Amounts from tests
GHK-Cu dosage findings aren't personal directions
A cream and a shot expose your body differently. Research used amounts chosen for each test. Those amounts can't give you a safe personal-use plan.
GHK-Cu dosage numbers describe tests, not safe human use
A cream's strength can't tell you a safe injection amount. GHK-Cu dosage studies tested animals and cells in dishes. You can't read those amounts as personal doses. Very small amounts made lab skin cells increase collagen output [1]. Creams, gels and serums, thin liquid skin products, were tested at up to about 2% by weight. The percentage is the compound's share of the mixture's total weight. Your amount to apply isn't established by that percentage.
Mouse studies used different ways to give the compound. Lung and lung-scarring tests used shots into the belly. Gut-inflammation tests used a tube to put liquid in the stomach. Aging and memory tests used the nose. The human hair comparison used a scalp liquid with 50–100 milligrams of GHK per milliliter [4]. Milligrams are tiny weights, with a thousand making a gram. Milliliters measure small liquid amounts. Each result belongs to that substance, test and way of giving it.
Those separate tests can't supply a dependable human dose or schedule.
Human tests haven't established when GHK-Cu leaves the body
You don't know how quickly the human body gets rid of GHK-Cu. In a rat study, researchers injected the chain alone into a vein. GHK quickly broke into a shorter chain [11]. Other papers describe removal over roughly one to two hours. Adding copper makes GHK-Cu more stable than the bare chain. Neither fact gives you a safe shot timetable.
Material on skin behaves differently from material in blood. Lab skin retained about 97 micrograms of copper over 48 hours per square centimeter, a square roughly a fingernail wide [5]. A microgram is very light; a million micrograms make a gram. The retained copper stayed near the treated spot. You need tests of human blood to answer when GHK-Cu leaves the body after a shot, because copper staying near a treated skin patch cannot answer that different question. Schedules described by people trying research shots lack published human tests of how quickly GHK-Cu leaves blood.
Your body's handling of a shot remains an unanswered question.
Mild acidity helped GHK-Cu keep copper attached
The copper bond is strong, but can break. GHK-Cu was most stable around pH 5–6.5, a mildly acidic range on the scale that measures acidity [6]. At the tested 1:1 ratio, the mixture had equal numbers of copper particles and peptide chains. That was the balance between the two parts, not a personal mixing instruction. An intact liquid is blue-violet. Breakdown or material leaving the liquid can turn the color brown or green. Your eyes can't fully check the contents.
Strong acidity in vitamin C products can break the bond holding copper. Other acidic skin ingredients can disrupt GHK-Cu or bind its copper. GHK alone mixes easily with water and gets through skin poorly. Researchers tried tiny fat shells, special liquids, a fatty part attached to GHK, or tiny skin needles used first [14]. These were ways to study skin entry. They don't establish safe product combinations for you.
The whole tested mixture matters, including how the copper stays attached.