How long does 500mg of acetaminophen stay in your system

More than 1,000 medications have been identified as being potentially toxic to the liver. But there is one medication that causes more cases of acute liver injury than any other in the U.S., and it is likely in your medicine cabinet. The drug is acetaminophen, the analgesic and fever reducer found in Tylenol, NyQuil and more than 600 over-the-counter and prescription medications.

“Approximately 30 to 50 percent of hospitalizations from acetaminophen come from unintentional overdoses,” said Jeffrey Yin, PharmD, a pharmacist at UC San Diego Health who works with patients with liver disease.

The problem is the medication’s ubiquity, he said. Cold, flu and allergy medications, sleep aides, as well as medications for headaches, arthritis and pain, may contain acetaminophen. The Liver Foundation lists acetaminophen as the most common drug ingredient in the U.S.

“Because it is embedded in so many products, it is easy for people to accidentally double-up on acetaminophen-containing products,” Yin said. Liquid medications also pose an opportunity for accidental overdose, as people may make a mistake measuring out a dose or simply take a swig.

For people who do not have chronic liver disease and do not drink three or more alcoholic beverages a day, the recommended oral dose of acetaminophen is 660 to 1,000 mg every four to six hours, not to exceed three grams per day.

To appreciate how easy it is to exceed the safe limit, consider that one extra strength Tylenol tablet contains 500 mg of acetaminophen. Take two tablets at a single dose three times a day and you are at the maximum recommended dose. If you then inadvertently consume an acetaminophen-containing allergy medication or cold medication in addition, you risk damaging your liver, Yin said.

The key is to be aware of how much acetaminophen you are consuming. Yin recommends that consumers look at all the medications they are taking, and tally up the total amount of acetaminophen consumed on an average daily basis to make sure the total dose is under the three-gram-a-day limit.

It is better to err on the side of caution. Yin recommends looking for opportunities to reduce drug intake when possible. “Avoid taking combination products, if you don’t have all the symptoms it is intended to treat,” he said. For example, if a cold or flu product is meant to treat fevers, runny noses and congestion, but you only have a runny nose, choose a product that only treats the runny nose, rather than the combination product.

“I have patients who take Tylenol PM to help them sleep even though they have no pain issues,” Yin said. “They are consuming acetaminophen for no therapeutic benefit. I recommend opting instead for an acetaminophen-free sleep aide.”

Drinking alcoholic beverages should also be avoided. “People who drink even a moderate amount should talk with their doctor before taking acetaminophen,” Yin said. “Alcohol and acetaminophen can be a dangerous combination.”

Beyond acetaminophen and alcohol, there are other potentially liver-injuring drugs and supplements that should be used with caution, including:

• Certain antibiotics, such as rifampin for tuberculosis
• Psychedelic (“magic”) mushrooms, such as those containing psilocybin
• Herbal products, notably St. John’s Wort and kava kava

“I have patients who want to take herbal products and think they are safer than medications,” Yin said. “But this is not always true. Plants produce many chemicals that interact in ways we don’t understand in the body. A medication is formulated to contain one compound at a standardized dose, making its efficacy and safety more predictable.”

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Tylenol #3, also known as Tylenol with codeine, is a prescription version of the same Tylenol that's available over the counter at the drugstore. You've probably reached for Tylenol (or its generic version, acetaminophen) more than once to treat a headache, ease muscle soreness after a tough workout, or bring down a fever.

The addition of codeine, a prescription analgesic (pain reliever) that works on the central nervous system, is the reason Tylenol #3 is available only by prescription. Codeine is an opiate (aka narcotic), and as such can be habit-forming if not taken exactly as directed by a doctor.

Because of its high potential for misuse and physical dependence, codeine is classified as a Schedule II, III, IV, and V drug, depending on its formulation and use. Drugs containing less than 90 milligrams of codeine per dosage unit, which includes Tylenol #3, are classified as Schedule III drugs.

Both acetaminophen and codeine have risks for serious interactions with other medications and overdoses. If you know more about how long Tylenol #3 stays in your body, you may better understand how to avoid these reactions.

