Effects of Viusid in Long COVID: A Randomized Double-Blind Placebo-Controlled Trial.

INTRODUCTION: Long COVID syndrome (LCS) is characterized by persistent neurological, respiratory, and systemic symptoms following SARS-CoV-2 infection, with limited effective treatments available. Viusid is an oral antioxidant and immunomodulatory formulation that may improve chronic inflammatory symptoms. This study evaluated the efficacy of Viusid in patients with LCS. METHODS: This randomized double-blind placebo-controlled clinical trial evaluated the efficacy and safety of Viusid in adults with long COVID syndrome. The primary endpoint was the change in brain fog severity at Day 210. Secondary endpoints included changes in neurological, respiratory, musculoskeletal, digestive, and general symptoms measured using a 23-symptom clinical questionnaire. RESULTS: All participants completed the study. Viusid significantly improved the primary endpoint, brain fog, compared with placebo (MD -1.23; 95% CI -2.41 to -0.005; p < 0.001). Significant improvements favoring Viusid were also observed in anxious-depressive mood (p < 0.001), sleep dis-orders (p = 0.003), fatigue (p = 0.023), dyspnea (p = 0.018), chest pain (p = 0.002), cough (p = 0.004), abdominal pain (p = 0.009), and myalgia (p = 0.025). These effects remained consistent after adjusted analyses. DISCUSSION: The intervention showed potential improvement in long COVID symptoms; however, the small sample size and observational design limit conclusions, warranting further randomized con-trolled studies. CONCLUSIONS: Viusid significantly improved multiple long COVID symptoms, particularly neurological and respiratory manifestations. These findings support its potential as a therapeutic option for long COVID and justify further confirmatory studies.