I had a virus for two days w/ low fever, sinus congestion, headache, achiness, and tiredness. I tried several remedies, like alkalizing with lemon juice and baking soda and also oil of oregano. I couldn't tell much difference. Then I tried 2 cups of Pau D'Arco tea, one in the afternoon & another that evening. I immediately felt somewhat better. The next morning, I felt a lot better - more energy, no headache, and just a runny nose. I drank 3 large cups throughout the day (using same teabag) and felt 100% better by evening. Even my nose stopped running. Amazing!