Thymulin vs FOXO4-DRI
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.
- FOXO4-DRI is a D-retro-inverso peptide derived from the FOXO4 protein that selectively induces apoptosis in senescent cells. By disrupting the FOXO4-p53 interaction that keeps senescent cells alive, it triggers programmed cell death specifically in these aging, pro-inflammatory cells while sparing healthy tissue.
- Half-Life
- ~30 minutes active half-life
- Estimated 2-4 hours (D-amino acid confers resistance to proteolysis)
- Admin Route
- SubQ
- Subcutaneous, Intraperitoneal (research)
- Research
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- Typical Dose
- 20-30 mcg
- 5 mg/kg in rodent studies; human equivalent approximately 0.5-1 mg/kg
- Frequency
- 10 days per month (Khavinson protocol)
- 3 consecutive days per cycle
- 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
- Selectively clears senescent cells (senolytics)
- Reduces senescence-associated secretory phenotype (SASP) and chronic inflammation
- Demonstrated restoration of physical fitness in aged mice
- May improve healthspan and reduce age-related tissue dysfunction
- Potential for treatment of age-related pathologies driven by cellular senescence
- Does not affect healthy non-senescent cells at therapeutic doses
- Side Effects
- Injection site reactions
- Mild fatigue initially as immune system activates
- Limited human data; largely preclinical evidence
- Possible temporary inflammatory response as senescent cells are cleared (senolytic effect)
- Weight loss observed at high doses in rodent studies
- Unknown long-term safety profile in humans
- Stacks With
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