GHK
Also known as: Glycyl-Histidyl-Lysine, GHK Tripeptide, Liver Cell Growth Factor
GHK (Glycyl-Histidyl-Lysine) is a naturally occurring tripeptide found in human plasma, saliva, and urine. It is the parent molecule of GHK-Cu and Pal-GHK, and has been shown to modulate over 4,000 human genes; broadly resetting gene expression toward a healthier, younger pattern.
GHK is a 340.38 Da research peptide. GHK (Glycyl-Histidyl-Lysine) is a naturally occurring tripeptide found in human plasma, saliva, and urine. It is the parent molecule of GHK-Cu and Pal-GHK, and has been shown to modulate over 4,000 human genes; broadly resetting gene expression toward a healthier, younger pattern.
Also called: Glycyl-Histidyl-Lysine, GHK Tripeptide, Liver Cell Growth Factor
340.38
Molecular Weight
Daltons
3
Strong Evidence
benefits
5
Studies Cited
peer-reviewed
200-500
Typical Dose
mcg
Overview
GHK (Glycyl-Histidyl-Lysine) is a naturally occurring tripeptide first isolated from human plasma in 1973 by Loren Pickart, who discovered it as a factor in human albumin that caused aged liver tissue to synthesize proteins like young tissue. GHK is found in plasma at approximately 200 ng/mL in young adults, declining to around 80 ng/mL by age 60, a 60% reduction that correlates with declining tissue repair capacity. GHK is the parent molecule from which two major derivatives are made: GHK-Cu (copper-bound form for wound healing and injectable use) and Pal-GHK (palmitoylated form for topical skincare). While its derivatives have specific optimized applications, native GHK itself has notable biological activity. Connectivity Map analysis (using the Broad Institute's gene expression database) revealed GHK modulates the expression of over 4,000 human genes — approximately 31.2% of the human genome, with a pattern that broadly reverses age-related gene expression changes. It upregulates genes involved in tissue repair, antioxidant defense, and ECM remodeling while downregulating genes involved in inflammation, fibrosis, and tissue destruction. This makes GHK one of the most broadly active naturally occurring tissue-repair molecules known.
Key Takeaways: GHK
- Strongest evidence supports GHK for massive gene expression modulation and collagen and ecm stimulation
- Research doses typically range from 200 to 500 mcg via subcutaneous injection
- 3 benefits with strong evidence, 3 moderate, 0 preliminary
- Half-life: Minutes in plasma (rapidly binds copper and proteins)
- 5 cited research studies in this guide
Mechanism of Action
GHK has a strong natural affinity for copper(II) ions, and much of its biological activity is mediated through copper delivery to cells and copper-dependent enzyme activation. However, GHK also has copper-independent signaling activity. As a copper carrier, GHK delivers Cu(II) to cells, activating copper-dependent enzymes including superoxide dismutase (SOD, antioxidant), lysyl oxidase (collagen/elastin cross-linking), cytochrome c oxidase (mitochondrial energy), and tyrosinase (melanin synthesis). Through gene expression modulation (documented by Connectivity Map analysis), GHK upregulates collagen I/III, decorin, VEGF, FGF, and nerve growth factor while downregulating inflammatory cytokines (IL-6, TNF-α), metalloproteinases (MMP-1, MMP-9), and pro-fibrotic markers. GHK activates the ubiquitin/proteasome system for removal of damaged proteins. It modulates TGF-β signaling in a context-dependent manner; promoting normal wound healing while reducing pathological fibrosis (scar formation). The tripeptide also resets DNA repair gene expression and activates antioxidant response elements. GHK's gene expression signature broadly reverses the pattern seen in COPD, metastatic cancer, and tissue aging, suggesting it functions as a systemic tissue-reset signal.
Research Benefits
GHK at a Glance
GHK has a strong natural affinity for copper(II) ions, and much of its biological activity is mediated through copper delivery to cells and copper-dependent enzyme activation.
Massive Gene Expression Modulation
Strong EvidenceConnectivity Map analysis shows GHK modulates 4,000+ human genes, broadly resetting expression toward healthier, younger patterns. Upregulates repair genes, downregulates inflammatory/destructive genes.
Collagen and ECM Stimulation
Strong EvidenceStimulates synthesis of collagen I, III, IV, decorin, fibronectin, and glycosaminoglycans. Promotes organized ECM deposition for tissue structure and function.
Wound Healing Acceleration
Strong EvidenceWell-documented wound healing acceleration through fibroblast recruitment, angiogenesis stimulation (VEGF), and ECM remodeling. Reduces scar formation while promoting regenerative healing.
Antioxidant Defense Enhancement
Moderate EvidenceIncreases SOD, glutathione, and other antioxidant enzyme activity. Activates Nrf2-mediated antioxidant response elements for thorough oxidative stress protection.
Anti-Inflammatory Activity
Moderate EvidenceSuppresses inflammatory cytokine expression (IL-6, TNF-α, IL-1β) and reduces NF-κB signaling. Shifts immune balance from destructive to reparative.
Anti-Fibrotic (Scar Reduction)
Moderate EvidenceModulates TGF-β to promote normal healing while preventing excessive fibrosis. Reduces scar tissue formation by remodeling collagen deposition patterns.
Research Dosing Protocols
Research Purposes Only: All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.
| Research Protocol | Dose Range | Route |
|---|---|---|
| Subcutaneous research protocol | 200–500 mcg | Subcutaneous injection |
| Topical (requires modification or penetration enhancer) | 0–0 1-3% in formulation | Topical application |
Frequency
Once daily (injectable); twice daily (topical)
Timing
No specific timing requirements
Cycle Length
4-12 weeks for injectable research; ongoing for topical
Research Notes
- 1Native GHK has limited topical penetration — Pal-GHK or GHK-Cu are preferred for topical use.
