News

GHK-Cu Dosage: How Prescribers Set the Amount

Creator: Nadia Okonjo, Health Writer
Published: 2026-09-02

There is no validated human injection dose for GHK-Cu. Topical studies disclose several concentrations, while compounded injection amounts come from clinical practice and must be tied to the exact vial and the person being treated.

Nadia Okonjo, Health Writer September 2, 2026 6 min read

A woman folds a cream towel in a quiet sunlit spa room

The short version

No human dose-finding trial has established an injected GHK-Cu dose; the commonly described 1–2 mg range is a clinical-practice convention, not a validated target.
Topical human studies have included 2% and 4% wound gels and a 0.2% GHK-Cu combination face cream, but those formulations and purposes cannot be converted into an injection dose.
One milligram of the idealized GHK-Cu complex contains about 158 micrograms of copper; 2 mg contains about 315 micrograms, versus the 900-microgram adult dietary RDA.
Dietary copper guidance is context, not an injectable safety ceiling, because injection bypasses intestinal absorption and regulation.
KLOW uses a fixed ratio of GHK-Cu, BPC-157, TB-500 and KPV, so changing the blend volume changes exposure to every component at once.
GHK-Cu is dispensed as a compounded medication, which is different from an FDA-approved product: the formulation offered here is not FDA-approved.

GHK-Cu dosage is route-specific, and no human trial has established a dose for injected GHK-Cu. Human topical work has tested concentrations from 0.2% in a combination face cream to 2% and 4% in wound gels, but those products, skin conditions and endpoints are not interchangeable. Compounded injection protocols often describe low-milligram amounts, commonly 1–2 mg per injection, yet that range comes from clinical practice rather than a dose-finding trial. The prescribed amount therefore depends on the route, vial concentration, copper exposure, medical history and whether GHK-Cu is used alone or in a fixed-ratio blend.

The GHK-Cu evidence overview owns the broader mechanism and outcome question. This page stays with how the number is chosen; GHK-Cu side effects by route covers tolerability in detail.

What a GHK-Cu dosage number actually describes

A percentage on a topical product and a milligram amount on an injection prescription answer different questions. Topical strength describes how much ingredient is present in the finished cream or gel. It does not say how much crosses the skin. An injectable prescription has to connect the amount of GHK-Cu in milligrams with the vial concentration in milligrams per milliliter and the interval chosen by the prescriber.

Number	What it means	What it does not decide
Topical percentage	Ingredient mass relative to the finished formulation; 0.2% w/w is 2 mg per gram	Skin penetration or an injectable amount
Amount per injection	The prescribed mass of GHK-Cu	The liquid volume without the vial concentration
Vial concentration	How many milligrams are present per milliliter	How often an injection is prescribed
Interval and duration	How exposure accumulates over time	Whether a higher amount is appropriate

Promise's GHK-Cu vial is labeled 10 mg/mL. At that concentration, 1 mg is contained in 0.1 mL and 2 mg in 0.2 mL. That is concentration arithmetic, not a suggested dose or a direction to self-administer. A differently concentrated vial would require different volume arithmetic for the same prescribed amount.

Topical GHK-Cu dosage in human studies

There is no single clinically established topical concentration. The disclosed numbers come from studies with different formulations, populations and purposes.

Study	Topical formulation studied	What the number can establish
Mulder et al., 1994	2% GHK-Cu gel versus vehicle after debridement; a second component compared 2% and 4% gels	These concentrations were studied in diabetic neuropathic ulcers, not routine facial skin (Wound Repair and Regeneration 1994)
Wang et al., 2026	0.2% GHK-Cu plus 5% mixed-culture ferment cream, twice daily for 56 days; 32 adults enrolled and 30 completed	The study tested a combination without a vehicle-control arm, so it cannot isolate GHK-Cu or define an optimal concentration (Skin Research and Technology 2026)
Hostynek et al., 2011	0.68% aqueous copper tripeptide over 48 hours	This was a diffusion-cell experiment on isolated human skin, not treatment of participants (Inflammation Research 2011)
Older facial studies	GHK-Cu creams used twice daily for 12 weeks in groups of 71 and 67 women	The peer-reviewed summary reports the schedules and findings but not the proprietary concentrations (Gorouhi and Maibach, 2009)

The practical lesson is not that 4% is four times better than 1%. Vehicle, stability, the chemical form of the complex, application area and skin barrier all affect exposure. A percentage copied from a wound gel cannot be treated as a dose-finding result for a cosmetic cream.

Injectable GHK-Cu has a practice range, not a trial dose

No published human dose-finding trial has compared injected GHK-Cu amounts for pharmacokinetics, clinical response or long-term copper balance. A 2025 review likewise found that even the topical anti-wrinkle literature lacks the concentration and permeability work needed to define an optimum (Mortazavi et al., BioImpacts 2025).

