What is the difference between topical GHK-Cu and other forms of use?
Updated: 2026-09-09 · GHK-Cu, skin and hair
Short answer
Topical use puts the product at the skin surface, and it is the route with the most accumulated cosmetic experience. That is not the same as guaranteed delivery: actual penetration and bioavailability depend heavily on the formulation and on the state of the skin barrier. Non-topical routes have much less human evidence and raise different safety questions.
In plain English
- Topical: local target, established cosmetic use.
- Systemic: less data, more uncertainty.
- Concentration and formulation can materially affect how much of the product is delivered.
What we know
- Topical cosmetic use is the context with the most accumulated experience.
What we don't know yet
- Benefit and safety of non-topical routes in humans are not established.
- How much GHK-Cu actually crosses the skin barrier depends on the formulation and is not well characterised.
Sources
External links to official sources or peer-reviewed studies.