How Long Does Tylenol #3 Stay in Your System?

Urine: Up to three days

Blood: Up to 24 hours

Saliva: Up to four days

Hair: Up to 90 days

How Long Does It Take to Feel Effects?

After ingestion, it usually takes about an hour to begin feeling the pain-relieving effects of Tylenol #3, which can last roughly three to four hours, depending on your dosage.

Codeine is metabolized by the body into morphine. At higher doses, morphine and other opioids can cause feelings of elation, analgesia, and euphoria as well as dangerous side effects, including stopping of the heart and brain damage.

Common side effects of codeine include:

• Constipation
• Difficulty urinating
• Drowsiness
• Headache
• Lightheadedness
• Mood changes
• Stomach pain

Common side effects of acetaminophen include:

• Headache
• Nausea

In rare cases, acetaminophen can cause a severe skin reaction that can be fatal. Call your doctor immediately if you experience any of the following side effects:

• A rash that spreads and causes blistering and peeling
• Clay-colored stools
• Confusion
• Dark urine
• Itching
• Jaundice
• Light-headedness (like you're going to pass out)
• Loss of appetite
• Nausea
• Noising breathing
• Severe dizziness
• Shallow breathing
• Skin redness
• Upper stomach pain
• Yellowing of the skin or eyes

How Long Does Tylenol #3 Last?

The half-life of a medication is the time it takes for the drug to decrease to half of its original concentration, or put another way, the time it takes for half of a dose to be eliminated from the body. The half-lives of the components of Tylenol #3 are slightly different:

• Acetaminophen: Each Tylenol #3 tablet contains 300 milligrams of acetaminophen. For most people, this amount of Tylenol has a half-life in the blood of 1.25 to 3 hours. All of the drug will have passed out through the urine within 24 hours. Note that this could take longer in someone who has a poor liver function.
• Codeine:There is 30 milligrams of codeine in a single Tylenol #3 tablet. Codeine takes longer to clear from the system than acetaminophen. Typically, codeine has a half-life of 2.5 to three hours and it can continue to work in the body for four to six hours. Codeine continues to show up in urine for as many as three days after being taken.

Urine

Urine screenings, which are the most commonly used drug tests because they are relatively easy and cost-effective to administer, can detect the codeine in Tylenol #3 in your system for up to three days after use. 

Blood

Blood tests, which are used less frequently because they are more invasive and costly than urine tests, have a 24-hour window for detecting the codeine in Tylenol #3. 

Saliva

Codeine in Tylenol #3 is detectable in oral fluid taken in saliva testing for up to four days after ingestion.  

Hair

Codeine use can be detected by a hair follicle test for a longer period—up to three months. 

False Positive Testing

If you consume just one poppy seed muffin or two poppy seed bagels, it can trigger a false-positive test result for opiates. Poppy seeds contain trace amounts of codeine.

Certain medications, including certain allergy and cold medications (diphenhydramine), sleep aids (doxylamine), and medications to treat hypertension (Verapamil), have been found to cause false-positives for opiates on enzyme immunoassay (EIA) drug tests as well.

It's important to let the lab clinician know if you have eaten anything or taken any medications or supplements that might affect your results.

Factors That Affect Detection Time

How long Tylenol #3 is detectable in your body depends on a variety of factors, including the dosage and how often you use the medication as well as your weight, age, metabolism, and overall health.

Age

Older adults tend to clear the drug at a slower pace than younger adults.

Metabolism

Your metabolic rate, which can be influenced by age, activity level, and overall health, influences the detection time of Tylenol #3. In general, the slower your metabolism, the longer the drug will remain in your system.

Overall Health

Because the liver and kidneys both play a role in the metabolism of the drug, impaired liver and kidney function can mean that it takes longer to metabolize Tylenol #3.

Frequency & Dosage

A higher dose of Tylenol #3 will take longer to process and excrete than a lower dose. Similarly, if you've been taking the drug for some time, it will take longer to clear your system.