- 2In plasma, GHK rapidly binds available copper(II) to form GHK-Cu.
- 3Plasma levels decline ~60% from age 20 to 60; supplementation aims to restore youthful levels.
- 4GHK is the parent molecule; GHK-Cu and Pal-GHK are optimized derivatives.
- 5Injectable GHK is used in research settings; topical derivatives are more commercially available.
Reconstitution Guide
Standard Reconstitution
Vial Size
5 mg
Bacteriostatic Water
2 mL
Concentration
25 mcg
per 0.1 mL (10 units)
Step-by-Step Guide
Gather Materials
GHK vial, bacteriostatic water, alcohol swabs, insulin syringes.
Equilibrate Temperature
Remove the vial from storage and allow it to reach room temperature (5-10 minutes).
Sanitize
Swab the rubber stopper of both the peptide vial and bacteriostatic water vial with alcohol.
Draw Water
Draw 2 mL of bacteriostatic water into a syringe.
Add Water to Vial
Insert the needle into the peptide vial and direct the water stream against the glass wall — not directly onto the powder.
Mix Gently
Swirl the vial gently until the powder is fully dissolved. Never shake. The solution should be clear and colorless.
Store Properly
Refrigerate at Refrigerated (2-8°C) after reconstitution. Up to 30 days refrigerated.
Storage Temperature
Refrigerated (2-8°C) after reconstitution
Shelf Life
Up to 30 days refrigerated
Important Notes
- •Reconstitute with bacteriostatic water.
- •GHK will naturally chelate copper from the solution or body fluids.
- •Small, stable tripeptide.
- •Store lyophilized powder refrigerated or frozen.
GHK Dosing Calculator
Calculate daily intake, cycle totals, and vials needed with pre-filled protocols →
GHK Reconstitution Calculator
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Safety & Side Effects
Reported Side Effects
- !Injection site reactions (mild)
- !Generally very well tolerated, endogenous molecule
- !No significant adverse effects reported in research literature
- !Topical: mild irritation in sensitive skin (rare)
Potential Interactions
- ⚡GHK naturally chelates copper(II) — forms GHK-Cu spontaneously.
- ⚡Topical GHK-Cu is incompatible with vitamin C (copper oxidizes ascorbic acid).
- ⚡Native GHK (without copper) is compatible with most actives.
- ⚡May enhance wound healing effects of other growth factors.
- ⚡Compatible with BPC-157 and TB-500 in tissue repair protocols.
Important: Side effects and interactions listed here are compiled from published research and community reports. This is not a complete list. No formal drug interaction studies have been conducted for most research peptides. Always consult a qualified healthcare provider.
Research Studies
The following studies are referenced in this profile. PubMed IDs are provided where available for independent verification.
GHK peptide modulates expression of 4,048 human genes
Connectivity Map analysis revealing GHK affects 31.2% of human gene expression, broadly reversing age-related gene expression patterns including upregulation of DNA repair, antioxidant, and ECM genes.
Tripeptide GHK induces tissue remodeling and collagen synthesis
thorough review of GHK's tissue remodeling capacity including collagen synthesis stimulation, MMP modulation, and organized ECM deposition in wound healing and anti-aging contexts.
GHK-copper peptide: wound healing and anti-aging effects
Foundational review of GHK's discovery, copper-binding properties, and biological effects spanning wound healing, tissue regeneration, and anti-inflammatory activity.
Gene expression signatures of GHK reverse COPD and cancer patterns
Demonstrated GHK's gene expression signature opposes the destructive expression patterns found in COPD lung tissue and metastatic cancer, suggesting therapeutic potential beyond cosmetic applications.
GHK peptide stimulates nerve growth factor and stem cell markers
Showed GHK upregulates NGF, VEGF, FGF-2, and various stem cell-related genes, supporting its role as a broad tissue regeneration signal.
Note: This is not an exhaustive list of all published research. Studies are selected for relevance and quality. Click PubMed IDs to verify sources independently. Inclusion does not imply endorsement of the peptide for any clinical use.
Frequently Asked Questions
GHK (Glycyl-Histidyl-Lysine) is a naturally occurring tripeptide found in blood plasma that declines with age. It modulates 4,000+ genes and is the parent molecule of GHK-Cu (copper peptide) and Pal-GHK (cosmeceutical peptide).
GHK is the base tripeptide. GHK-Cu has copper bound to it (used for wound healing and injectable/topical applications). Pal-GHK has a palmitic acid chain (optimized for cosmetic skin penetration). All share the core GHK biological activity but are optimized for different delivery methods.
Plasma GHK drops from ~200 ng/mL at age 20 to ~80 ng/mL by age 60. The mechanism of decline is not fully understood but correlates with reduced tissue repair capacity, slower wound healing, and age-related gene expression changes that GHK supplementation can partially reverse.
GHK appears to act as a master tissue-repair signal rather than a single-pathway drug. Through copper delivery, transcription factor modulation, and gene expression resetting, it broadly shifts cellular programs from aged/inflammatory toward youthful/reparative states. The Connectivity Map analysis validated this at genome-wide scale.
For topical skincare: Pal-GHK (best skin penetration) or GHK-Cu (copper benefits + skin). For injectable tissue repair: GHK-Cu (most studied injectable form). For research: native GHK to study the base molecule. Each form delivers GHK's core biology through optimized delivery.
Research & Educational Use Only
All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.
The information presented here is compiled from published research studies and is intended for informational purposes only. Individual results may vary. Always consult with a licensed healthcare provider.