Fentanyl Withdrawal Timeline

Fentanyl withdrawal timeline at a glance

When did you last use or take it?

⚠ Medical warning (read before using this)

Don’t go through opioid withdrawal alone. It is very hard to get through, and the biggest danger comes afterward: once your tolerance drops, using your old amount can cause a fatal overdose. Get medical help to stop. Medicines such as buprenorphine and methadone work. Call SAMHSA at 1-800-662-4357, or 911 in an emergency. If the opioid is prescribed, don’t stop it suddenly: ask your prescriber about a taper.

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This places the typical ranges from this article's sources on your date. It is not a prediction or a diagnosis, and being past a phase does not mean symptoms or risks are over.

A rough guide from published sources, not medical advice. Everyone is different.

Phase	When	What you may feel	Severity	Red flags
Early withdrawal	8 to 24 hours after last use	Watery eyes, runny nose; Sweating, yawning; Restlessness, anxiety, insomnia; Muscle aches	Moderate	—
Fully developed withdrawal	1 to 3 days after last use	Dilated pupils, goosebumps; Stomach cramps, nausea, vomiting, diarrhea; Muscle twitching, joint and muscle pain; Fast heart rate, higher blood pressure	Severe	Vomiting or diarrhea you can’t keep up with, or signs of dehydration (dizziness, very little urine); Thoughts of suicide or self-harm: call or text 988 now
Easing	Day 4 to day 10 (total acute withdrawal often 7 to 10 days)	Physical symptoms gradually fade; Tiredness, poor sleep	Moderate	Signs of overdose (slow or stopped breathing, can’t wake up, blue lips): call 911 and use naloxone if you have it
Protracted phase	Weeks to months	Low mood (dysphoria); Cravings; Insomnia; Increased sensitivity to pain	Moderate	Signs of overdose (slow or stopped breathing, can’t wake up, blue lips): call 911 and use naloxone if you have it; Thoughts of suicide or self-harm: call or text 988 now

Print a daily symptom log for this timeline · My quit tracker

Early withdrawal

8 h – 1 day

Fully developed withdrawal

1 day – 3 days

Easing

3 days – 10 days

1 h6 h1 day3 days1 week

MildModerateSevereCan be life-threatening

Symptoms, phase by phase

SAMHSA’s TIP 63 describes opioid withdrawal in stages. Early signs are watery eyes, runny nose, sweating, yawning, restlessness and insomnia, followed by dilated pupils, goosebumps, muscle twitching and aches. Fully developed withdrawal adds fast heart rate, high blood pressure, fever, nausea, vomiting, diarrhea and extreme restlessness. TIP 63 says it feels like gastroenteritis, severe flu, anxiety and dysphoria all at once. MedlinePlus calls the symptoms very uncomfortable but usually not life-threatening on their own. Complications such as dehydration and breathing vomit into the lungs can be serious, and the biggest risk is overdose after withdrawal, because tolerance drops. NIDA notes fentanyl dependence can cause ‘extremely unpleasant withdrawal symptoms’ when someone stops. We use the general short-acting opioid timeline here and say so honestly: we haven’t found a primary source with a fentanyl-specific timeline we’d trust. Illicit fentanyl may also be mixed with other drugs (NIDA notes meth is sometimes combined with fentanyl), which can change what withdrawal looks like.

Early withdrawal: 8 to 24 hours after last use

• Watery eyes, runny nose
• Sweating, yawning
• Restlessness, anxiety, insomnia
• Muscle aches

Fully developed withdrawal: 1 to 3 days after last use

• Dilated pupils, goosebumps
• Stomach cramps, nausea, vomiting, diarrhea
• Muscle twitching, joint and muscle pain
• Fast heart rate, higher blood pressure

Easing: Day 4 to day 10 (total acute withdrawal often 7 to 10 days)

• Physical symptoms gradually fade
• Tiredness, poor sleep

Protracted phase: Weeks to months

• Low mood (dysphoria)
• Cravings
• Insomnia
• Increased sensitivity to pain

What makes withdrawal longer or shorter

• How often and how much. SAMHSA’s TIP 63 says the severity of withdrawal reflects how physically dependent you are.
• Mixed supply. Street fentanyl may include other substances, so withdrawal can be unpredictable.
• Other drugs. SAMHSA’s TIP 63 lists using opioids with alcohol or benzodiazepines as an overdose risk, and NIDA says fentanyl is often mixed with cocaine or methamphetamine.
• Treatment. Buprenorphine and methadone reduce withdrawal; starting buprenorphine needs medical guidance to avoid precipitated withdrawal.

