Acetaminophen, including the brand Tylenol, is the most frequently used drug in the world. It is an effective pain reducer and considered generally safe, but in high doses or in people with certain health conditions, it can cause serious side effects, including liver damage.

These unwanted side effects are rare if you take acetaminophen occasionally, but if you take it on a regular basis or at a higher dose than recommended, your risk increases. Overdosing on acetaminophen can be dangerous and is one of the most common causes of medication poisoning.

1. Nausea and Vomiting

One early sign of too much acetaminophen is stomach upset, including nausea and vomiting. These symptoms can show up several days after overdoing it with acetaminophen, and they mimic symptoms of “stomach flu” (viral gastroenteritis). These and other abdominal symptoms like cramps can indicate the beginning of liver damage from excess acetaminophen.

2. Sweating

Sweating can be an early sign of acetaminophen poisoning. It tends to develop within 24 hours of an overdose. The liver plays a key role in regulating body temperature. Unusual sweating, including night sweats, can be a sign of liver damage from high doses of acetaminophen, or from taking it over an extended period.

3. Itching and Rashes

Skin reactions to acetaminophen are rare, but they can occur. The Food and Drug Administration (FDA) issued a warning in 2024 about possible serious allergic responses to acetaminophen. Symptoms include:

• Hives or blisters
• Inflamed, itchy skin
• Peeling skin

The reaction can occur the first time you take acetaminophen or after you have been taking it for a while. Skin reactions can be severe and even life-threatening. If you notice any of these symptoms after taking acetaminophen, contact a healthcare provider promptly.

4. Dizziness or Confusion

Acetaminophen in large doses could lead to confusion, which can be a sign that liver damage is progressing. If your liver is not functioning well, including as a result of too much acetaminophen, it can lead to a buildup of fluid in the brain, which can cause you to feel disoriented or off-balance.

5. Anaphylactic Reaction

An anaphylactic response to acetaminophen is rare but possible. Anaphylaxis is a severe allergic reaction to a substance. It causes swelling of the face, throat, tongue, or lips. You may have trouble breathing or swallowing, go into shock, or become unresponsive.

Anaphylaxis is a life-threatening emergency. If you think you or someone else may be experiencing anaphylaxis, seek emergency medical treatment or call 911.

6. Jaundice

Jaundice is a yellowing of the skin and eyes. It is due to liver damage that causes a buildup of bilirubin, a yellow pigment produced by the breakdown of red blood cells.

You can develop jaundice from acetaminophen within three to four days of taking an excessive amount. At this stage, the pancreas may also become inflamed, and the kidneys may have difficulty working.

7. Liver Damage or Liver Failure

In the United States, acetaminophen is the cause of more than half the cases of sudden liver failure, Globally, it is the second most common cause for liver transplants.

The symptoms of serious liver damage or liver failure include:

• Diarrhea
• Distended abdomen
• Pain below your ribs on the right side
• Vomiting blood

If you are diagnosed with liver failure from acetaminophen, treatment includes activated charcoal or an antioxidant medication called N-acetylcysteine. You may also need a liver transplant.

How Much Is Too Much?

Adults should not take more than 1,000 milligrams (mg) of acetaminophen in a dose and no more than 4,000 mg within a 24-hour period unless directed by a healthcare provider.

The American College of Gastroenterology notes even healthy adults should avoid taking 3,000 mg of acetaminophen daily for more than three to five days. Your healthcare provider may recommend a lower limit based on factors such as your age and other factors, especially health conditions that affect the liver.

People with liver disease should limit acetaminophen to 2,000 mg per day, or even less, depending on the severity of their liver disease.

Many over-the-counter (OTC) products contain acetaminophen. Be sure to read the labels of any medications you take to understand the daily limits.

Acetaminophen poisoning can occur after only one dose of more than 7,500 mg in adults or 150 mg in children. If you suspect an overdose, call the Poison Control helpline at 800-222-1222 or seek prompt medical treatment.

Who Should Avoid or Use Caution With Acetaminophen?

People who have liver disease should not take acetaminophen without talking to their healthcare provider. Also, if you have three or more alcoholic drinks a day, it can increase the toxic effects of acetaminophen on the liver.

One large study in the United Kingdom showed that in people over 65, acetaminophen was associated with an increased incidence of ulcers, intestinal bleeding, heart failure, high blood pressure, and liver failure. More research is needed to confirm these associations.

A Word From Verywell

The best practice for people taking OTC medications is to understand what they are taking, why they are taking it, and what an appropriate amount is for them. If unable to determine any of these factors, contact your local pharmacist, who can help you determine the answers to these questions.

Alternatives to Acetaminophen for Pain Relief

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, Advil or Motrin (ibuprofen), and Aleve (naproxen), are a common alternative to acetaminophen for everyday pain relief from muscle aches, headaches, and fever. Keep the following in mind:

• NSAIDs are associated with gastrointestinal side effects such as nausea, ulcers, and bleeding. They also increase the risk of heart attack, stroke, and heart failure. Discuss the use of NSAIDs with a healthcare provider.
• Some products contain both an NSAID and acetaminophen, so make sure you understand what the ingredients are in the pain medication you are taking.
• All medicines can have side effects, so be cautious about what you take, how often, and how much you take.

Topical pain relievers may help with sore muscles and joints. They come in creams, lotions, and sprays that contain menthol or mild topical anesthetics.

Herbal anti-inflammatories are popular, but it is important to consider the following:

• Not enough is known about them and how they work.
• What constitutes an effective but safe dose can be unclear.
• Herbal products may still interact with other medications.
• There is a lack of regulation over herbal remedies’ manufacturing and quality control.

Heat and cold therapy may also be used for painful muscles or joints.

When to See a Provider

If you have an ongoing need for a pain reliever, see a healthcare provider to get appropriate diagnosis and treatment recommendations. They can assess whether acetaminophen is the best choice and recommend the safest dosage.

An acetaminophen overdose is serious and can be deadly. If you have been taking extra acetaminophen or taking it for a long time and have any of the symptoms discussed previously, contact a healthcare provider immediately. Effective treatment for acetaminophen side effects depends on getting quick treatment.

Summary

Acetaminophen is an ingredient in many pain relievers, including Tylenol. It’s generally a safe and effective drug, and has fewer side effects on the digestive system than NSAIDs like ibuprofen and naproxen.

However, taking too much Tylenol, whether it’s in a short period or over an extended time, can lead to serious liver damage. Rare side effects include a severe skin reaction or anaphylaxis. Be aware of how much acetaminophen is safe for you to take, and follow the recommended guidelines.