Best practice: Use Red light into each nasal passage for 1 – 3 minutes per nostril every 2 – 3 times per day along with other Light Therapy intervention. To deliver an adequate dose of light to denature COVID-19 virus that is residing in the nasal passages within a short period , we recommend a high-intensity torch with fiber-optic probe for best results. For those on a limited budget, a micro-light is also effective.