Been using Yinqiao for over 40 years for cold, flu, and allergy symptoms. If taken like it should be - start taking the moment you feel something, three times/day, four tablets each time, and don't stop until it's gone - it works except in the MOST intense situations (like running in a field of wild flowers in early May!). It not only minimizes the symptoms, but can VERY quickly curtail a cold coming on, and for me and my family, there are NO side effects. A staple that flat works. And this brand has been the best for us, and is very consistent. Solstice Medicine is one of the most reliable suppliers and easy to work with.