Detox typically lasts anywhere from a few days to several weeks, depending on the substance involved. Alcohol withdrawal runs its course in about 5 to 7 days for most people, opioid detox takes 4 to 20 days, and benzodiazepine tapers can stretch from weeks to months. These are the acute physical phases. A slower, subtler recovery period often follows and can last much longer.
Alcohol: 5 to 7 Days for Most People
Alcohol withdrawal symptoms typically start about 6 hours after the last drink. Early symptoms like anxiety, tremors, nausea, and sweating can appear within the first 4 to 48 hours. Seizures are the most dangerous early complication, with over 90% occurring within the first 48 hours of stopping.
For people with severe dependence, a condition called delirium tremens can develop 48 to 72 hours after the last drink, bringing confusion, hallucinations, and dangerously elevated heart rate and blood pressure. This stage can last up to 2 weeks in rare cases, though it only affects a small percentage of people going through withdrawal. Hallucinations on their own can persist for up to 6 days.
People with mild withdrawal and low risk of complications can often be monitored for up to 36 hours, after which more severe symptoms are unlikely to develop. In a medical setting, treatment that adjusts medication based on symptoms (rather than a fixed schedule) has been shown to shorten the overall length of stay.
Opioids: 4 to 20 Days
The timeline for opioid detox depends heavily on whether you’re withdrawing from a short-acting or long-acting opioid. With short-acting opioids like heroin or fentanyl, symptoms begin 8 to 24 hours after the last dose and last roughly 4 to 10 days. With long-acting opioids like methadone, onset is slower (12 to 48 hours) but the process drags on longer, typically 10 to 20 days.
Symptoms include muscle aches, nausea, diarrhea, chills, and intense cravings. The experience is often compared to a severe flu. Opioid withdrawal is rarely life-threatening on its own, but it’s intensely uncomfortable, which is a major reason people relapse during this window.
The length of the detox program matters. A study comparing 5-day and 30-day medically assisted opioid detox found striking differences: only about 4% of people in the 5-day program successfully completed detox, compared to nearly 16% in the 30-day program. Those in the longer program were also significantly more likely to transition into ongoing treatment afterward (41% versus 26%). Longer detox gave people more time to stabilize physically and engage with counseling before being on their own.
Benzodiazepines: Weeks to Months
Benzodiazepine detox is fundamentally different from most other substances because stopping abruptly can cause life-threatening seizures. For this reason, detox almost always involves a gradual taper, slowly reducing the dose over time rather than stopping all at once.
A standard taper runs 8 to 12 weeks, with the option to slow down if symptoms become too difficult. Some people need much longer. Tapers lasting one to two years can still be successful for those who need a gentler pace. On the other hand, extending beyond six months sometimes backfires, as the drawn-out process itself can fuel anxiety and make outcomes worse. The right speed is highly individual.
Stimulants: 1 to 3 Weeks
Methamphetamine and cocaine withdrawal follows a different pattern than depressants. There’s less physical danger, but the psychological symptoms hit hard. Withdrawal severity peaks within the first 24 hours and then declines steadily over about a week. This acute phase is marked by excessive sleeping, increased appetite, depression, anxiety, and cravings.
After that initial 7 to 10 days, a subacute phase continues for at least another 2 weeks. Symptoms during this period are milder but persistent, mostly low mood and fatigue. Unlike alcohol or opioid withdrawal, stimulant detox doesn’t typically require medication to manage physical symptoms, but the depression and cravings that follow can be significant relapse triggers.
Cannabis: 1 to 3 Weeks
Cannabis withdrawal is real, though it’s milder than what people experience with alcohol or opioids. Symptoms start 24 to 48 hours after stopping, peak around days 2 through 6, and generally improve over the first week. Heavy, long-term users can experience withdrawal symptoms for 2 to 3 weeks or longer.
The main symptoms are irritability, sleep disruption, decreased appetite, and cravings. One reason cannabis withdrawal lasts as long as it does is that THC is highly fat-soluble. It binds to fat tissue throughout the body, creating a reservoir that slowly releases the compound back into the bloodstream. This is also why THC metabolites show up on urine tests weeks after the last use.
What Makes Detox Longer or Shorter
The timelines above are averages. Several factors push your personal detox closer to the shorter or longer end of the range:
- How long and how much you used. Repeated exposure to a substance causes the body to ramp up production of the enzymes needed to process it. This contributes to tolerance and means the body has more adjusting to do when the substance is removed.
- Age. Drug metabolism slows with age, which means older adults may process substances out of their system more slowly and can be more susceptible to withdrawal complications.
- Body composition. Fat-soluble substances like THC and certain benzodiazepines are stored in fat tissue, which acts as a slow-release depot. People with higher body fat may experience a more drawn-out clearance period.
- Using multiple substances. Polysubstance use complicates withdrawal because the body is adjusting to the absence of more than one drug simultaneously, often extending the overall timeline.
- Previous withdrawal episodes. Each round of withdrawal from alcohol, in particular, tends to be more severe than the last, a phenomenon known as kindling.
Post-Acute Withdrawal: The Longer Recovery
Once the acute physical detox ends, many people enter a phase of lingering symptoms that can last months. The American Society of Addiction Medicine defines this as symptoms of irritability, anxiety, and sleep disturbance that persist beyond 30 days from the start of acute withdrawal.
This post-acute phase is most studied in alcohol recovery, where it involves anxiety, depression, inability to feel pleasure, sleep problems, cognitive fog, cravings, and irritability. These symptoms are most severe in the first 4 to 6 months of abstinence. Cravings tend to peak in the first 3 weeks, while sleep disruption can persist for roughly 6 months. Mood and anxiety symptoms can linger for much longer, in some cases years, though they gradually diminish with sustained abstinence.
Cognitive impairment, things like difficulty concentrating and memory problems, generally clears within a few weeks to a few months, though some residual effects can last up to a year. This phase is often the most underestimated part of recovery. People expect to feel normal once the physical withdrawal ends, and the persistence of these subtler symptoms catches them off guard. Understanding that this is a normal, predictable part of the process makes it easier to manage.