GHK-Cu Dosing Guide
A daily 1–2 mg copper peptide, cycled because copper adds up.
GHK-Cu is the copper peptide, used for skin, hair and general tissue quality. Injected doses are a milligram or two a day. Two things set it apart: the solution is naturally blue, and it is the peptide most likely to sting — so how much water you mix it with is a comfort decision, not just a math one. Topical creams are a separate, lower-dose use.
At a glance
- Typical dose
- 1–2 mg per injection (start at 1 mg/day, work up to 2 mg)
- How often
- Once a day; 5 days on / 2 off and 3× a week are common alternatives
- Route
- Subcutaneous — abdomen, outer thigh, back of the arm
- Timing
- No consensus; evening and morning both cited
- How long
- 4–8 weeks on, 2–4 weeks off
- Vial sizes
- 50 mg and 100 mg
How much
The consensus injected dose is 1 to 2 mg per shot. Most guides start at 1 mg a day and move to 2 mg after a couple of weeks. The full range across sources is roughly 0.2 mg (a cautious start) up to 3 mg a day, with a few wound-healing protocols splitting up to 4 mg a day into two shots.
For topical use the conventions are different: 1–3% creams or serums, applied once or twice a day for 8–12 weeks on the face, or daily for 12+ weeks on the scalp.
How often & when
Once daily is the most common. Alternatives that show up repeatedly: 5 days on / 2 days off; 2 mg three times a week (Mon/Wed/Fri); and a maintenance pattern of 1 mg every other day.
Injections are subcutaneous and systemic — abdomen, outer thigh or back of the upper arm. GHK-Cu stings more than most peptides and can leave a blue-tinted bruise, so inject slowly and rotate sites. There is no agreement on time of day.
How long
Most sources cite 4–8 weeks on followed by 2–4 weeks off; 30 days on / 30 days off and 8–12 weeks on / 4 off also appear. The reason for cycling is copper: every milligram of GHK-Cu delivers copper, and the sources treat the cumulative load as the thing to manage.
Several guides describe an escalation rather than a loading phase — 1 mg a day for the first two weeks, then 2 mg — or a slower 1.0 → 1.5 → 2.0 mg ramp over 12 weeks.
Mixing the vial
Doses below are for a standard U-100 insulin syringe (100 units = 1 mL). The formula: units = dose in mg ÷ concentration in mg/mL × 100. Bacteriostatic water is the usual diluent. A standard peptide vial holds about 3 mL of liquid at most — the store’s vials included — so every row below stays at or under 3 mL. Guides elsewhere that call for 4–5 mL will not fit.
| Vial | Water added | Concentration | Doses in units |
|---|---|---|---|
| 50 mg | 2 mL | 25 mg/mL | 1 mg = 4 units · 2 mg = 8 units · ~50 doses of 1 mg |
| 50 mg | 3 mL | 16.7 mg/mL | 1 mg = 6 units · 2 mg = 12 units (more dilute = less sting) |
| 100 mg | 2 mL | 50 mg/mL | 1 mg = 2 units · 2 mg = 4 units |
| 100 mg | 3 mL | 33.3 mg/mL | 1 mg = 3 units · 2 mg = 6 units |
GHK-Cu has the most variable mixing conventions of any peptide. More water means a more comfortable injection and easier-to-read units — many people dilute more for exactly that reason. Some guides online go to 4–5 mL, but a standard vial holds about 3 mL at most, so 3 mL is the practical ceiling.
How to reconstitute
Not sure how to mix the vial? Our free Reconstitution Calculator walks you through it: enter the vial size, how much bacteriostatic water you're adding and the amount you want per dose, pick your syringe, and it tells you exactly what mark to draw to, the concentration, and how many doses the vial holds — with a syringe diagram and a step-by-step worked example.
Practical tips
- A blue solution is normal. Refrigerate, keep it out of light, and use within about 4 weeks; discard if it turns cloudy or has particles.
- Stinging, redness and blue bruising at the site are the most common complaints. Diluting more, injecting slowly and rotating sites all help.
- Copper accumulates — this is the reason every guide cycles it. Do not skip the off-weeks.
- GHK-Cu is the largest component of the GLOW and KLOW blends; if you use one of those, the blend guide covers the math.
What the evidence looks like
Evidence level
The human evidence for GHK-Cu is for topical use — controlled cosmetic trials on collagen and wrinkles. There is no published human trial of injected GHK-Cu; the injected doses here are community convention built on the topical work and on preclinical data.
For what the compound is and how it is studied — mechanism, research history and the primary literature — read the reference entry: GHK-Cu.
Batch-tested with published COAs
GHK-Cu on the store
Every vial is tested by an independent lab, with a batch-linked certificate of analysis you can check before you buy. This page is educational; purchasing happens on the store.
Common questions
Why does GHK-Cu sting?
The copper complex is irritating to tissue. Most people manage it by mixing with more water (a 25 mg/mL or lower concentration), injecting slowly and rotating sites.
Is the blue color a problem?
No — GHK-Cu solution is naturally blue. Cloudiness or particles are the signs to discard.
How much is 1 mg on a syringe?
It depends on how you mixed it: 4 units at 25 mg/mL (50 mg + 2 mL), 2 units at 50 mg/mL (100 mg + 2 mL), 6 units at 16.7 mg/mL (50 mg + 3 mL).
Sources
The figures above were compiled from the following pages. Where an FDA label exists it is listed first; the rest are vendor, clinic and community dosing references, which are not peer-reviewed.
- Peptide Dosing Protocols — GHK-Cu — 1–2 mg/day ramp over 4–8 weeks, 2–4 off; 50 mg + 2 mL = 25 mg/mL; topical 1–3% Open
- BHR Center — GHK-Cu protocol guide — 1 mg/day days 1–15 then 2 mg/day; 30 on/30 off; 0.5–3 mg/day range Open
- Peptide Deck — GHK-Cu dosage guide — 1–2 mg once daily; 8–12 weeks on, 4 off; 100 mg + 2 mL = 50 mg/mL Open
- Peptide Dosages — GHK-Cu 50 mg vial — 1.0 → 1.5 → 2.0 mg, 5 days/week, or 2 mg Mon/Wed/Fri Open
- PS Peptides — GHK-Cu dosage guide — 1–2 mg per administration; dilute-mix conventions; topical conventions Open