How Long Does Norco Stay in Your System?

Norco in Your Blood, Urine, Hair, & Saliva

Norco is the brand name for a prescription medication that combines hydrocodone, an opioid pain reliever, with acetaminophen. Acetaminophen is an over-the-counter (OTC) non-opioid pain reliever. It's often sold under the brand name Tylenol and also is a common active ingredient in OTC cough, cold, and fever medications.

There are quite a few prescription pain relievers that have these same two components. One of the most familiar is Vicodin; other hydrocodone/acetaminophen combination drugs include Anexsia, Lorcet, and Lortab.

The main difference between most of these medications is the amounts of hydrocodone and acetaminophen. They're all prescribed to treat moderate to severe pain. All versions of Norco come as a tablet.

Combination drugs with less than 15 milligrams of hydrocodone per dose unit like Norco are classified as Schedule II substances, meaning they are considered to have a high potential for misuse, with use potentially leading to severe psychological or physical dependence.

Norco Detection Times
Verywell / Gary Ferster  

How Long Does It Take to Feel the Effects?

Norco is taken orally in tablet form and the drug must pass through the digestive system before it begins to take effect. The acetaminophen in Norco tends to be rapidly absorbed in the gastrointestinal tract and begins to take effect within 10 to 30 minutes of ingestion.

The hydrocodone component of Norco is slower-acting but begins to relieve pain about 30 to 60 minutes after ingestion. The pain-relieving effects of Norco typically last between four and eight hours.

Common side effects of Norco include:

  • Constipation
  • Dizziness
  • Drowsiness
  • Headache
  • Nausea
  • Stomach pain
  • Vomiting

When taken in large doses or misused, Norco can cause the following side effects:

  • Acute abdominal conditions
  • Head injury and increased intracranial pressure
  • Respiratory depression

How Long Does Norco Last?

When talking about how long a particular medication remains active in the body it helps to understand the concept of half-life. Half-life refers to the amount of time it takes for half of the dose of a particular drug to be eliminated from the body. 

For Norco, of course, it's necessary to consider both the half-life of hydrocodone and the half-life of acetaminophen. The half-life of hydrocodone is about four hours. After five or six half-lives, the drug has been mostly eliminated from your system.

However, it is important to note that even at this point, hydrocodone can be detected in the urine for up to three days. This means that if you take a urine drug screen after being on Norco, it is likely to test positive for opiates even if your last dose was days earlier.

Hydrocodone is metabolized by the liver into its major metabolites hydromorphone and dihydrocodeine. Around 85% of an oral dose is excreted through the urine within 24 hours, mostly in the form of glucuronide conjugate, other conjugates, and small amounts of the unchanged drug.

The acetaminophen in Norco has a half-life in the blood of an hour and 15 minutes to three hours. Acetaminophen is rapidly absorbed in the gastrointestinal tract, eliminated primarily by the liver, and later excreted by the kidney as metabolites. Most acetaminophen has passed out of the body through the urine after 24 hours.


Because urine tests are sometimes susceptible to false positives, a positive test for opioid use on a standard drug screen may be followed up with a blood test to confirm the results. However, the detection window in blood is much shorter.

Norco may be detectable by a blood test for up to 24 hours after ingesting the last dose. While blood tests provide greater accuracy, they are also much more invasive and costly. Because of this, this type of testing is not often used in occupational settings but is more common in forensic and legal contexts.


Hair testing can detect Norco metabolites in hair follicle samples for up to 90 days after the last dose. While such testing can be effective at detecting the past use of a drug, it can also be more costly. It may be used in instances where employers or law enforcement are looking at past drug use or misuse.


Due to its hydrocodone contents, Norco may be detectable in saliva for up to three days after ingestion. While saliva testing has some advantages, including being fairly easy to administer and non-invasive, the small specimen size can present testing challenges.


Norco may be detectable in the urine for up to three days after taking a dose. Urine tests are among the most common types of drug tests because they are less invasive, less expensive, and are easy to administer. If you have been taking Norco, you may test positive for opioids on a standard immunoassay urine drug screening.

You should inform the lab that you have been taking this prescription medication for pain management so that they are able to interpret your results accurately.

Factors That Affect Detection Time

A number of different individual factors can play a role in how long Norco remains detectable in the body. Such factors include:

  • Alcohol use: Ingesting other substances at the same time can make it more difficult for the body to process and clear Norco from your system.
  • Age: Older adults tend to clear the drug more slowly than younger adults.
  • Dosage: Taking a higher dose of the substance means that it will take longer to process and excrete the drug.
  • Frequency: If you have been taking Norco for a while, it will take longer for the drug to completely clear your system.
  • Hydration: Taking in more fluids can dilute the amount of the drug present in urine samples, making it more difficult to detect.
  • Liver function: Because the liver is important in the metabolism of the drug, impaired liver function can mean that it takes longer to metabolize Norco.
  • Metabolism: People with slower metabolisms may clear the drug at a slower rate.
  • Weight: People who are taller and heavier may metabolize the drug more quickly, while people who are shorter and lighter may process the substance at a slightly slower rate.

It's important to know how long a medication like Norco stays in the body since substances such as alcohol as well as other medications can lead to potentially dangerous interactions with either hydrocodone or acetaminophen. This information also is vital for preventing overdoses of either ingredient.

