Used product in my family for years. Used 2 ways. For preventive , I would give a spoonful at bedtime to my kids during the entire cold season. They either never or rarely got a cold. At the onset of a bronchial type cold works great 2-3 times a day. Did not seem to work as well for sinus type colds. Key to use to avoid a cold. My now adult children request me to find and ship for them when they can't find in their local store.