider repair and anti-aging effects |
| What the amount describes | A concentration and amount of finished serum | Milligrams of peptide per dose |
| What results tell us | Small, product-specific human studies | No demonstrated cosmetic advantage over topical use |
What do people want from GHK-Cu?
The main appeal is appearance: softer-looking fine lines, smoother texture, firmer skin and fuller hair. Copper-peptide serums target those skin-care goals, while injectable GHK-Cu is promoted for broader repair and anti-aging effects. These are different products with different evidence, so the first useful choice is the goal and route—not the biggest number on a vial.
Does it improve skin texture or wrinkles?
There are encouraging findings, but no dependable percentage improvement to promise. In a 2026 study, 30 people completed eight weeks using a cream with GHK-Cu and a ferment extract. Several skin measures improved. Because everyone used the combination cream, the study could not separate the peptide’s contribution from the rest of the formula or other changes over time.
Results are not uniformly positive. A small randomized study after CO2 laser resurfacing found higher satisfaction with a GHK-Cu skin-care regimen but no clear advantage in measured wrinkles, redness or overall skin quality. Those studies support realistic expectations for a particular product, not claims that a shot will erase scars or reverse aging.
What about hair growth?
The most direct recent result here is about eyebrows. An 18-person study compared 2% GHK-Cu serum applied twice daily to one eyebrow with a serum without the active ingredient on the other. After 12 weeks, the researchers reported better hair count and thickness on the GHK-Cu side.
That is an early signal, not proof that a face serum or an injection reverses scalp hair loss. Eyebrow enhancement, pattern hair loss and shedding during weight loss are different questions. A cosmetic ingredient should not replace assessment of why hair is thinning.
Topical or injectable: what changes?
A finished serum is applied to the skin and includes a complete formula, not just GHK-Cu. The Ordinary’s example also contains other peptides and moisturizing ingredients. Its directions therefore belong to that product; its advertised percentage cannot be converted into an injection dose.
Published clinic injection schedules do exist, and a clearly attributed example is shown in the dose section. That is a published dosing example, not evidence that injections outperform topical products. FDA specifically notes limited human safety information for injectable GHK-Cu and concerns about immune reactions related to peptide aggregation or impurities.
How long should results take, and what about irritation?
The topical studies discussed here assessed changes over eight or twelve weeks. These are study windows, not a guarantee of visible results by a particular week. A stronger serum has not been established as a faster or better option by those studies.
For the named face serum, the manufacturer advises a patch test, use on unbroken skin and stopping if irritation occurs. It also gives product-specific compatibility advice for acids, retinoids and vitamin C. Follow the finished product’s directions rather than treating every copper-peptide formula as interchangeable.
What does the plotter tell me?
The plot uses relative units and assumed timing. It does not predict an injected blood level, collagen changes, hair growth or how much peptide from a serum reaches the skin. Use the route-specific examples and study outcomes to understand those questions.
Model details: GHK-Cu (Copper Peptide) · relative timing
Compare timing and buildup for this compound. The values are not blood concentrations or a measure of strength.
Shows a relative timing scenario; absolute blood concentrations are not calibrated.
Timing assumptions and sources
Legacy 0.96 h is unverified for administered-human intact GHK-Cu. No quantitative timing is imported from free-GHK degradation.
One 1 mg input peaks at 1 relative unit after a single dose. Other amounts scale proportionally; overlapping doses add when accumulation is on. Different compounds use separate relative scales.
- Timing half-life used
- 0.96 hours
- Absorption half-life assumed
- 0.24 hours
- Reference amount for the relative scale
- 1 mg
- Absorption half-life is assumed to be one quarter of the slower timescale (0.24 h); it is not a measured absorption parameter.
- A single 1-unit input has a peak of 1 relative unit; scaling and repeated-dose addition are mathematical assumptions. This normalization is independent of the example dose.
- Free GHK, intact GHK-Cu, total copper and endogenous baseline GHK are different analytes.
- Topical cosmetic concentrations and assay calibration ranges are not plasma Cmax.
- In vivo stimulation of connective tissue accumulation by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+ in rat experimental wounds.
Legacy 0.96 h is unverified for administered-human intact GHK-Cu. No quantitative timing is imported from free-GHK degradation.
- 1997 original rat GHK/HK analytical PK paper
GHK acetate given IV to rats, rapidly degraded toHK; freeGHK is not intactGHK-Cu.
ghk-cu-relative-timing-2026-10 · version 1
Common questions
Is injectable GHK-Cu better than a serum for skin?
No reliable head-to-head evidence establishes that. Topical products have small human appearance studies; a clinic injection schedule does not show better cosmetic results.
Does GHK-Cu regrow scalp hair?
Scalp regrowth is not established by the small eyebrow study described here. That study reported eyebrow improvements with a specific topical serum; it did not test baldness treatment or injections.
Is a 2% or 4% serum better than a 1% product?
