Thymulin vs GHK
Side-by-side comparison of key properties, dosing, and research.
- Summary
- Thymulin is a nonapeptide hormone produced exclusively by the thymic epithelium. It requires zinc for biological activity and plays a critical role in T-lymphocyte maturation, differentiation, and immune regulation. Thymulin levels decline dramatically with age, contributing to immunosenescence.
- 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.
- Half-Life
- ~30 minutes active half-life
- Extremely short as free peptide; tissue binding extends local effects
- Admin Route
- SubQ
- SubQ, Topical, Oral
- Research
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- Typical Dose
- 20-30 mcg
- 100–500 mcg
- Frequency
- 10 days per month (Khavinson protocol)
- Daily or 5x per week
- Key Benefits
- Enhances T-cell maturation and differentiation
- Boosts NK cell cytotoxic activity
- Reduces inflammatory cytokine production (TNF-α, IL-1)
- Anti-nociceptive (pain-reducing) properties
- Restores age-related immune decline
- Anti-inflammatory via serotonin pathway modulation
- 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
- Side Effects
- Injection site reactions
- Mild fatigue initially as immune system activates
- Excellent safety profile (naturally occurring peptide)
- Rare: mild injection site reaction (SC)
- No significant adverse effects identified in research
- Stacks With
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