How to Get Tylenol #3 Out of Your System

Like other drugs, the best way to get Tylenol #3 out of your system is to stop using the drug and give your body time to process and eliminate it. Staying well-hydrated and getting regular exercise can't hurt but this doesn't mean that sweating out or flushing out the drug with tons of water will help. This method will only dilute the drug test and you'll likely have to retake it.

If you plan to stop using the drug, work with your doctor. It's best to taper off of prescriptions containing codeine in order to avoid unpleasant withdrawal symptoms.

Symptoms of Overdose

Codeine also can be extremely dangerous if there's too much of the drug in the body at once, whether it's taken alone or as an active ingredient in Tylenol #3. The same may be true of acetaminophen even though it's a non-narcotic pain reliever, but for different reasons.

If you take the medication exactly as your doctor prescribed and you're careful to not take another drug that could interact with acetaminophen or codeine, you shouldn't have any problems taking Tylenol #3.

Still, it's good to be aware of the following symptoms of a potential overdose:

• Bluish lips or skin under fingernails
• Cold, clammy skin
• Coma
• Convulsions
• Drowsiness
• Heavy sweating
• Low blood pressure
• Pinpoint pupils
• Respiratory arrest
• Slow, shallow, labored breathing
• Stupor (lack of alertness)

Symptoms of Tylenol #3 overdose may not be evident right away, but may include:

• Abdominal pain
• Nausea
• Vomiting

If you suspect that you or a loved one may be experiencing an overdose, call 911 or seek medical help immediately.

Dangerous Interactions

Acetaminophen has a narrow safety range. If you take more than 4,000 milligrams per day, you risk irreversible liver damage that ultimately can lead to death.

Damage and overdose can happen more easily than you might think because acetaminophen is an ingredient in many different combination medications, such as cold or allergy drugs designed to target multiple symptoms.

For this reason, combination medications like Tylenol #3 are limited to no more than 325 milligrams of acetaminophen per tablet, capsule, or other dosage unit. Before you take another medication, read the ingredient list carefully. If the medication contains acetaminophen (or paracetamol as it's known in Europe and the UK), note how many milligrams there are per dose.

Do the math to make sure you don't exceed 4,000 milligrams in a 24-hour period. Safer yet, talk to your doctor or pharmacist before taking Tylenol #3 and another product containing acetaminophen.

Codeine may also cause serious breathing problems in some individuals, especially during the first day or two of taking it. In fact, it's generally recommended that people who have conditions such as asthma or chronic obstructive pulmonary disease (COPD) use codeine with significant caution.

Codeine can interact with other medications and substances, too. Because it affects the central nervous system, you should be careful not to take other drugs that can slow breathing or cause drowsiness while taking Tylenol #3, or before it's likely to have cleared from your system.

Do not drink alcohol while using Tylenol #3. Also, you shouldn't take other medications that contain acetaminophen or that might have sedative properties, including:

• Cold or allergy medicines
• Pain relievers
• Sleeping pills
• Tranquilizers

Tell your doctor about all prescription, non-prescription, and over-the-counter medications you're taking so they can check for interactions and adjust dosages as needed.

Getting Help

Having too much codeine in the body poses several risks. For one, the drug can be habit-forming, meaning it could cause a person to develop a dependence.

If you've been taking Tylenol #3 for several weeks or longer and want to stop, talk to your doctor. They can help you taper off the drug safely by decreasing your dose slowly.

Withdrawal

Suddenly stopping the medication may lead to withdrawal symptoms, including: 

• Restlessness
• Widened pupils (black circles in the center of the eyes)
• Teary eyes
• Irritability
• Anxiety
• Runny nose
• Difficulty falling asleep
• Staying asleep
• Yawning
• Sweating
• Fast breathing
• Fast heartbeat
• Chills
• Nausea
• Loss of appetite
• Vomiting
• Diarrhea
• Stomach cramps
• Muscle aches

A Word From Verywell

Even when taken as prescribed, codeine in Tylenol #3 has a high risk of dependence. If you think you are becoming dependent on the drug, talk to your doctor about treatment options, which may include medications to relieve withdrawal symptoms. Your doctor can also refer you to a mental health professional or addiction treatment facility for longer-term treatment and support.

How long does acetaminophen last for?

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