Compounded protocols commonly describe about 1–2 mg per injection. Some use a daily interval; others use several injections per week or a defined course. That variation is evidence of an unsettled practice pattern, not a menu from which a patient should select. The prescriber has to connect any amount with the actual concentration, requested use, treatment duration, other sources of copper, prior injection reactions and the reason for reassessment. The guide to peptide injection frequency explains why amount and interval are separate decisions.

KLOW changes every ingredient at once

KLOW contains GHK-Cu with BPC-157, TB-500 and KPV in one fixed-ratio compounded vial. The prescriber chooses an amount of the finished blend; GHK-Cu cannot be raised or lowered independently inside that vial. Increasing its volume increases exposure to all four components, and reducing it lowers all four.

That makes a single-compound GHK-Cu protocol and a KLOW protocol different calculations. Adding a GHK-Cu practice amount to numbers taken from unrelated component studies does not create a blend dose. The KLOW peptide dosage guide explains the fixed-ratio constraint without turning it into a self-dosing chart.

How much copper is in a typical GHK-Cu amount?

GHK-Cu is a one-to-one copper-peptide complex with a molecular mass of about 402.9 grams per mole. Copper's atomic mass is 63.546, so copper is about 15.8% of the complex by mass. The arithmetic for the practice range is:

GHK-Cu amount	Approximate elemental copper	Share of the 900 microgram adult dietary RDA
1 mg	158 micrograms	18%
2 mg	315 micrograms	35%

The molecular-mass figure is summarized in a peer-reviewed formulation review, and the adult copper RDA is 900 micrograms per day (Mortazavi et al., BioImpacts 2025; Burkhead and Collins, Advances in Nutrition 2022). The exact copper content of a dispensed preparation remains tied to its labeled chemical form.

This comparison is context, not a safety ceiling for injection. The RDA was developed for copper eaten over a day, with intestinal absorption and regulation in the path. An injection bypasses that route. Food, supplements, liver function and disorders of copper handling can all change how a prescriber reads the same arithmetic.

Why the prescriber sets the amount

As of August 2026, the FDA's 503A bulk-substances document places non-injectable GHK-Cu in Category 1 under evaluation and notes that the injectable-route nomination was withdrawn; that status is not a dose recommendation (FDA, May 14, 2026). Promise dispenses GHK-Cu as a compounded medication, which is different from an FDA-approved product: the formulation offered here is not FDA-approved. A licensed provider may still prescribe a compounded formulation when they judge it clinically appropriate; that decision is between the patient and the doctor.

At Promise, a licensed provider reviews every request, and not everyone qualifies. The review weighs the exact formulation and concentration, copper-related conditions and supplements, liver and biliary history, current medications, pregnancy or breastfeeding, and what follow-up can measure. Without a validated blood target or injection dose-response curve, changing the amount is a clinical judgment rather than movement up a universal ladder.

A usable prescription states the milligram amount, the labeled concentration, the resulting volume, the interval, the course length and the point for reassessment. If any one of those is missing, a number found online cannot fill the gap.

Common questions

What is a typical GHK-Cu injection dosage?

Compounded protocols commonly describe about 1–2 mg per injection, but no human dose-finding trial has validated that range. Published schedules also differ, from daily use to several injections per week or a defined course. Those numbers describe practice patterns, not instructions. A prescriber sets the amount, interval and duration from the exact formulation, concentration, medical history and follow-up plan.

What concentration of topical GHK-Cu has been studied?

Human research has used several concentrations rather than one standard. Published work includes 2% and 4% wound gels and a 0.2% GHK-Cu face cream that also contained 5% mixed-culture ferment. Older 12-week facial studies reported their schedules but not the proprietary GHK-Cu concentration. These formulations and purposes differ, so their percentages are not interchangeable.

How much copper is in 1 mg of GHK-Cu?

One milligram of the idealized one-to-one GHK-Cu complex contains about 158 micrograms of elemental copper. That is roughly 18% of the adult dietary RDA of 900 micrograms. The comparison provides scale, not an injectable safety limit: dietary guidance assumes oral intake and intestinal regulation, while an injection bypasses the gut, and the dispensed chemical form also matters.

Is GHK-Cu dosage the same in KLOW?

No. KLOW is a fixed-ratio compounded blend of GHK-Cu, BPC-157, TB-500 and KPV. The prescriber chooses an amount of the finished blend, and any volume change moves exposure to all four components together. A single-compound GHK-Cu amount cannot simply be inserted into the blend or adjusted independently without changing the formulation.

Who sets a compounded GHK-Cu dose?

The prescribing clinician sets it after reviewing the exact formulation, vial concentration, requested use, medical history, current medications and supplements, and copper-related considerations. The prescription must connect milligrams with volume, interval and course length. Follow-up determines whether the plan stays the same, changes or stops; a general chart cannot make those patient-specific decisions.

Does a higher topical percentage mean a stronger clinical effect?

Not necessarily. A percentage states how much GHK-Cu is in the finished product, not how much remains stable or crosses the skin. Vehicle, chemical form, application area and skin-barrier condition all affect exposure. The clinical studies also tested different products for different purposes, so their percentages do not form a simple low-to-high effectiveness ladder.