Acetaminophen

Pronunciation: (uh-see-tuh-MIN-oh-fen).

Generic name
acetaminophen
Brand names
Dymadon, Pacimol, FeverAll, Tylenol, Atasol, Mapap
Drug class
Analgesic, Antipyretic

Availability and supply rules vary by country

Trade names by country: United States · Canada

Australia: · Full directory

What acetaminophen is and how it works

Uses, formulations, monitoring, and supply rules can differ by patient, product, and country. Follow the exact local product information and professional advice.

Mechanism of action: how acetaminophen works

Acetaminophen acts primarily in the central nervous system, increasing the pain threshold by inhibiting the cyclooxygenase (COX) pathway, particularly COX-2, and blocking the synthesis of prostaglandins involved in pain and fever. It has minimal anti-inflammatory activity due to weak peripheral inhibition of prostaglandin synthesis. (1)

What acetaminophen is used for

Pain relief

Pain relief

Fever reduction

Fever reduction

Headache relief

Headache relief

Muscle ache relief

Muscle ache relief

Before taking acetaminophen

Do not take / not appropriate for

  • Known hypersensitivity to acetaminophen, severe hepatic impairment or active liver disease. (Contraindication)

Tell your clinician about

How to take acetaminophen

  • General Instructions: Take exactly as directed on the label or by your healthcare provider. Do not exceed the recommended dose.. Adult Dosing: Typical adult dose: 325–1000 mg every 4–6 hours as needed. Maximum: 4000 mg in 24 hours.. Pediatric Dosing: Dose is based on child’s weight and age. Always use the dosing device provided and consult a healthcare provider for correct dosing.. Administration: Can be taken with or without food. Swallow tablets whole with water. Liquid forms should be measured with a dosing syringe or cup.. When To Seek Review: Contact your doctor promptly if pain or fever lasts more than a few days, or if new symptoms develop.. Storage: Store at room temperature, away from moisture and heat. Keep out of reach of children.
  • This page does not provide a dose calculator. Dosing must follow the prescriber, pharmacist, or product label.

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician.

Missed dose

Tylenol is usually taken only as needed for pain or fever, so there is normally no missed dose to make up. If you are on a scheduled regimen and miss a dose, contact your prescriber or pharmacist for guidance rather than deciding on your own — do not take an extra dose to catch up.

Overdose

Acetaminophen overdose can cause severe liver damage and can be fatal. If you suspect an overdose, seek emergency medical help or contact a poison control center immediately. Early symptoms may include nausea, vomiting, sweating, and general malaise.

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms to a healthcare professional.

Nausea

Incidence: Reported in the clinician-authored database; frequency not established

Vomiting

Incidence: Reported in the clinician-authored database; frequency not established

Abdominal pain

Incidence: Reported in the clinician-authored database; frequency not established

Rash

Incidence: Reported in the clinician-authored database; frequency not established

Hives

Incidence: Reported in the clinician-authored database; frequency not established

Itching

Incidence: Reported in the clinician-authored database; frequency not established

Yellowing of skin or eyes

Incidence: Reported in the clinician-authored database; frequency not established

Dark urine

Incidence: Reported in the clinician-authored database; frequency not established

Serious warnings

Do not exceed 4000 mg in 24 hours — serious

Symptoms: Do not exceed 4000 mg in 24 hours. Check all medications for acetaminophen content. Consult a doctor before use if you have liver disease. Seek medical advice if pregnant or breastfeeding. Keep out of reach of children.

Action: Follow the urgency stated and seek prompt or emergency care when indicated.

Contraindications recorded in the clinician database — serious

Symptoms: Contraindications recorded in the clinician database: Contraindications: Known hypersensitivity to acetaminophen, severe hepatic impairment or active liver disease. Precautions: Use with caution in patients with chronic alcoholism, mild to moderate hepatic impairment, or malnutrition. Monitor for signs of hepatotoxicity, especially with prolonged use or high doses.

Action: Follow the urgency stated and seek prompt or emergency care when indicated.

Interactions

Medicine or testEffectAction
Recorded interactionsAcetaminophen may interact with certain medications, including warfarin (increased bleeding risk), isoniazid, some anti-seizure drugs, and alcohol. Always inform your healthcare provider about all medicines you are taking. (1)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

The US OTC Drug Facts label instructs: if pregnant, ask a health professional before use. Acetaminophen is widely used for pain and fever in pregnancy, but the decision and dose should come from your healthcare provider.

Breastfeeding

The US OTC Drug Facts label instructs: if breast-feeding, ask a health professional before use. Discuss with your healthcare provider or pharmacist before using while breastfeeding.

Children

Frequency: Every 4-6 hours as needed. Weight Based: 10-15 mg/kg/dose every 4-6 hours as needed. Max Daily Dose: 75 mg/kg/day (up to 3000 mg). Max Single Dose: 15 mg/kg (up to 500 mg). Age Restrictions: Not recommended for pediatric use under 2 months of age

Renal_impairment

If you have liver disease or drink 3 or more alcoholic drinks a day, ask a healthcare provider before using acetaminophen — the label carries a specific severe-liver-damage warning. If you have significant kidney disease, ask your healthcare provider or pharmacist before regular use; they may advise a lower total daily dose or longer dosing intervals.

Hepatic_impairment

If you have liver disease or drink 3 or more alcoholic drinks a day, ask a healthcare provider before using acetaminophen — the label carries a specific severe-liver-damage warning. If you have significant kidney disease, ask your healthcare provider or pharmacist before regular use; they may advise a lower total daily dose or longer dosing intervals.

