Paracetamol, or acetaminophen, is a non-opioid analgesic and antipyretic agent used to treat fever and mild to moderate pain. It is a widely available over-the-counter drug sold generically or under various various brand names, including Tylenol and Panadol.

Paracetamol relieves pain in both acute mild migraine and episodic tension headache. At a standard dose, paracetamol slightly reduces fever, though it is inferior to ibuprofen in that respect and the benefits of its use for fever are unclear, particularly in the context of fever of viral origins. The aspirin/paracetamol/caffeine combination also helps with both conditions when the pain is mild and is recommended as a first-line treatment for them. Paracetamol is effective for pain after wisdom tooth extraction, but it is less effective than ibuprofen. The combination of paracetamol and ibuprofen provides greater analgesic efficacy than either drug alone. The pain relief paracetamol provides in osteoarthritis is small and clinically insignificant. Evidence supporting its use in low back pain, cancer pain, and neuropathic pain is insufficient. Paracetamol is the first-line treatment for pain and fever in pregnancy; no causal association with neurodevelopmental disorders has been established, while untreated pain and fever can harm the mother and fetus.

In the short term, paracetamol is safe and effective when used as directed. Short term adverse effects are uncommon and similar to ibuprofen. Paracetamol is typically safer than nonsteroidal anti-inflammatory drugs (NSAIDs) for long-term use. Paracetamol is also often used in patients who cannot tolerate NSAIDs like ibuprofen. Chronic consumption of paracetamol may result in a drop in hemoglobin level, indicating possible gastrointestinal bleeding, and abnormal liver function tests. The recommended maximum daily dose for an adult is three to four grams. Higher doses may lead to toxicity, including liver failure. Paracetamol poisoning is the foremost cause of acute liver failure in the Western world, and accounts for most drug overdoses in the United States, the United Kingdom, Australia, and New Zealand.

Paracetamol was first made in 1878 by Harmon Northrop Morse or possibly in 1852 by Charles Frédéric Gerhardt. It is the most commonly used medication for pain and fever in both the United States and Europe. It is on the World Health Organization's List of Essential Medicines. Paracetamol is available as a generic medication, with brand names including Tylenol and Panadol among others. In 2023, it was the 112th most commonly prescribed medication in the United States, with more than 5 million prescriptions.

Paracetamol is used for reducing fever. However, there has been a lack of research on its antipyretic properties, particularly in adults, and thus its benefits are unclear. As a result, it has been described as over-prescribed for this application. In addition, low-quality clinical data indicates that when used for the common cold, paracetamol may relieve a stuffed or runny nose, but not other cold symptoms such as sore throat, malaise, sneezing, or cough.

For people in critical care, paracetamol decreases body temperature by only 0.2–0.3 °C more than control interventions and has no effect on their mortality. It did not change the outcome in febrile patients with stroke. The results are contradictory for paracetamol use in sepsis: higher mortality, lower mortality, and no change in mortality were all reported. Paracetamol offered no benefit in the treatment of dengue fever and was accompanied by a higher rate of liver enzyme elevation: a sign of potential liver damage. Overall, there is no support for a routine administration of antipyretic drugs, including paracetamol, to hospitalized patients with fever and infection.

The efficacy of paracetamol in children with fever is unclear. Paracetamol should not be used solely to reduce body temperature; however, it may be considered for children with fever who appear distressed. It does not prevent febrile seizures. It appears that 0.2 °C decrease of the body temperature in children after a standard dose of paracetamol is of questionable value, particularly in emergencies. Based on this, some physicians advocate using higher doses that may decrease the temperature by as much as 0.7 °C. Meta-analyses showed that paracetamol is less effective than ibuprofen in children (marginally less effective, according to another analysis), including children younger than 2 years old, with equivalent safety. Exacerbation of asthma occurs with similar frequency for both medications.

Paracetamol is used for the relief of mild to moderate pain such as headache, muscle aches, minor arthritis pain, and toothache, as well as pain caused by cold, flu, sprains, and dysmenorrhea. It is recommended, in particular, for acute mild to moderate pain, since the evidence for the treatment of chronic pain is insufficient.