GHK
Also known as: Glycyl-L-Histidyl-L-Lysine, GHK Tripeptide
A naturally occurring tripeptide (three amino acids: glycine, histidine, lysine) found in human plasma, saliva, and urine. Levels decline sharply with age. Even without copper binding, GHK has demonstrated wound healing, collagen stimulation, and gene expression effects in research.
How it works
GHK is a small tripeptide that naturally circulates in your blood at around 200 ng/mL when you are young, dropping to under 80 ng/mL by age 60. Research shows it can influence the expression of over 4,000 human genes involved in tissue remodeling, collagen production, antioxidant defense, and inflammation control. Even without copper, GHK promotes fibroblast activity, accelerates wound closure, and signals for new collagen and elastin production.
Common uses
- Skin rejuvenation and anti-aging
- Wound healing support
- Collagen and elastin stimulation
- Hair growth support
- Gene expression modulation
Side effects
- Very well-tolerated topically
- Rare mild skin irritation
- Injectable forms may cause injection site reactions
- No significant adverse effects reported in published research
Key research
- Gene expression studies show GHK modulates over 4,000 human genes related to tissue repair and anti-aging
- Plasma levels decline from 200 ng/mL at age 20 to under 80 ng/mL by age 60
- 2025 clinical trial of 21 women showed 28% average increase in collagen density after 3 months of daily GHK-Cu application
- Double-blind study of 60 participants showed 22% increase in skin firmness and 16% reduction in fine lines over 12 weeks
Safety notes
- GHK-Cu (copper-bound form) is the most commonly used and studied version
- Topical GHK-Cu is Category 1, meaning it can be compounded by pharmacies
- No injectable formulations are FDA-approved
- Widely available in over-the-counter skincare products
- The copper-bound form (GHK-Cu) has more clinical data than the base tripeptide alone
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