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

Get it free
ToolsCompareThymulin vs DS5

Thymulin vs DS5

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

Immune Support
Thymulin
Sleep Optimization
DS5
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.
DS5 is a synthetic variant of the delta sleep-inducing peptide (DSIP), a nonapeptide originally isolated from rabbit cerebrospinal fluid during slow-wave sleep. Like DSIP, DS5 is explored for sleep optimization, stress modulation, and circadian rhythm normalization, with proposed improvements in potency or stability over the parent molecule.
Half-Life
~30 minutes active half-life
Estimated 30-60 minutes (peptide degradation)
Admin Route
SubQ
Subcutaneous, Intranasal (research)
Research
Typical Dose
20-30 mcg
200-500 mcg per dose
Frequency
10 days per month (Khavinson protocol)
Once nightly
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
  • Promotes delta-wave (deep) sleep and improves sleep quality
  • May reduce sleep onset latency
  • HPA axis modulation for stress reduction
  • Non-addictive sleep support without tolerance development
  • Potential circadian rhythm normalization
  • Explored for insomnia, chronic stress, and PTSD-related sleep disturbance
Side Effects
  • Injection site reactions
  • Mild fatigue initially as immune system activates
  • Generally well-tolerated in research subjects
  • Possible morning grogginess at higher doses
  • Mild blood pressure fluctuations reported with DSIP
  • Limited human safety data for DS5 specifically
Stacks With