Thymosin alpha-1 is a natural peptide made by the thymus that can boost the aging immune system. Studies show it helps the body make more T‑cells, improves vaccine responses in older people, and reduces chronic inflammation. A new hybrid drug that combines it with TNF‑alpha looks promising but is still experimental.

Aging is characterized by immune decline, mainly due to thymic involution-the age-related shrinkage of the thymus gland. This leads to reduced T-cell production, chronic inflammation, and increased susceptibility to age-related diseases. Thymosin alpha-1 (T&#x3b1;1), a peptide hormone produced by the thymus, exhibits potent immunomodulatory, anti-inflammatory, and antioxidant properties. It helps restore immune function by stimulating T-cell differentiation, enhancing thymic output, and modulating dendritic cell and macrophage activity. Preclinical and clinical studies show that T&#x3b1;1 can improve vaccine response in the elderly and mitigate immunosenescence. The hybrid drug <i>Refnot</i> (a fusion of tumor necrosis factor alpha (TNF&#x3b1;) and T&#x3b1;1) combines T&#x3b1;1's immunomodulation with TNF's antitumor activity but has reduced toxicity. It represents a promising therapeutic approach to counteract age-related immune dysfunction and inflammation, potentially by slowing the aging process. Further research is needed to validate its long-term efficacy and safety in geriatrics.