Monitoring

Storage

Store at room temperature, 20–25°C (68–77°F), away from excess heat and moisture. Keep tightly closed and out of reach of children.

Professional information

Clinician-facing context only. This section does not replace current product labeling.

General

Indication: Pain relief

Dose summary: 325-650 mg every 4-6 hours as needed

Renal context: The OTC label does not mandate a specific renal dose adjustment. Clinical practice note: in significant renal impairment, clinicians commonly extend the dosing interval (e.g. every 6-8 hours) and keep total daily dose conservative; hepatic impairment and chronic alcohol use are the label-flagged risk groups (severe-liver-damage warning at >4,000 mg/day). (1)

Mechanism of action

Frequently asked questions

What is Tylenol (acetaminophen) used for?

Tylenol is used to relieve mild to moderate pain (such as headaches, muscle aches, arthritis, backache, toothaches, and menstrual cramps) and to reduce fever.

How quickly does Tylenol work?

Tylenol usually starts to work within 30 to 60 minutes after taking a dose.

Can I take Tylenol with other pain relievers?

You can take Tylenol with NSAIDs (like ibuprofen) if needed, but do not take it with other acetaminophen-containing products.

Is Tylenol safe during pregnancy?

Acetaminophen is generally considered safe during pregnancy when used as directed, but always consult your healthcare provider first.

What should I do if I accidentally take too much Tylenol?

Seek emergency medical attention immediately, even if you feel well. Overdose can cause serious liver damage.

Can children take Tylenol?

Yes, Tylenol is safe for children when dosed appropriately by weight and age. Use only pediatric formulations and dosing devices.

Does Tylenol cause stomach upset or bleeding like NSAIDs?

Tylenol is less likely to cause stomach upset or bleeding compared to NSAIDs, but it can cause liver damage if overused.

What happens if I take too much Tylenol (acetaminophen)?

Taking too much Tylenol (acetaminophen) can lead to a serious overdose, potentially causing liver damage, nausea, vomiting, abdominal pain, and jaundice. In severe cases, it can be fatal. If you suspect an overdose, seek immediate emergency medical attention or contact poison control. Do not wait for symptoms to appear.

Can I drink alcohol while taking Tylenol (acetaminophen)?

It is generally advised to avoid or limit alcohol consumption while taking Tylenol (acetaminophen). Both acetaminophen and alcohol are metabolized by the liver, and combining them can increase the risk of liver damage. This risk is particularly elevated for individuals who consume alcohol regularly or in large quantities. Consult your healthcare provider for personalized advice.

Is Tylenol (acetaminophen) safe during pregnancy?

Tylenol (acetaminophen) is generally considered to be in Pregnancy Category B, meaning animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women. However, it is crucial to consult your doctor before taking any medication during pregnancy to ensure it is safe for your specific situation and to discuss appropriate dosing.

What is the mechanism of action of acetaminophen?

Acetaminophen acts primarily in the central nervous system, increasing the pain threshold by inhibiting the cyclooxygenase (COX) pathway, particularly COX-2, and blocking the synthesis of prostaglandins involved in pain and fever. It has minimal anti-inflammatory activity due to weak peripheral inhibition of prostaglandin synthesis. (1)

What is the generic name of Acetaminophen?

The generic name is acetaminophen. It is sold under brand names including Dymadon, Pacimol, FeverAll, Tylenol, Atasol, Mapap.

What class of drug is acetaminophen?

Acetaminophen is classed as: Analgesic, Antipyretic.

References

  1. TYLENOL (acetaminophen) — OTC Drug Facts label (DailyMed) · · accessed 2026-08-08 · source 1
  2. Acetaminophen — MedlinePlus Drug InformationMedlinePlus, U.S. National Library of Medicine · United States · accessed 2026-08-08 · source 2
  3. ACETAMINOPHEN INJECTION, SOLUTION [CIVICA, INC.] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 3
  4. Acetaminophen — patient drug information (MedlinePlus)U.S. National Library of Medicine (MedlinePlus) · US · accessed 2026-08-14 · source 4
  5. Pain Reliever Extra Strength — FDA approval record (Drugs@FDA M013)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 5
  6. acetaminophen — RxNorm normalized drug concept (RXCUI 161)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 6

Brand names by country

Single-ingredient acetaminophen names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • Arthritis Pain650 mg · aaa pharmaceutical, inc.
  • Tylenol 8HR500 mg, 960 mg/30mL, 650 mg, 500 mg/.95g, 325 mg, 160 mg/5mL · a-s medication solutions
  • 8HR Arthritis Pain650 mg · harris teeter
  • Pharbetol325 mg, 500 mg · atlantic biologicals corp.
  • 8 Hour Arthritis Pain650 mg · amerisource bergen
  • M-PAP160 mg/5mL · bryant ranch prepack
  • childrens mapap160 mg, 80 mg · proficient rx lp
  • 8 hr arthritis pain650 mg · dolgencorp, inc.
  • 8HR Muscle Aches and Pain650 mg · leader/ cardinal health 110, inc.
  • good sense pain relief arthritis pain650 mg · l. perrigo company

Canada

  • TYLENOL
  • ACETAMINOPHENE
  • ACET
  • PEDIAPHEN CHILDREN'S ACETAMINOPHEN
  • ABENOL
  • ATASOL
  • ACÉTAMINOPHÈNE COMPRIMÉ
  • CHILDREN'S ACETAMINOPHEN
  • PEDIATRIX
  • CHILDREN'S CHEWABLE ACETAMINOPHEN
View brands in additional countries.

General information only — not a diagnosis, prescription, or substitute for professional medical advice.

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