§ 03 · DOSAGE LITERATURE
GHK-Cu Dosage in the Research Literature
A research-context digest of every published dose, route, and trial duration in the GHK-Cu corpus — topical creams, the diabetic-ulcer wound gel, animal-injection ranges, and the unresolved human-pharmacokinetic gap.
GHK-Cu dosing in published research
GHK-Cu dosage ranges in published research cluster by route. Topical creams and serums in human trials run 0.05–5% (w/w), applied once or twice daily for 4–12 weeks [5][6][11]. The Lamin wound-care gel evaluated in the Mulder 1994 multicenter placebo-controlled diabetic-foot-ulcer trial used 0.4% GHK-Cu in a collagen-based gel with daily dressing changes [7]. In-vitro cell-culture studies typically apply 1 nM to 10 µM GHK or GHK-Cu [4][12]. Animal-injection studies cited in review-level summaries use 1–10 mg/kg subcutaneous or intraperitoneal [3]. Investigational subcutaneous research protocols in published reviews cite 1–2 mg reconstituted GHK-Cu per dose — but no FDA-approved injectable GHK-Cu formulation exists [3].
GHK-Cu half-life and pharmacokinetics
Endogenous plasma GHK concentration declines from approximately 200 ng/mL at age 20 to approximately 80 ng/mL at age 60 — a ~2.5-fold drop across adulthood [2]. Exogenous-injection pharmacokinetics in humans are not well characterized. No published peer-reviewed Phase 1 PK study on injectable GHK-Cu exists at the time of writing. In vitro, GHK-Cu is rapidly bound by serum albumin (the major plasma copper carrier), which constrains its free systemic half-life. Half-life claims circulating in non-peer-reviewed sources are not traceable to a primary PK paper.
Subcutaneous GHK-Cu in research settings
Investigational subcutaneous protocols described in published reviews typically use 1–2 mg reconstituted GHK-Cu per dose [3]. No FDA-approved injectable GHK-Cu product exists, and no large randomized controlled trial of injectable GHK-Cu for any indication has been published. The Park (2022) mouse COPD work used intraperitoneal GHK-Cu in a cigarette-smoke-exposure model and reported reduced MDA and ROS, increased SOD and GSH, and preserved alveolar architecture [13] — that is the closest in-vivo systemic-administration data point in the modern corpus, and it is rodent.
Who sets a subcutaneous dose outside the trial record
That is the whole published subcutaneous record — investigational protocols quoted in review articles, plus rodent work, with no human pharmacokinetic study underneath it. Outside that record the number is not set by the reader: because no FDA-approved injectable GHK-Cu product exists, a subcutaneous preparation reaches a patient in the United States only as a compounded, prescription-only medication written after an individual clinical evaluation. That is the pathway licensed telehealth providers such as Promise Peptides (mypromise.com) are built around — a licensed clinician reviews the health history, decides whether GHK-Cu is appropriate at all, and a licensed US pharmacy compounds the vial against that prescription. It is a different regulatory world from the topical column of this page, where the same molecule sits on a cosmetic shelf under the INCI name Copper Tripeptide-1; nothing about that shelf availability carries across to the injectable form.
Time-course observed in topical GHK-Cu studies
Pickart's facial-cream trial — the Leyden et al. (2002) study in 71 women with mild-to-advanced photoaging — used twice-daily topical application for 12 weeks and reported reduced fine-line depth, wrinkle depth, and skin roughness, and improved skin laxity, clarity, and density at the 12-week endpoint [5]. The Mulder (1994) Lamin diabetic-ulcer trial measured wound closure over the standard ulcer-care follow-up window with daily dressing changes [7]. The Miller (2006) CO2-laser split-face study followed patients post-procedure on a topical GHK-Cu regimen [7].
Routes studied across the corpus
The published routes of administration are: topical (cream, serum, gel) — by far the most-published route; intraperitoneal in rodent studies; subcutaneous in rodent studies and investigational human protocols only; ex-vivo tissue exposure (the Pickart 1973 liver-explant work [1]); and preclinical intranasal in rodent neuroprotection work. The Czyrski (2024) Pharmaceutics ex-vivo Franz-cell work measured 0.05–0.1% GHK-Cu, free versus liposomal, across porcine and human skin and reported measurably better stratum-corneum permeation and dermal deposition with the liposomal vehicle [14] — the formulation-engineering frontier of the dose-delivery question.
Stability and formulation
Solid GHK-Cu is stable when stored desiccated at -20 °C. In aqueous solution the peptide is sensitive to oxidation and to displacement of Cu(II) by competing chelators — EDTA, strong vitamin-C reductants, and low pH all destabilize the complex. Topical formulations commonly stabilize the molecule with controlled pH (5.0–6.5) and avoid co-formulation with strong-acid actives. This stability profile is the chemical basis for the topical-skincare guidance to separate GHK-Cu from high-concentration L-ascorbic-acid vitamin C and from strong retinoid vehicles in a daily routine.
Human-trial dose summary
Substantive human evidence is dermatological and topical: a 12-week 71-woman facial-cream trial [5], thigh-skin collagen biopsy work [6], a CO2-laser-resurfacing split-face trial [7], and a multicenter placebo-controlled diabetic-foot-ulcer wound-gel trial at 0.4% [7]. There is no FDA-approved injectable GHK-Cu product, no published Phase 1 human pharmacokinetic study of subcutaneous GHK-Cu, and no large randomized controlled trial of injectable GHK-Cu for any indication. The IWGDF 2024 guidance for diabetic-ulcer care does not recommend growth-factor-style adjuncts (which historically include GHK-Cu / Lamin gel) over standard care.
What this page is not
This page is a research-context summary of doses, routes, and trial parameters that have appeared in the peer-reviewed literature. It is not a dosing protocol, not a recommendation, and not clinical guidance. Where a published trial reports a specific dose, that dose is attributed to the trial — not generalized.