Substance guides

Complete naloxone guide: How to save a life

Published March 18, 2025 · 7 min read · Updated April 2026
Reviewed for accuracy by licensed clinical professionals.

Naloxone (brand name Narcan) reverses opioid overdose within minutes. It is safe, effective, and available without a prescription.

How it works

Naloxone blocks opioid receptors, reversing respiratory depression (the mechanism of overdose death). It works within 2-5 minutes. It wears off in 30-90 minutes (the person may re-overdose if the opioid outlasts naloxone).

How to administer

Nasal spray: insert into one nostril, press plunger firmly. If no response in 2-3 minutes, give second dose in other nostril. Intramuscular injection: inject into outer thigh or upper arm through clothing if necessary.

After administering

Call 911 immediately. Place person in recovery position (on their side). Stay until emergency services arrive. Be prepared: the person may wake up confused, agitated, or in withdrawal. Do NOT let them leave, as the opioid may outlast the naloxone.

Authoritative sources

This article references guidelines from: SAMHSA · NIDA · ASAM

Frequently asked questions

How do I find help?
Call SAMHSA at 1-800-662-4357 or search our directory.
Is treatment effective?
Yes. Evidence-based treatment works.
Does insurance cover this?
Yes under the Mental Health Parity Act.

Disclaimer: Informational only. Not medical advice. SAMHSA: 1-800-662-4357.

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