GHK

What is GHK?

You might know GHK-Cu (with copper) as a skincare ingredient, but GHK on its own is a fascinating tripeptide that your body naturally produces. It was first isolated from human plasma in 1973, and its levels decline significantly with age — from about 200 ng/mL at age 20 to 80 ng/mL by age 60. This decline tracks with the visible signs of ageing.

What makes GHK remarkable is not just what it does, but how broadly it does it. Gene expression studies show that GHK can reset the expression of over 4,000 genes toward a younger, healthier pattern. It upregulates genes involved in tissue repair, antioxidant defence, and stem cell activity while downregulating genes associated with inflammation and tissue destruction. It is essentially a gene expression reset signal.

Without the copper attachment, GHK still retains significant bioactivity, particularly for systemic tissue repair signalling. The copper-free form is preferred by some practitioners for injectable use where copper accumulation might be a concern with chronic dosing.

How Does It Work?

GHK modulates gene expression through multiple mechanisms:

1. Activates tissue remodelling — stimulates collagen synthesis, decorin, glycosaminoglycans, and other extracellular matrix components. 2. Antioxidant gene upregulation — increases superoxide dismutase, glutathione, and other antioxidant systems. 3. Anti-inflammatory — suppresses NF-kB, reduces TGF-beta (at fibrotic levels), modulates IL-6 and TNF-alpha. 4. Stem cell attraction — signals mesenchymal stem cells to injury sites. 5. Metalloproteinase regulation — balances tissue breakdown and rebuilding.

Without copper, GHK still performs receptor-mediated signalling but loses some of the direct enzymatic cofactor activity that copper provides.

What Does The Research Say?

Gene expression: Large-scale genomic studies (Broad Institute Connectivity Map) confirm GHK resets thousands of genes toward youthful expression patterns. This is some of the most compelling data for any anti-ageing peptide.

Wound healing: Clinical and preclinical data showing accelerated wound healing, improved skin quality, and tissue repair.

Systemic effects: Animal studies show anti-fibrotic, anti-inflammatory, and tissue-protective effects across multiple organs.

Most clinical data uses GHK-Cu topically. Injectable GHK (with or without copper) has less published human data but strong mechanistic support.

Reported Dosages

Subcutaneous: 1-2mg daily or every other day (commonly used protocol).

Some practitioners cycle 5 days on, 2 days off.

Can be combined with GHK-Cu topically for skin-specific benefits.

Available from peptide suppliers as lyophilised powder for reconstitution.

DISCLAIMER: Injectable GHK is a research peptide without regulatory approval for human use. Dosing protocols are based on practitioner experience, not clinical trials.

Side Effects & Risks

Very well-tolerated in available reports. Mild injection site reactions possible. Without copper, there is no concern about copper accumulation. Theoretical: as a growth-signalling peptide, there is always the question of whether it could promote growth of existing cancers — no evidence this occurs, but prudent to avoid during active malignancy.

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