For example, if you were to take significant amounts of Tylenol or an OTC cold or cough medication containing acetaminophen before Norco has cleared from your system, you potentially could wind up with an overdose of acetaminophen in your body—a situation that has been found to lead to severe liver damage, according to the Food and Drug Administration (FDA).

Understanding how long Norco remains active in the body and when it will clear can help you and your doctor time your doses so that you get the most benefit without the risk of side effects.

How to Get Norco Out of Your System

The only surefire way to get Norco out of your system is to stop taking the drug and give your body time to eliminate it; exercising or drinking a lot of water will not flush the drug out of your system. To avoid unpleasant withdrawal symptoms, work with your doctor to taper off the medication slowly.

Symptoms of Overdose

Knowing how long Norco remains in the system also can help prevent an accidental overdose caused by taking too much of the medication too soon. The following are some of the signs and symptoms of a Norco overdose:

  • Bluish-colored fingernails and lips
  • Breathing problems
  • Cold, clammy skin
  • Coma
  • Confusion
  • Dizziness
  • Drowsiness
  • Fatigue
  • Lightheadedness
  • Loss of consciousness
  • Low blood pressure
  • Muscle twitches
  • Pinpoint pupils
  • Seizures
  • Spasms of the stomach and intestines
  • Weakness
  • Weak pulse

If you or someone you're caring for is taking Norco and experiences any of these symptoms, call 911.

In the event the overdose has caused loss of consciousness, first responders can administer a drug called Narcan (naloxone) to counteract the effects of the hydrocodone.

Dangerous Drug Interactions

Because hydrocodone is an opiate narcotic, it brings a risk of dangerous interactions with a number of different substances, including alcohol and other drugs.

Drinking while taking Norco can lead to serious side effects caused by either the combination of alcohol with hydrocodone or the combination of alcohol with acetaminophen, according to the National Institute on Alcohol Abuse and Alcoholism.

Alcohol Risks With Norco

  • Alcohol and hydrocodone can cause drowsiness, dizziness, an increased risk of overdose, breathing problems, impaired motor control, unusual behavior, and memory problems.
  • Alcohol plus acetaminophen can lead to stomach problems and liver damage.

Liver damage caused by acetaminophen is a particularly serious problem. That may seem odd since Tylenol and other over-the-counter medications containing acetaminophen are so accessible, but that's part of the problem.

People often will unknowingly take more than one medication containing acetaminophen at a time. Research has found that exceeding 4,000 milligrams (mg) a day can lead to potentially irreversible and even fatal liver damage.

Accidental overdoses and even deaths may occur in this scenario. For that reason, any medication that combines acetaminophen with another ingredient can have only 325 mg of acetaminophen.

Norco, for example, comes in several strengths of hydrocodone, ranging from 2.5 mg to 10 mg, but all of these versions have only 325 mg of acetaminophen. Of the medications that can cause problems when taken while Norco is in your system, the ones that are most dangerous are those that can interact with hydrocodone, particularly benzodiazepines.

Examples include:

These are prescription depressant drugs used most often to treat anxiety, muscle spasms, and seizures. 

The potential dangers of mixing hydrocodone with a benzodiazepine medication are so potentially serious that ​an August 2016 review by the FDA resulted in the addition of boxed warnings on both types of drugs about the risks of mixing them, including slowed or difficult breathing and even death.

Other types of medications that can interact with Norco include:

  • Muscle relaxants
  • Sedatives
  • Sleeping pills
  • Tranquilizers
  • Certain treatments for mental illness or nausea

The best way to protect yourself from harm while taking Norco is to make sure your doctor knows about all drugs and supplements you are taking before you begin treatment.

Getting Help

Like other opioids, the hydrocodone content of Norco can lead to tolerance and physical dependence, even if you take them exactly as prescribed. Tolerance means that people require larger doses of the drug to feel the same pain-relieving effects. If this happens, you should talk to your doctor.

Never take a larger dose than what you have been prescribed. Your doctor may adjust your dose or switch you to another type of medication.

Physical dependence occurs when the body becomes accustomed to the presence of a substance.

When a person develops a dependence on a drug, they need to continue taking it in order to avoid experiencing symptoms of withdrawal.

When you decide to stop taking Norco or another type of opioid medication, your doctor may gradually lower your dose in a process called tapering in order to avoid withdrawal effects.

Symptoms of Norco withdrawal can include:

  • Anxiety
  • Chills
  • Diarrhea
  • Fatigue
  • Headaches
  • Muscle aches
  • Runny nose
  • Sweating
  • Vomiting

Such symptoms typically last for five to seven days, but your doctor can prescribe medications that will help you cope during the withdrawal period. If you suspect that you might be dependent or addicted to Norco or another hydrocodone-containing medication, help is available.

Start by talking to your doctor, who can help you taper off the drug and find another medication that will alleviate your pain. Your doctor may also recommend inpatient or outpatient residential treatment or refer you to a mental health professional who specializes in addiction treatment and recovery.

If you or a loved one are struggling with substance use or addiction, contact the Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline at 1-800-662-4357 for information on support and treatment facilities in your area. 

For more mental health resources, see our National Helpline Database.

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Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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