How long after taking ibuprofen will the fever subside?

　　Ibuprofen is a non-steroidal anti-inflammatory drug, commonly available in tablets, capsules, and other forms. Generally, the fever-reducing effects begin 30 minutes to 1 hour after taking ibuprofen. For most people, body temperature significantly decreases about 2 hours after taking the medication. The fever-reducing effect usually lasts 4-6 hours, although the exact duration may vary depending on individual physiology, severity of fever, and other factors. Detailed explanation is as follows:

　　Ibuprofen regulates body temperature by inhibiting prostaglandin synthesis. After administration, the drug needs to be absorbed through the gastrointestinal tract into the bloodstream to exert its effects. For individuals with a body temperature between 38.5℃ and 39℃ and good gastrointestinal function, the sensation of fever usually starts to alleviate after 30 minutes. If the body temperature exceeds 39℃ or an individual has a slower metabolism, the onset of action may take longer, typically starting to significantly reduce fever after 1-1.5 hours, though generally not exceeding 2 hours. Several factors influence the time required for fever reduction, including body temperature level, metabolic speed, and also the method of administration. Additionally, ibuprofen can only relieve the symptom of fever. If the underlying cause of the fever is not controlled, body temperature may rise again after the medication's effects wear off.

　　During the period of taking ibuprofen to reduce fever, it is important to drink plenty of warm water to promote sweating and heat dissipation, thus helping to lower body temperature. At the same time, avoid wearing excessive clothing and ensure good indoor ventilation.