GHK vs Testagen
Side-by-side comparison of key properties, dosing, and research.
- Summary
- GHK is the natural tripeptide (Gly-His-Lys) released from human albumin that activates tissue remodeling, collagen synthesis, and anti-aging gene expression. The copper-free form is the biological signaling molecule; it chelates copper in tissue to form GHK-Cu but also has independent biological activity.
- Testagen is a tetrapeptide bioregulator (Lys-Glu-Asp-Gly) developed by Professor Vladimir Khavinson, tissue-specific for the testes. It supports Leydig cell function, normalization of testosterone biosynthesis, and spermatogenic activity. Testagen is used in men's health protocols for age-related testosterone decline, male fertility support, and testicular anti-aging.
- Half-Life
- Extremely short as free peptide; tissue binding extends local effects
- Short (minutes); sustained gene-regulatory effects
- Admin Route
- SubQ, Topical, Oral
- SubQ, Oral
- Research
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- Typical Dose
- 100–500 mcg
- 10 mg per day
- Frequency
- Daily or 5x per week
- Daily for 10–30 days
- Key Benefits
- Stimulates collagen and extracellular matrix synthesis
- Activates tissue repair gene expression programs
- Anti-aging: reverses 57% of age-related gene changes
- Antioxidant and anti-inflammatory
- Wound healing and skin barrier repair
- Improves skin laxity, texture, and radiance
- Neuroprotective (stimulates NGF, BDNF)
- Anti-fibrotic in liver and lung models
- Supports endogenous testosterone synthesis via Leydig cell normalization
- Promotes spermatogenesis and sperm quality
- Anti-aging effects on testicular tissue
- May attenuate age-related testosterone decline
- Mechanistically distinct from TRT — does not suppress HPG axis
- Useful adjunct to Gonadorelin and Kisspeptin-10 in male hormonal protocols
- Supports male fertility without exogenous hormone replacement
- Side Effects
- Excellent safety profile (naturally occurring peptide)
- Rare: mild injection site reaction (SC)
- No significant adverse effects identified in research
- Generally well tolerated
- Mild injection site reactions
- No significant endocrine disruption reported at standard doses
- Stacks With
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