Those percentages may describe different finished formulas, and the studies do not establish a simple higher-is-better rule. Compare the actual ingredients, intended application and product directions; do not convert a cosmetic percentage into an injection dose.
Can I use copper peptides with retinoids or vitamin C?
Follow the exact product’s compatibility guidance. The Ordinary advises avoiding its copper-peptide serum with retinoids, direct acids and strong antioxidants such as vitamin C. That is guidance for this finished formula, not proof that every copper-peptide combination behaves identically.
Does a 4–8-week injection schedule mean a proven safe cycle?
No. The displayed range is attributed to one clinic’s webpage. It is not a clinical-trial result, a universal schedule or proof of safety, and it should not be extended using a plotter curve.
Sources Labels, studies and notes behind this guide
Catalog evidence: Human clinical trials. This describes the type of evidence, not a clinical review of every claim.
Summary and fact source checks: 2026-10-07. This records source checking, not medical review of the whole page.
Notes on the quick facts
- Why people use it
- These are cosmetic goals; the size of any improvement depends on the finished product and remains uncertain.
- Hair findings
- One small topical study reported thicker, more numerous eyebrow hairs after 12 weeks. This does not establish scalp regrowth.
- Route choice
- Topical findings cannot establish a superior cosmetic effect or suitable dose for an injection.
- 1. The Ordinary — Multi-Peptide + Copper Peptides 1%
Current first-party product page: includes GHK-Cu plus other peptides and hyaluronic acids; cosmetic goals, a few drops to the face morning/evening, unbroken skin and irritation instructions. The named 1% product is not a pure-GHK dose or proof of isolated GHK-Cu efficacy.
- 2. Wang et al., 2026 — GHK-Cu plus ferment-extract cream
Full text checked via Europe PMC XML (PMC13455814), especially sections 2.8 and 3.3: 32 adults enrolled, 30 completed; all used 5% ferment extract plus 0.2% GHK-Cu twice daily for 56 days. Several appearance measures improved, but no untreated/vehicle human control and no isolated GHK-Cu arm. Company-linked formulation study.
- 3. Bo et al., 2026 — 2% GHK-Cu eyebrow serum study
Original publication abstract: 18 adults aged 18–40, randomized double-blind split-face comparison; 2% serum on one eyebrow and vehicle on the other, twice daily for 12 weeks. Reported increased eyebrow hair count/diameter. Small preliminary report; application quantity and percent basis not stated in the abstract. Not scalp-alopecia or injection evidence.
- 4. Miller et al., 2006 — topical GHK-Cu after CO2 laser resurfacing
Original abstract checked through NCBI EFetch: 13 completers, randomized post-laser skin regimens with/without GHK-Cu; no objective group advantage in redness resolution, wrinkles or overall skin quality, despite higher patient satisfaction. Specialized post-procedure setting.
- 5. FDA — safety considerations for injectable GHK-Cu
Current route-specific GHK-Cu entry cites possible immune reactions from aggregation/peptide impurities and limited human safety data. Applies to injectable compounded drugs, not a blanket prohibition or safety finding for all topical cosmetics.
- 6. Trusta Medical Center — published GHK-Cu injection example
Clinic webpage dated 2 June 2026 states 1–2 mg daily by subcutaneous injection for 4–8 weeks followed by reassessment. Published clinic example only; no trial validates its cosmetic claims, and product concentration/formulation is not specified. Do not turn it into a common consensus, approved regimen or syringe-volume instruction.
- 7. In vivo stimulation of connective tissue accumulation by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+ in rat experimental wounds.
Legacy 0.96 h is unverified for administered-human intact GHK-Cu. No quantitative timing is imported from free-GHK degradation.
- 8. 1997 original rat GHK/HK analytical PK paper
GHK acetate given IV to rats, rapidly degraded toHK; freeGHK is not intactGHK-Cu.
Keep reading
Related compounds and examples
Related compounds
AHK-Cu
AHK-Cu for fuller-looking hair: topical product context, comparison with GHK-Cu and what the follicle study can—and cannot—show.
Glutathione
Glutathione for skin and antioxidant goals: oral study doses, injection trade-offs and why a higher blood level is not a guaranteed detox or cosmetic result.
GGH Blend
GGH is a marketed mixture of GHK-Cu, glutathione, histidine, glycine and NADH. A named seller provides component amounts, but its heading conflicts with their sum—an important distinction before treating the product name as a known strength.
Protocols featuring GHK-Cu (Copper Peptide)
Skin GLOW Stack
Comprehensive skin-and-recovery blend (GHK-Cu + TB-500 + BPC-157 + KPV) dosed daily for collagen, healing, and anti-inflammatory support. Based on the GLOW/Upgraded-Glow blend ratios.
Comprehensive Healing Blend (4-Peptide)
Long-course healing + recovery blend (TB-500 + BPC-157 + KPV + GHK-Cu) dosed daily. A 2-week intro at half dose to assess tolerance, then 10 weeks at the standard dose. Modeled on documented blend ratios.