Skip to main content


Pronunciation: naar-kan
Generic name: naloxone
Dosage form: Nasal spray

Medically reviewed by Melisa Puckey, BPharm. Last updated on Mar 29, 2023.

What is Narcan?

Narcan (naloxone) nasal spray is an over-the-counter medicine used to treat an opioid overdose emergency, Narcan works by rapidly reversing the opioid's effects. Narcan should be given as soon as possible when an opioid overdose is suspected, and then the patient should also receive emergency medical care immediately, even if they wake up.

Narcan nasal spray became FDA-approved on March 29, 2023, as an over-the-counter (OTC) medicine without the need for a prescription, however it is unknown when the OTC Narcan nasal spray product will be available. Until the OTC Narcan nasal spray becomes available, Narcan nasal spray with the prescription label will still be available from a pharmacist without a prescription from your doctor, under state Naloxone Access Laws or alternate arrangements.

Narcan nasal spray can be used for adults and children for known or suspected opioid overdose if there are signs of slowed breathing, severe sleepiness, or the person is not able to respond (loss of consciousness).

Narcan works to block the opioid effect as it is an opioid antagonist. Narcan competes for the opiate receptors in the brain and other areas of the body to help reverse the dangerous effects of the opioid so that the patient's breathing improves and they become more awake, and their blood pressure normalizes.

Examples of opioids are codeine, oxycodone (Oxycontin), heroin morphine, hydrocodone (Vicodin, Lortab), fentanyl, methadone, oxymorphone, meperidine, tramadol, buprenorphine, and hydromorphone.

Narcan was originally available as Narcan injection, which has since been discontinued, the Narcan nasal spray is available as an over-the-counter medicine, so a prescription is NOT needed. 

Important information

Narcan is used to temporarily reverse the effects of opioid medicines. Narcan will have no effect in people who are not taking opioid medicines. Always carry Narcan with you in case of an opioid  overdose emergency.

Use Narcan as soon as possible if you or your caregiver think there are signs or symptoms of an opioid emergency, even if you are not sure, because an opioid emergency can cause severe injury or death. Signs and symptoms of an opioid emergency may include:

  • unusual sleepiness and you are not able to wake the person up with a loud voice or by rubbing firmly on the middle of their chest (sternum)
  • breathing problems including slow or shallow breathing in a person who is difficult to wake up or who looks like they are not breathing
  • the pupil (black circle in the center of the colored part of the eye) is very small, sometimes called "pinpoint pupils," in someone difficult to awaken.

You should know where Narcan is stored and how to give Narcan before an opioid emergency happens if you have family members, caregivers, or other people who are at risk of opioid overdose and may need to have Narcan administered in an opioid emergency.

After giving the first dose of Narcan you need to get emergency medical help right away, even if the person wakes up. Rescue breathing or CPR (cardiopulmonary resuscitation) may be given while waiting for emergency medical help

The signs and symptoms of an opioid emergency can return after Narcan is given. If this happens, give another dose after 2 to 3 minutes using a new Narcan nasal spray and watch the person closely until emergency help is received.

Before taking this medicine

You should not be treated with Narcan if you are allergic to naloxone or any of the ingredients in Narcan. See the bottom of this document for a complete list of ingredients in Narcan nasal spray.

If possible before you receive Narcan, tell your doctor if:

  • you have heart problems; or
  • you are pregnant or breastfeeding.

If you use opioid medicine during pregnancy, your baby could be born with life-threatening withdrawal symptoms, and may need medical treatment for several weeks.

Using Narcan while you are pregnant may also cause opioid withdrawal effects in your unborn baby. However, having an opioid overdose can be fatal to both mother and baby. It is much more important to treat an overdose in the mother. You must get emergency medical help after using this medicine. Be sure all emergency medical caregivers know that you are pregnant.

If you use opioid medicine while you are pregnant, your baby could become dependent on the drug. This can cause life-threatening withdrawal symptoms in the baby after it is born. Babies born dependent on opioids may need medical treatment for several weeks.

In an emergency, you may not be able to tell caregivers if you are pregnant or breastfeeding. Make sure any doctor caring for your pregnancy or your baby knows you received Narcan.

How should I use Narcan?

Use this medicine exactly as prescribed by your healthcare provider.
  • Each Narcan nasal spray contains only one dose of medicine and cannot be reused.
  • Narcan is available in a 2 mg and 4 mg strength. Your healthcare provider will prescribe the strength that is right for you.
  • Remove Narcan from the box. Peel back the tab with the circle to open the Narcan nasal spray.
  • Do not prime Narcan nasal spray.
  • Lay the person on their back with their neck supported with your hand and allow the head to tilt back before giving Narcan nasal spray.
  • Hold the Narcan with your thumb on the bottom of the red plunger and your first and middle fingers on either side of the nozzle.
  • Gently insert the tip of the nozzle into one nostril until your fingers on either side of the nozzle are against the bottom of the person's nose.
  • Press the red plunger firmly to administer the dose of Narcan.
  • Remove the Narcan from the nostril after giving the dose.
  • You must get emergency help immediately after giving Narcan.
  • After giving this medicine, stay with the person and watch for continued signs of overdose. You may need to give another dose every 2 to 3 minutes until emergency help arrives. If another dose is needed, give Narcan in the other nostril from a new Narcan nasal spray.
  • Do not assume that an overdose episode has ended if symptoms improve. You may need to perform CPR (cardiopulmonary resuscitation) on the person while you are waiting for emergency help to arrive.

