COMPOUND

Compounds / Healing

GHK

GHK (Glycyl-L-Histidyl-L-Lysine; non-copper-bound tripeptide)

Healing Topical · SubQ Not FDA approved

Endogenous tripeptide present in human plasma, saliva, and urine. Plasma concentration ~200 ng/mL at age 20, declining to ~80 ng/mL by age 60. The 'free' GHK (without copper) has distinct biological activity from the copper-bound complex GHK-Cu, particularly in gene-expression signatures revealed by the Broad Institute Connectivity Map. Available OTC as cosmetic ingredient (Tripeptide-1); SubQ form is research peptide.

At a glance

Half-life
~30 min Plasma half-life short (minutes); local tissue effect persists hours-days via gene expression changes.
Routes
Topical · SubQ
Vial sizes
50 mg · 100 mg · 200 mg
Evidence base
2 studies 2 review

Mechanism

GHK (free) mechanisms emerging since Connectivity Map analyses (post-2010): modulates expression of >4,000 genes (copper-independent activity established); stimulates collagen, elastin, glycosaminoglycan synthesis (skin matrix); anti-inflammatory (reduces TNF-α, oxidative stress markers); pro-angiogenic (stimulates VEGF and capillary outgrowth); stem cell activation in keratinocytes; wound healing acceleration: copper-free pathways documented in skin regeneration. GHK-Cu has additional copper-dependent effects (free radical scavenging, copper transport). Where GHK-only is sufficient, free GHK avoids copper accumulation issues.

Dosing

No standardized human dosing has been established. Every catalogued study for GHK is preclinical or a literature review. Amounts used in animal models do not translate directly to humans.

Published evidence

  1. Review 2018

    Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data

    Pickart L, Margolina A Int J Mol Sci

    Comprehensive review of GHK and GHK-Cu mechanisms, including Connectivity Map analyses showing free GHK modulates >4000 genes: copper-independent activity established.

  2. Review 2015

    GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration

    Pickart L, Vasquez-Soltero JM, Margolina A Biomed Res Int

    Comprehensive mechanism review of GHK in skin regeneration; documented copper-free pathways.

Reported side effects

Topical irritation
Rare Mild · Generally very well-tolerated topically.
Injection site reaction
Occasional Mild · SubQ; mild local.

Interactions

  • GHK-Cu Redundant

    GHK is the base tripeptide; GHK-Cu is the copper-bound complex. Connectivity Map data shows distinct gene expression signatures so they're not perfectly redundant, but mechanism overlap is substantial.

Reconstitution and storage

Topical: 50-200 mg powder + 100 mL serum carrier. SubQ: lyophilized + BAC water at 2 mg/mL.

Lyophilized: refrigerated for long-term. Reconstituted: refrigerated.

Open the reconstitution calculator for GHK