New — Free Peptide Starter Guide (2026): 13 chapters, 34 cited studies

Get it free
ToolsCompareThymulin vs Pal-GHK

Thymulin vs Pal-GHK

Side-by-side comparison of key properties, dosing, and research.

Immune Support
Thymulin
Skin & CosmeticAnti-Aging & Longevity
Pal-GHK
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.
Pal-GHK is the palmitoylated form of the GHK tripeptide without a copper ion. By conjugating palmitic acid to glycine-histidine-lysine, skin penetration is substantially enhanced, enabling deeper dermal collagen stimulation. It is commonly paired with Pal-GHK-Cu or GHK-Cu in anti-aging formulations.
Half-Life
~30 minutes active half-life
Extended (lipid depot in stratum corneum)
Admin Route
SubQ
Topical
Research
Typical Dose
20-30 mcg
0.005–0.1% in formulation
Frequency
10 days per month (Khavinson protocol)
Once or twice daily
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 I and III synthesis in dermis
  • Reduces the appearance of fine lines and wrinkles
  • Improves skin elasticity and firmness
  • Inhibits collagenase (MMP-1) to preserve existing collagen
  • Enhances wound healing and skin repair
  • Well-tolerated in anti-aging serums and creams
Side Effects
  • Injection site reactions
  • Mild fatigue initially as immune system activates
  • Generally very well-tolerated
  • Rare skin irritation at very high concentrations
  • Possible formulation-dependent comedogenicity
Stacks With