Thymosin alpha‑1 is an immune‑boosting peptide that, in several clinical studies, helped lower death rates and secondary infections in people with severe sepsis, especially when combined with anti‑inflammatory drugs. However, the benefits were seen mainly in patients whose immune systems were already weakened, and the research is still limited and variable.

Sepsis is a life-threatening organ dysfunction caused by host immune response to infection. In this regard, modifying host immune response may help to eliminate systemic infection and restore organ function. Thymosin alpha 1 (Tα1), acting as an immune modulator, exerts great biological influence in activating and restoring the dysregulated immune response for patients with sepsis. In this review, we summarize the clinical studies of Tα1 treatment alone and in combination with anti-inflammatory for patients with sepsis or septic shock. Clinical studies were collected from available English and Chinese databases. In previous studies, single or combined treatment with Tα1 reduced the mortality rate of sepsis, improved the expression of HLA-DR on monocyte, and diminished the incidence of secondary infection. Based on the existing studies, Tα1 seems to be a promising alternative adjuvant therapy for sepsis. However, sepsis is a remarkably heterogeneous clinical syndrome, so much so that it is impossible to generalize the clinical results to all septic patients. Also, the present studies on Tα1 treatment are not able to focus on the immunosuppressive individuals. We believe that selecting septic patients with immunosuppression will be more likely to reveal the efficacy of Tα1 in future trials.