Narcan training video

For more detailed instructions (with pictures) about the right way to use Narcan, read the "Instructions for Use" at the bottom of the Professional Narcan document.

Dosing information

Usual Adult and Pediatric Dose for Opioid Overdose:

Administer 1 spray intranasally into 1 nostril

If desired response is not achieved after 2 or 3 minutes, give a second dose from a new Narcan, intranasally into alternate nostril; additional doses may be administered every 2 to 3 minutes in alternating nostrils until emergency medical assistance arrives.


  • IV route is recommended in emergency situations since it has the most rapid onset of action.
  • The duration of action of some opioids exceed that of this drug, therefore, repeat doses may be needed; the need for repeat doses will depend on the amount, type, and route of administration of the opioid being antagonized.
  • Patients should remain under continued surveillance; if a patients responds and relapses back into respiratory depression, additional doses should be given.
  • Additional supportive and/or resuscitative measures may be helpful while awaiting emergency medical assistance.

What should I avoid while taking Narcan?

Avoid leaving a person alone after giving him or her a dose of Narcan. An overdose of naloxone can impair a person's thinking or reactions.

Narcan side effects

Get emergency medical help if you have signs of an allergic reaction to Narcan: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Because Narcan reverses opioid effects, its use may cause sudden withdrawal symptoms such as:

  • nausea, vomiting, diarrhea, stomach pain;
  • fever, sweating, body aches, weakness;
  • tremors or shivering, fast heart rate, pounding heartbeats, increased blood pressure;
  • goose bumps, shivering;
  • runny nose, yawning; or
  • feeling nervous, restless, or irritable.

Sudden withdrawal symptoms in a baby younger than 4 weeks old may be life-threatening if not treated the right way. Symptoms include crying, stiffness, overactive reflexes, and seizures. Call your doctor or get emergency medical help if you are not sure how to properly give this medicine to a baby.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Narcan?

Other drugs may interact with naloxone, including prescription and over-the-counter medicines, vitamins, recreational drugs and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.


  • Narcan should be stored below 77°F (25°C) with excursions permitted up to 104°F (40°C).
  • Do not freeze Narcan or expose it to excessive heat above 104°F (40°C).
  • Keep Narcan in its box until ready to use. Protect from light.
  • Replace Narcan before the expiration date on the box.
  • Keep this medicine  and all medicines out of the reach of children.

What are the ingredients in Narcan?

Active ingredient: naloxone hydrochloride

Inactive ingredients: benzalkonium chloride (preservative), disodium ethylenediaminetetraacetate (stabilizer), sodium chloride, hydrochloric acid to adjust pH and sterile water

Narcan is not made with natural rubber latex.


Narcan Nasal Spray is Distributed by Emergent Devices Inc., Plymouth Meeting, PA 19462 USA.

For more information, go to or call 1-844-4Narcan (1-844-462-7226).

Popular FAQ

Is naloxone a controlled substance?

Naloxone is not a controlled substance, according to the US Drug Enforcement Administration (DEA). It is an opioid antagonist used to treat known or suspected opioid overdose, and naloxone nasal spray (sold under the brand name, Narcan) was FDA-approved for sale over-the-counter on March 29th, 2023. It should be available for purchase in places like drug stores, convenience stores, grocery stores and gas stations, as well as online, without a prescription from late summer. Narcan Nasal Spray and naloxone is still available from the pharmacist in all 50 states without a prescription from your doctor.

Is naloxone an opioid antagonist?

Naloxone is a centrally acting opioid receptor antagonist. Naloxone binds with the highest affinity to the mu-opioid receptor subtype in the central nervous system (CNS). Naloxone works to reverse opioid overdose and a form of naloxone (Narcan nasal spray) was FDA-approved for over-the-counter (OTC) sale on 29th March 2023.

There are several ways to get free Narcan (naloxone) emergency kits, which include, local syringe exchange programs, your insurance company, and state and local health departments or other community health services. Continue reading

Naloxone blocks opioid receptors from 30 to 120 minutes, but this can be variable and depends upon the dose and how it is given. Some patients may need repeat doses of naloxone. Continue reading

Buprenorphine and naloxone is a combination medicine used for the maintenance treatment of opioid dependence in adults. It is available in sublingual film and sublingual tablet dosage forms under the brand names Suboxone, Zubsolv, Bunavail (discontinued), and Cassipa (discontinued). Continue reading

More FAQ

View more FAQ

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.