GHK-Cu is not FDA-approved as an injectable medication. The injection protocols described below are summarized from peer-reviewed research and the dosing patterns commonly reported in the literature — they are not prescribing guidance. Topical formulations sold as cosmetics are a different regulatory category and follow product-specific instructions. Consult a licensed provider before starting any injectable peptide.
GHK-Cu — short for glycyl-L-histidyl-L-lysine copper complex — is a small, naturally-occurring tripeptide that binds a single copper ion. It's been studied since the 1970s for its effects on skin remodeling, wound healing, and hair-follicle support, and it's the most-searched cosmetic-category peptide of the past year.
This post covers what the published research actually shows, how typical injection protocols are dosed, and the reconstitution math for the 100 mg vial sizes most users encounter.
What the research describes
GHK-Cu was first isolated from human plasma in 1973. The body's natural levels decline with age. Pickart and colleagues have published the most extensive review work on the molecule — a 2018 review in the International Journal of Molecular Sciences surveys mechanisms across skin, hair, and nervous-system tissue.
The published literature describes effects in four broad categories:
- Collagen and elastin synthesis — fibroblast activation in skin-tissue models
- Wound healing — accelerated closure rates in animal and human studies, particularly for diabetic and chronic wounds
- Hair-follicle signaling — cited in studies of follicle-cell proliferation
- Anti-inflammatory and antioxidant activity — across multiple tissue types
These are mechanism-of-action findings from controlled research, not clinical claims. GHK-Cu has no FDA-approved indication.
Topical vs injection — two different products
This is the single most common source of confusion. There are two fundamentally different ways GHK-Cu is used:
| Form | What it is | Where it's sold | Dosing |
|---|---|---|---|
| Topical (cream, serum) | GHK-Cu in a cosmetic base | Skincare retailers, dermatology offices | Per the product label — typically 1–2× daily |
| Subcutaneous injection | Reconstituted lyophilized peptide | Compounding pharmacies, research suppliers | Per individual research protocol |
The topical version is what mainstream skincare brands sell. It does not require reconstitution and is regulated under cosmetic — not drug — law.
The injection version is what this site's calculator handles. It ships as a freeze-dried powder in a sealed vial that you reconstitute with bacteriostatic water before drawing each dose.
Typical injection protocols
The dose ranges and frequencies most commonly reported in the research literature for subcutaneous GHK-Cu:
| Phase | Weeks | Dose |
|---|---|---|
| Cycle (skin & hair support)Most-cited general protocol | 1–12 | 2 mg, 3× per week |
| Stack with NAD+ (Glow Stack)Companion: NAD+ 100 mg weekly | 1–8 | 2 mg, 3× per week |
These match the iOS app's "GHK-Cu — Skin & Hair" and "Glow — GHK-Cu + NAD+" templates. Cycle length varies by individual goal and provider guidance — 8 to 12 weeks is the typical reported range, after which many users take a 2–4 week break before resuming.
The reconstitution math
GHK-Cu vials most commonly ship as 100 mg lyophilized powder. Reconstituting with 5 ml of bacteriostatic water gives a stable working solution at 20 mg/ml.
For a 2 mg dose:
volume_ml = 2 mg ÷ 20 mg/ml = 0.10 ml
units = 0.10 ml × 100 (U-100 syringe) = 10 units
Punch the same numbers into the calculator below to verify against your specific vial — some suppliers use 50 mg or 200 mg vials, which change the concentration.
Inputs
GHK-Cu common vial sizes: 50 mg, 100 mg, 200 mg. Typical dose range: 1–3 mg. Research publications. Not medical advice.
for a 1 mg dose
- Concentration
- 25.0 mg/ml
- Volume
- 0.040 ml
- Per ml
- 100 u
Not medical advice. Always verify against your vial label and your provider's instructions. Re-check before drawing.
What to watch for
- Mild redness or flush at the injection site — common in the first doses, usually transient
- Slow visible change — meaningful skin or hair changes typically emerge over 4–12 weeks; baseline photos every 4 weeks are the only reliable way to assess
- Possible darkening of existing moles or freckles — copper-related, reported in a minority of users; bring this up with your provider
- Storage matters — reconstituted vials are typically refrigerated at 36–46°F (2–8°C) and used within 2–3 weeks
If you have a confirmed copper sensitivity, Wilson disease, or any condition that affects copper metabolism, do not use GHK-Cu without explicit clearance from your provider. The copper-binding mechanism is fundamental to how the peptide works.
Tracking a GHK-Cu protocol
The iOS app handles the practical layer:
- Auto-advance the 12-week cycle
- 3-times-weekly reminders (default Mon / Wed / Fri)
- Body-map injection-site rotation so you don't reuse the same spot
- Photo log for tracking visible change over the cycle
- Doctor-ready PDF export
Related reading
- GHK-Cu reference page — common vial sizes and dose ranges
- The Glow Stack: GHK-Cu + NAD+ — why some users pair the two
- Resources page — where the dosing data on this site comes from
References
- Pickart L. & Margolina A. Int J Mol Sci 2018 — comprehensive mechanism review
- PubMed: GHK-Cu — full literature
- ClinicalTrials.gov: GHK-Cu — active and completed trials