GHK-Cu Dosage Chart & Schedule Guide.

No. Prezatide copper acetate (marketed as Iamin by ProCyte) was investigated as a wound-healing drug and never reached approval. Between September 2023 and April 2026 the FDA listed "GHK-Cu (except for injectable routes of administration)" in Category 1 of the interim 503A bulks list, while placing injectable GHK-Cu in Category 2 for significant safety risks. On 15 April 2026 both entries came off the list: the non-injectable form was removed from Category 1 and the injectable form separately removed from Category 2, in both cases because the nominators withdrew their nominations. Removal from Category 2 does not make a substance eligible for compounding, and removal from Category 1 means topical GHK-Cu no longer has that pathway either. Both are slated for Pharmacy Compounding Advisory Committee consultation before the end of February 2027. Until then, compounding pharmacies cannot legally supply injectable GHK-Cu, and material sold online is research-use-only.

Topical, if your goal is skin or hair. That is not a hedge, it is where the evidence is: the randomised diabetic-ulcer trial used a 2% gel, and the 12-week facial, eye and thigh studies were topical as well, though none of those three reported the GHK-Cu concentration they used, so no trial-backed strength can be quoted for them. For scale, cosmetic preparations generally run 0.2 – 2%, and the 0.2 – 3% you see quoted is anecdotal compounding practice for alopecia rather than a studied dose. Injection has one human study behind it and that one delivered the drug into an ulcer, not systemically. The theoretical case for injecting is systemic delivery for internal repair and gene modulation: plausible from the animal work, unvalidated in people. Many users do both: a daily topical for the skin, a cycled injectable for systemic goals.

GHK-Cu is roughly 15.8% copper by weight (molar mass about 402 g/mol, of which copper is 63.5). So 1 mg delivers about 158 mcg of copper, and 2 mg about 316 mcg. For scale, the oral RDA for copper is 900 mcg/day and the tolerable upper limit is 10 mg/day. Those oral numbers are not directly transferable, though, and that is the point: dietary copper absorption is actively regulated by the gut, and injecting bypasses that gate entirely. At 1 – 2 mg/day the load is modest. It is the people running 5 – 10 mg daily for months who are in genuinely uncharted territory, and there is no published safety ceiling for this route to reassure them.

The copper ion. GHK-Cu is one of the most consistently reported peptides for injection-site reactions, and copper is a recognised mast-cell trigger. Concentration is the main lever: reconstituting a 50 mg vial in 5 mL gives 10 mg/mL, which stings far less than the 25 mg/mL you get from the common 50 mg-in-2 mL mix. If it still bites, add more bacteriostatic water and inject a larger volume, inject slowly, let the solution reach room temperature first, and rotate sites. Persistent lumps past 48 hours mean back off the concentration, not push through it.

Yes, faintly blue or blue-green. GHK-Cu is naturally blue because of the bound copper(II), and the powder itself carries that colour. A solution that reconstitutes completely clear and colourless is a red flag: it suggests plain GHK with little or no copper, which is a different (and cheaper) molecule with a different profile. On the other end, a deep or dark blue solution, visible particles, or anything cloudy also means something is wrong. One nuance worth knowing: at the 0.2 – 2% concentrations typical of topical preparations, GHK-Cu is not generally noted to stain skin, so the colour itself is not a problem.

The hair evidence is real, but it is neither injectable evidence nor, read carefully, GHK-Cu evidence. The study everyone cites (Pyo and colleagues, Archives of Pharmacal Research, 2007) tested AHK-Cu (alanyl-histidyl-lysine copper), a different tripeptide, and found follicle elongation ex vivo and dermal papilla cell proliferation at 10⁻¹² to 10⁻⁹ M, extraordinarily low concentrations. There is no equivalent ex vivo human hair-follicle study for GHK-Cu itself, at any concentration. Proposed mechanisms for copper peptides generally include fibroblast proliferation and suppression of TGF-β1, which is overexpressed in hereditary hair loss. Compounders use 0.2 – 3% GHK-Cu topically for alopecia, a range that is anecdotal practice rather than a trial concentration. What does not exist is any randomised trial of subcutaneous GHK-Cu for hair, at any dose. It is not in the same evidence class as finasteride or minoxidil and should not be substituted for them.

The 4-weeks-on/4-weeks-off convention is not derived from any trial; no study has run injectable GHK-Cu long enough to find out. It exists for one defensible reason: copper accumulates, injected copper bypasses intestinal regulation, and copper excess specifically impairs zinc-dependent processes. Cycling caps cumulative exposure while the long-term data does not exist. If you would rather run continuously, the sensible version is the three-times-weekly maintenance tier plus periodic serum copper, ceruloplasmin and zinc (actual numbers instead of a calendar rule).

Keep the lyophilised powder cold (2 – 8 °C) and out of light; it is more robust than most peptides: one stability assessment found GHK-Cu stable in water at pH 4.5 – 7.4 held at 60 °C for at least two weeks, and it dissolves readily, with reported solubility up to around 325 mg/mL. Once reconstituted with bacteriostatic water, refrigerate and use within roughly 28 days, which is a limit set by the benzyl alcohol preservative rather than by the peptide. Do not freeze a reconstituted vial, do not shake it (swirl instead), and discard it if the blue tint disappears, deepens noticeably, or anything visible forms in the solution.