Opioid Withdrawal Symptoms Hour by Hour
- January 13, 2023
- , Opioids, Withdrawal
Opioid withdrawal symptoms often start within hours of the last dose. Many people notice early signs within about 12 hours. The hardest physical stretch is often the first few days, commonly the first 72 hours. For many people the worst of that wave eases within about five to seven days. Mood, sleep, and cravings can last weeks. Timing varies by the opioid, how long it was used, the dose, your health, and whether buprenorphine (Suboxone) is started. The tables below are educational ranges, not a personal medical timeline. If you feel unsafe, get emergency care.
Updated September 17, 2026. This page is educational. It is not a diagnosis, a detox plan, or a cue to start or stop medication on your own. Hour labels are ranges restated from Recovery Delivered’s existing pages. They are not 72 one-hour clocks.
Hour-by-hour opioid withdrawal timeline
People searching for opioid withdrawal symptoms hour by hour are usually trying to tell whether what they feel is expected. Short-acting opioids, including heroin and many pain pills, often start within a few hours. Fentanyl withdrawal commonly shows an early cluster around 12 to 30 hours. Longer-acting medicines can take longer to show. None of these windows is a clock you can set.
| Hours after last dose | What many people notice |
|---|---|
| 0 to 6 hours | Some people feel little yet. Others notice early anxiety, restlessness, or yawning after short-acting opioids. Low mood can show up after only a few hours. This is not a clock that says you should already be sick. |
| 6 to 12 hours | Many people notice early signs within about 12 hours: runny nose, watery eyes, sweating, muscle aches, and more restlessness. Short-acting opioids are more likely to show here. Some people still feel little. |
| 12 to 24 hours | Stomach cramps, nausea, goosebumps, chills, dilated pupils, and trouble sleeping are common. Cravings often get stronger. For fentanyl, this window overlaps the early 12 to 30 hour cluster. |
| 24 to 48 hours | Physical symptoms are often climbing. Vomiting, diarrhea, body aches, a faster heart rate, and higher blood pressure can show up. Dehydration risk is higher. This is part of the first-72-hour stretch, not a separate disease. |
| 48 to 72 hours | Physical symptoms are often at their hardest. Rest is difficult. Hour 72 is commonly described as the peak window, not a promise that it ends here. |
| 72 hours to 5 days | For many people the worst physical wave starts to ease. Sleep, mood, energy, and cravings can still be rough. After fentanyl, this can still be an acute stretch (about 3 to 5 days on that timeline page). |
| 5 to 7 days | For many people the worst of that wave eases within about five to seven days, the same heavy-symptom window named on the Lucemyra page. Acute symptoms can last longer, including into a second week, especially after fentanyl. |
| After 7 days | Physical symptoms often lessen. Anxiety, depression, insomnia, low energy, and cravings can continue for weeks. Some people have a longer tail. That longer stretch is still a reason to stay in care, not a reason to wait it out alone. |
The same hour labels shift by opioid. This second table restates windows already on this site. It is not a third clock.
| Window | Short-acting (heroin, many pills) | Fentanyl | Longer-acting medicines |
|---|---|---|---|
| Early cluster | Often within hours; many people by about 12 hours | Commonly 12 to 30 hours | Can take longer to show |
| Hardest physical stretch | Commonly the first 72 hours | Acute stretch often days 3 to 5; can last up to 2 weeks | Varies; can start later |
| When the worst wave often eases | Often 5 to 7 days | Can extend into a second week | Varies |
What you feel also depends on dose, how long you used, other substances, and your health. Research on prescription opioids notes that even a short course can raise the chance of longer use. That does not tell you your hour-by-hour path. A clinician should.
Common opioid withdrawal symptoms
Opioid withdrawal can feel like a severe flu plus panic and craving. Common symptoms include:
- Anxiety, irritability, and depression
- Strong cravings
- Muscle and body aches
- Sweating, chills, and goosebumps
- Nausea, vomiting, diarrhea, and stomach cramps
- Rapid breathing and a faster heart rate
- Higher blood pressure
- Trouble sleeping
- Runny nose, watery eyes, and yawning
- Dilated pupils
Seizures and hallucinations are not typical of uncomplicated opioid withdrawal. If either happens, treat it as an emergency. It may be another medical problem, another substance, or severe complications. Get care now rather than waiting for a table to catch up.
