The effect time of antipyretic drugs is determined by the half-life and absorption of the drug, and most patients can have an effect after 30-60 minutes, but the effect time varies slightly depending on individual differences. Most fevers are caused by infections, and the pathogens include bacteria, viruses, mycoplasma, etc. It is recommended that patients have routine blood tests to identify the pathogens before treatment. When the patient’s body temperature exceeds 38.5℃, fever-reducing drugs can be used as appropriate. Different fever-reducing drugs have different onset times depending on their dosage, manufacturer, and type of drug, and usually take effect in about 30-60 minutes. In addition, after taking antipyretic drugs for better effect, it is necessary to drink more water appropriately. It is important to note that the reduction of fever does not mean that the disease has been cured, and if the effect of the drug wears off, a fever may occur again. Patients are advised to go to the hospital to clarify the cause of the fever and not to take antipyretic drugs on their own to cover up the condition and delay the treatment of the disease.