Peptide Skincare & BeautySkin science and ingredient guides

Ingredient or product comparison

Comparison Table: GHK-Cu Delivery Methods for Age 40–49

Subcutaneous injection (1–2mg daily) 15–25 ng/mL within 45 minutes Systemic. Reaches papillary and reticular dermis via circulation 23% increase measured by ultrasound Daily Gold standard for age 40+. Only method achieving therapeutic plasma levels for fibrobl

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  • Subcutaneous injection (1–2mg daily)
  • 15–25 ng/mL within 45 minutes
  • Systemic. Reaches papillary and reticular dermis via circulation
  • 23% increase measured by ultrasound
  • Daily
  • Gold standard for age 40+. Only method achieving therapeutic plasma levels for fibroblast activation
  • Topical 2% GHK-Cu serum
  • Unmeasurable in plasma
  • 5–8 micrometres (stratum corneum only)
  • 6% increase (surface epidermis only)
  • Twice daily
  • Cosmetic-grade only. Does not reach dermal fibroblasts where age-related thinning occurs
  • Microneedling + topical GHK-Cu
  • Trace plasma levels (inconsistent)
  • 200–500 micrometres (needle depth dependent)
  • 14% increase (localised to treated areas)
  • Weekly with 7-day recovery
  • Moderate efficacy. Enhances penetration but trauma-induced inflammation may degrade peptides before absorption
  • Oral GHK-Cu capsules
  • Negligible (peptides degraded in gastric acid)
  • None. Systemic circulation not achieved
  • No measurable effect
  • Ineffective. Tripeptides are cleaved by pepsin before intestinal absorption