Nilavembu (Andrographis paniculata) is a versatile medicinal herb widely used in traditional Ayurvedic and Siddha medicine for its numerous health benefits. It possesses potent antiviral, antibacterial, anti-inflammatory, and hepatoprotective properties, making it effective in treating conditions like viral fevers (dengue, chikungunya), liver disorders, digestive issues, and respiratory ailments. Nilavembu is also known to boost immunity, manage diabetes, and improve skin health. Common preparations include decoctions, topical applications, and fresh juice, with modern research supporting its traditional uses.