Efficacy and safety of Anas barbariae 200K in influenza-like illness: a randomized double-blind, placebo-controlled, multicenter study

Objective Influenza-like illness (ILI) is characterized by the sudden onset of systemic and respiratory symptoms such as fever, fatigue and myalgia, requiring prompt management. Anas barbariae 200K, a homeopathic medicinal product, is traditionally used to relieve flu-like symptoms. This study aimed to evaluate its efficacy in alleviating ILI symptoms within 72 hours. Secondary outcomes assessed symptoms relief, adverse effects, functional outcomes, compliance, and participant and investigator satisfaction. Methods This prospective, randomized, double-blind, placebo-controlled multicenter superiority trial with two parallel groups was conducted in primary care in India in 2021. Children (6-12 years) and adults (18-65 years) with ILI symptoms for less than 24 hours were randomized to receive either Anas barbariae 200K (Oscillococcinum(R)) or placebo. Treatment was given three times daily for three days. The primary endpoint was the proportion of participants with alleviation of ILI symptoms within 72 hours following the initiation of treatment. Results A total of 707 participants received Anas barbariae 200K (n = 352) or placebo (n = 355). Within 72 hours, the Anas barbariae 200K group showed significantly greater symptom relief than the placebo group (74% vs. 44.5%; p < 0.0001). Secondary endpoints also favored Anas barbariae 200K group, including faster symptom alleviation (46.7 vs. 67.3 hours; p < 0.0001) and shorter median time, estimated by KM analysis, to return to daily activities (4.0 vs. 6.0 days; p < 0.0001). No serious adverse events were reported. Conclusion Anas barbariae 200K significantly alleviated ILI symptoms within 72 hours, with improvements that were both statistically and clinically significant. Significant benefits were also observed across secondary outcomes, with no safety signal identified. This study showed that Anas barbariae 200K could be an effective and well-tolerated treatment for ILI symptoms. Trial registration Clinical Trials Registry of India, CTRI: 2021/02/031250, registered on February 12, 2021. Keywords Influenza-like illness, Oscillococcinum(R), Respiratory tract infections, Randomized controlled trial, Homeopathy, Respiratory and systemic symptoms, Treatment outcome.