If you occasionally take 999 cold and flu granules is no side effects, because it is non-prescription drugs, safety is relatively high, but in the long-term large number of taking 999 cold and flu granules there may be some adverse reactions and side effects, roughly the following aspects: a. appear more sleepy, drowsy, dry mouth, thirst, weakness and other symptoms, some patients may also appear allergic reactions, such as skin rash, hives, drug rash or blood changes, including granulocytopenia. Some patients may have allergic reactions, such as skin rash, urticaria, drug rash or changes in blood picture, including granulocytopenia. Abnormal liver and kidney function, patients may have elevated liver enzymes and renal insufficiency. Third, it may lead to bleeding or anemia, renal colic, sweating, anxiety, insomnia, headache and other symptoms, so take 999 cold and flu granules should be applied under the guidance of a doctor, do not take a large number of long-term.