TCW illustrated field note · 17
GHK-Cu: route changes the question
Read skin-care claims and injection claims separately.
The guide, in text
What the name means
GHK-Cu is the copper complex of the tripeptide glycyl-histidyl-lysine.
Check the formulation
A serum, cream and injectable preparation are different products.
Match evidence to the claim
Ask whether the study tested the same route, concentration and outcome.
Injection uncertainty
FDA notes limited human safety data and potential immune reactions with injectable GHK-Cu.
Avoid borrowed protocols
Topical research does not establish an injectable dose, cycle, combination or beyond-use date.
Sources + context
Source review: September 2026. Illustrations explain concepts; they do not verify products or replace individualized advice.