Not all cold capsules will cause patients to suffer from the side effects of drowsiness, cold capsules are generally compound preparations containing Chinese medicine, may also contain the ingredients of Western medicine, due to more ingredients, generally cause drowsiness, tiredness and other side effects are mainly paracetamol. Paracetamol is mainly for cold symptoms, such as nasal congestion, runny nose, sneezing, reduce the congestion of the upper respiratory tract mucosa, edema state, the most common side effects of paracetamol is drowsiness, sleepiness, fatigue, etc.. Therefore, as long as the cold capsules containing paracetamol ingredients, after taking them, there will be different degrees of drowsiness, but if the cold capsules do not contain paracetamol ingredients generally do not have the side effect of drowsiness.