I was traveling on business in China. Between the airplane air quality and the cities in China, something gave me a sore throat and cough and general under the weather feeling. I happened to bring a bottle of Colflex with me on the trip and started to use it as soon as I felt the tickle in the back of my throat. Within a day, my throat felt better and I continued on using it for the next two weeks for prevention and did not have any further issues. Thanks for the effective natural product.