When withdrawal is dangerous
Opioid withdrawal is often described as miserable rather than immediately life-threatening. Unmonitored withdrawal can still turn dangerous. Seek emergency care if you or someone with you has:
- Vomiting or diarrhea so heavy that fluids will not stay down
- Confusion, fainting, severe dizziness, or muscle weakness
- Chest pain, a very fast or irregular heartbeat, or trouble breathing
- A known heart condition plus a rising pulse or blood pressure
- A seizure, severe agitation, or a sudden change in awareness
- Thoughts of harming yourself, or you do not feel safe
Loss of fluids from fever, diarrhea, and vomiting can lead to severe dehydration and unsafe electrolyte shifts. People with heart disease are at extra risk when blood pressure and pulse climb. The other high-risk moment is returning to use after a pause. Tolerance drops quickly. The same amount that was tolerated before can cause an overdose.
If you have any reason to believe you or somebody else is in danger from withdrawal or overdose, contact emergency services immediately. Naloxone (Narcan) reverses an opioid overdose and should be used if overdose is suspected, then emergency care still needs to follow.
How buprenorphine (Suboxone) changes the picture
Buprenorphine is a partial opioid agonist. Suboxone combines buprenorphine with naloxone. When a licensed provider starts buprenorphine at the right time, it often eases withdrawal and cravings because it occupies the same receptors in a steadier, partial way. That can make the hour-by-hour table above much less of the story. People in treatment are not supposed to white-knuckle the peak.
It is not a promise of zero symptoms. It is also not a medication to start from a timeline on a webpage. If buprenorphine is taken while a full opioid is still occupying those receptors, it can cause precipitated withdrawal: a sudden, intense worsening. A provider times the first dose. This page is not a start-time calculator and not a dosing guide.
If you later stop buprenorphine, that is a different withdrawal, often slower. See our guide to Suboxone withdrawal symptoms. For timing questions in treatment, talk with your provider rather than using an old wait-hour list from the internet.
Learn more about online Suboxone doctors and what opioids are.
Why withdrawal feels this way
The body has opioid receptors throughout the brain and spinal cord. Prescription and illicit opioids bind those receptors and change how pain, stress, and breathing are regulated. The body also makes its own endorphins. With repeated opioid use, the nervous system adapts. When the opioid stops, those adaptations are unopposed for a while: more anxiety, more pain signaling, restlessness, and flu-like physical symptoms.
That is why willpower is a weak plan for the first days. Medication for opioid use disorder exists so you do not have to wait the peak out unsupported.
Common questions
How soon do opioid withdrawal symptoms start?
Often within hours. Many people notice early symptoms within about 12 hours of the last dose. Short-acting opioids can start sooner. Fentanyl often shows an early window around 12 to 30 hours. Longer-acting medicines can take longer. This is an educational range, not your personal clock.
How long does opioid withdrawal last?
The hardest physical stretch is often the first few days, commonly the first 72 hours. For many people the worst of that wave eases within about five to seven days. Mood, sleep, and cravings can last weeks, and some people have a longer tail. Seek care rather than waiting to see which group you are in.
When is opioid withdrawal dangerous?
Get emergency care for severe dehydration, confusion or fainting, chest pain, trouble breathing, a seizure, or if you do not feel safe. Returning to use after a pause also raises overdose risk because tolerance drops. Unmonitored withdrawal can be dangerous even when the first hours felt “only like the flu.”
Does Suboxone stop opioid withdrawal?
Buprenorphine, the main medicine in Suboxone, often eases withdrawal and cravings when a licensed provider starts it at the right time. It does not mean zero symptoms. Starting it too soon after a full opioid can cause precipitated withdrawal, a sudden worsening. A provider decides timing. This page is not a start-dose or start-time guide.
Is the hour-by-hour table the same for everyone?
No. The opioid, how long it was used, dose, health, other substances, and whether buprenorphine is started all change the picture. Use the table to know what to watch for, then get care. Do not use it to decide you are “not sick enough yet” or “already through it.”
What should I expect in the first 12 hours?
Often early signs: anxiety, restlessness, yawning, runny nose, watery eyes, sweating, or muscle aches. Some people feel little yet. Short-acting opioids can start sooner. Fentanyl often shows later, around 12 to 30 hours. This is an educational range, not your personal clock.
Is hour 72 the end of withdrawal?
No. The first 72 hours are commonly the hardest physical stretch, not a finish line. For many people the worst of that wave eases within about five to seven days. Mood, sleep, and cravings can last weeks. Do not use hour 72 to decide you are already through it.
How is fentanyl different hour by hour?
Fentanyl commonly shows an early cluster around 12 to 30 hours, then an acute stretch around days 3 to 5 that can last up to two weeks. That is why the hour table above is a range, not a fentanyl clock. See the fentanyl withdrawal timeline for that page’s windows.
Get support during withdrawal
You do not have to ride this out hour by hour without a plan. Recovery Delivered connects you with a licensed provider who can talk through whether buprenorphine is appropriate and what to do next.
One next step: book a visit or Contact support. If Suboxone is right for you, your provider can take the next step. If it is not, they should say so.