Klotho vs Thymalin
A neutral, side-by-side comparison of two anti-aging & longevity peptides — their mechanisms, dosing ranges, administration routes, side effects, and research evidence. For research and educational purposes only.
Klotho
Anti-aging protein discovered in 1997 whose deficiency causes a syndrome resembling accelerated aging across multiple organ systems. Circulating soluble klotho declines ~40% from age 40–80. Research into klotho-derived peptides and recombinant protein explores neuroprotection, cardiac protection, renal anti-fibrosis, and metabolic anti-aging benefits. The KL-VS polymorphism provides a natural human model of elevated klotho activity.
Full profileThymalin
Thymus-derived peptide bioregulator developed in Russia containing a mixture of low-molecular-weight peptides extracted from calf thymus. Primarily studied for reversing immunological aging (immunosenescence) and extending healthy lifespan. Vladimir Khavinson's longitudinal research on elderly patients links thymalin administration to significant improvements in immune markers and all-cause mortality reduction.
Full profile| Klotho | Thymalin | |
|---|---|---|
| Category | Anti-Aging & Longevity | Anti-Aging & Longevity |
| Also known as | α-Klotho, soluble Klotho, KL-VS, klotho protein, KL1 domain | thymic peptide bioregulator, T-activin extract, thymus peptide, thymic bioregulator |
| Evidence | Research-stage | Research-stage |
| Dosing range | 1mcg/kg–10mcg/kg mcg/kg, every 3–7 days IV or SC (research) | 5mg–20mg mg, 5–10 day course, 1–2x per year |
| Administration | Intravenous (research), Subcutaneous injection | Intramuscular injection, Subcutaneous injection |
| Key side effects | Hypophosphatemia (klotho inhibits FGF23 signaling → phosphate wasting), Hypocalcemia (secondary to phosphate effects), Altered vitamin D metabolism, Potential for altered mineral homeostasis with chronic administration | Injection site reactions, Mild fever (rare), Temporary increase in immune activity (desired response), Rare hypersensitivity |
| Cited sources | 2 references | 2 references |
Key differences
- Administration: Klotho — Intravenous (research), Subcutaneous injection; Thymalin — Intramuscular injection, Subcutaneous injection.
- Dosing units differ: Klotho is dosed in mcg/kg, Thymalin in mg — they operate at different scales.
- Frequency: Klotho is typically every 3–7 days IV or SC (research); Thymalin is 5–10 day course, 1–2x per year.
How each works
Klotho
α-Klotho functions as both a transmembrane co-receptor for FGF23 (regulating phosphate and vitamin D) and as a shed soluble circulating factor with FGF23-independent longevity effects. Soluble klotho activates longevity-associated pathways: Nrf2/antioxidant defense, FOXO transcription factors, and Wnt/TGF-β inhibition for anti-fibrotic effects. The klotho-deficient mouse ages rapidly and dies young; klotho-overexpressing mice live 20–30% longer.
Thymalin
Thymalin contains multiple bioactive peptides that stimulate T-lymphocyte differentiation and restore thymic function that declines with age. In Khavinson's 6-year controlled trial of elderly patients (78–89 years), annual thymalin courses were associated with significantly lower mortality and improved immune parameters vs. controls. Proposed mechanisms include telomerase activation in immune cells and restoration of thymic epithelial cell function.
This comparison aggregates public research and structured profile data for informational purposes only. It is not medical advice and does not recommend either compound for human use. Consult a qualified healthcare provider before considering any peptide.