Substance guides

How long does it take to detox from opioids?

Published May 18, 2025 · 6 min read · Updated April 2026

Reviewed for accuracy by licensed clinical professionals.

Opioid detox duration depends on which opioid was used and whether MAT is incorporated.

Short-acting opioids (heroin, oxycodone)

Without MAT: 5-7 days of acute withdrawal. Onset at 8-12 hours. Peak at 36-72 hours. With MAT (buprenorphine): withdrawal is essentially eliminated. Stabilization in 1-3 days.

Long-acting opioids (methadone)

Without MAT: 2-3 weeks of withdrawal. Onset at 24-36 hours. Peak at days 3-5. Prolonged discomfort. With MAT: transition to buprenorphine requires careful management.

Fentanyl

Unpredictable timeline due to fat storage. May have recurring withdrawal symptoms over 1-2 weeks. Micro-dosing buprenorphine protocols increasingly used.

Post-acute withdrawal

After acute detox, post-acute symptoms (insomnia, anxiety, depression) may persist for weeks to months regardless of the specific opioid.

Authoritative sources

This article references guidelines from: NIDA · SAMHSA · CDC

Frequently asked questions

How long does opioid detox take?

Short-acting: 5-7 days. Long-acting: 2-3 weeks. MAT eliminates acute withdrawal within 1-3 days.

Is opioid detox dangerous?

Rarely directly life-threatening but severe dehydration can be dangerous. MAT is strongly recommended.

What is the fastest way to detox from opioids?

MAT with buprenorphine eliminates withdrawal within hours to days. Without medication, acute symptoms last 5-7 days.

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