When to see a doctor or get help now

• Before you stop: medicines (buprenorphine, methadone, and the non-opioid lofexidine for withdrawal symptoms) make withdrawal safer and more bearable.
• Get urgent care for vomiting or diarrhea you can’t keep up with, or signs of dehydration.
• Call 911 for any overdose signs. If you return to use after withdrawal, even a smaller amount than before can be fatal.
• Call or text 988 for thoughts of suicide.

Not sure where to start? Call SAMHSA’s free, confidential helpline at 1-800-662-4357, 24/7. See Get Help.

Tapering

Don’t plan a solo fentanyl detox. NIDA says methadone, buprenorphine and naltrexone are FDA-approved to treat opioid use disorder, and lofexidine is approved for withdrawal symptoms. A clinician can tell you how and when to start them safely. Call SAMHSA at 1-800-662-4357 or visit FindTreatment.gov.

Tips for getting through it

• Get medical help and ask about buprenorphine or methadone
• Keep naloxone (Narcan) on hand and tell someone where it is
• Drink enough fluids and eat several small meals, as NSW Health’s opioid withdrawal guidance advises; skip alcohol and go easy on caffeine
• Never use alone, and know that tolerance drops fast after withdrawal
• Find treatment at FindTreatment.gov or call SAMHSA at 1-800-662-4357

Frequently asked questions

How long does fentanyl withdrawal last?

Using the short-acting opioid pattern, acute withdrawal lasts about 7 to 10 days, with low mood, cravings and poor sleep sometimes lasting weeks to months. Fentanyl-specific research is limited.

Is fentanyl withdrawal worse than heroin withdrawal?

We haven’t found strong primary research comparing them directly, so we won’t guess. Both follow the general short-acting opioid pattern.

Why is relapse after fentanyl withdrawal so dangerous?

Withdrawal lowers tolerance. MedlinePlus notes most opioid overdose deaths occur in people who have just detoxed. Fentanyl is extremely potent, so a ‘normal’ dose can be fatal.

Can I start Suboxone on my own?

Ask a clinician. Starting buprenorphine too soon after full opioids like fentanyl can cause precipitated withdrawal, a sudden severe withdrawal.

Next steps

• Track your dayEnter when you stopped to see where you are on the timeline
• Combine timelinesAdd other things you are stopping and see them on one chart
• Talk to othersAsk questions on our community forum (peer support, not medical advice)
• Read nextOpioid Withdrawal Timeline: Short-Acting vs Long-Acting
• Get helpFree, confidential helplines and when to see a doctor

Related timelines

• Opioid Withdrawal Timeline: Short-Acting vs Long-Acting
• Suboxone Withdrawal Timeline
• Methadone Withdrawal Timeline

Sources

1. National Institute on Drug Abuse: Fentanyl
2. SAMHSA: TIP 63, Medications for Opioid Use Disorder (updated 2021), Exhibit 2.10
3. MedlinePlus (U.S. National Library of Medicine): Opiate and opioid withdrawal
4. FDA-approved label: SUBOXONE (buprenorphine and naloxone) sublingual film, via DailyMed
5. SAMHSA National Helpline
6. NSW Health: NSW Clinical Guidelines: Treatment of Opioid Dependence, abbreviated version (2018)

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Last reviewed: October 25, 2026. Researched and written by Withdrawal Timelines from the cited sources. This article has not yet been reviewed by a medical professional. See How We Review and our Medical Disclaimer. This is general information, not medical advice.