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Learn About Naloxone

Learn about naloxone, compare products, and read the latest research about naloxone.

What is Naloxone?

Naloxone is a medicine that temporarily stops the effect of opioids. This helps a person start to breathe again and wake up from an opioid overdose. Naloxone (the generic name) is also sold under the brand names Narcan®.


  • only works on opioids; it has no effect on someone who has not taken opioids.
  • cannot be used to get high and is not addictive.
  • has a long safety history; adverse side effects are rare.
  • can be easily and safely administered by laypersons.

In WA State, anyone who might have or witness an opioid overdose can legally possess and administer naloxone.

How Naloxone Works

Naloxone attaches to the same brain receptors as opioids, but more
strongly. Naloxone kicks off the opioids and “takes over” the receptors, causing opioid withdrawal. This restores breathing and consciousness in about 2-5 minutes.

When naloxone wears off in about 30-90 minutes, any opioids still in the brain can return to the receptors. The person may stop breathing again.

Naloxone will not reverse the effects of other drugs like cocaine, methamphetamine, alcohol, or benzodiazepines (e.g. Xanax®, Klonopin® and Valium®). But naloxone can still block the effect of opioids (and reverse the overdose) even if the person has also taken one or more of these other drugs.

Naloxone is very safe and easy to use. Bad reactions to naloxone are rare and it is safe to give to anyone, including children and pregnant women. When naloxone is used on a pregnant woman, there is a risk from miscarriage due to opioid withdrawal. Pregnant women who have overdosed should get medical help right away.

When someone wakes up after naloxone, they may feel some symptoms of opioid withdrawal like pain, sweating, nausea, or vomiting. The person may also feel confused, anxious or slightly agitated. Rarely are people combative or violent.

illustration of naloxone receptors in brain

Naloxone Products

Naloxone can be sprayed into the nose or injected into a thick muscle like the thigh or upper arm. These are the two types of naloxone currently available; click each one to learn more about it.

All of the naloxone products available are similarly effective against opioid overdose. A health care provider or pharmacist can help you select which product is best for you.

What about high dose naloxone products?

The Washington Department of Health does not recommend the routine use of higher dose naloxone formulations (e.g., 5 mg or more) because of the risks of precipitating acute withdrawal symptoms in people who are opioid dependent” from the WA DOH Naloxone Standing Order FAQ.

More information:

The shelf life for Narcan Nasal Spray has been extended from 24 to 36 months. This does not apply to kits retroactively.

Naloxone Laws in WA State

Several laws in WA State allow lay persons to possess and administer naloxone and provide immunity from liability when assisting in an overdose.

Possessing, Using and Distributing Naloxone

WA State law RCW 69.41.095 allows anyone “at risk for having or witnessing a drug overdose” to obtain an opioid overdose medication and administer it in an overdose. This includes people who use opioids, family members, friends and professionals. WA State’s 2015 “Naloxone law” RCW 69.41.095 also permits naloxone to be prescribed directly to an “entity” such as a police department, homeless shelter or social service agency for staff to administer if they witness an overdose when performing their professional duties.

RCW 69.41.095 permits non-medical persons to distribute naloxone under a prescriber’s standing order.

Immunity from Liability

Several laws in WA State (commonly called “Good Samaritan” laws) give certain protections to laypersons trying to assist in a medical emergency. RCW 4.24.300 provides immunity from civil liabilities when responding in a medical emergency. RCW 69.50.315 further protects both the overdose victim and the person assisting in an overdose from prosecution for drug possession.

Statewide Standing Order

Under the WA Statewide Standing Order anyone can go to a pharmacy that carries naloxone and obtain it without a prescription from their healthcare provider. Organizations can use the standing order to purchase naloxone to have on-site or for distribution.

Over-the-Counter (OTC) naloxone

OTC naloxone products have been approved by the FDA, and OTC naloxone (Narcan Nasal Spray) is now available in many pharmacies. Learn more here.

Life Insurance Companies and Naloxone in Washington State

On August 2, 2022 the State of Washington Office of Insurance Commissioner issued a memo clarifying that “In the case of opioid reversal medication [naloxone], neither coverage nor underwriting decisions can legitimately be based” on whether someone has a prescription for naloxone. “Therefore, decisions to deny coverage or charge higher premiums based solely on the presence of such a prescription would violate RCW 48.18.480 and 48.30.300.”

Read the memo here.

Naloxone Expiration Dates

Naloxone products typically have an expiration date (“shelf life”) approximately 18-24 months from the date of manufacture. Expiration dates are based on how long a manufacturer guarantees the full potency and safety of a drug.

Two peer reviewed articles have tested the stability of naloxone:

2006 article examined the stability of an array of medications based upon the Shelf Life Extension Program which “…is administered by the FDA for the U.S. DOD [Department of Defense] and … the Strategic National Stockpile…” and  found that “top performers from this group were naloxone HCl (all 10 lots extended at least 5 years).”

2019 study based on naloxone “collected from EMS or law enforcement training supplies and expired returns, with expiration dates ranging from 1990 to 2018.” Found that “Most tested samples were found containing more than 90% of labeled naloxone, including those stored for nearly 30 years.”

The 2019 naloxone training video  from Washington State’s Department of Health  says that “Naloxone can work past its expiration date, but works best when not expired.” Naloxone should be stored properly, protected from sunlight and temperature extremes.

Based on these studies it appears that naloxone products may be effective many years after the printed expiration date.

The Network for Public Health Law has a fact sheet The Legality of Dispensing Expired Naloxone in Washington: “We conclude that, while certain regulations prohibit some health-related organizations from distributing expired medications, no laws prohibit the distribution of expired naloxone by harm reduction organizations and similar entities.

Support for Take-home Naloxone

A number of governmental and professional organizations have endorsed policies to expand opioid overdose education and availability of take-home naloxone:

Research on Overdose Education and Naloxone

There is a growing body of research evidence that shows overdose education and naloxone distribution are:


Cost effective:

Improve knowledge and skills to prevent overdose deaths:

Reduce overdoses in communities:

Do not increase drug use:


Systematic Reviews


Other Resources for Research Summaries