Detox timelines vary significantly depending on the substance, but most acute withdrawal phases last between a few days and a few weeks. Alcohol withdrawal can become dangerous within 48 hours, opioid withdrawal typically peaks within the first few days, and benzodiazepine withdrawal can stretch for months. Beyond the acute phase, lingering psychological symptoms can persist for much longer. Here’s what to expect for the most common substances.
Alcohol: 3 to 7 Days for Acute Withdrawal
Alcohol detox follows a fairly predictable pattern. Mild symptoms like headache, anxiety, and insomnia appear 6 to 12 hours after your last drink. These early symptoms can feel manageable, but the risk escalates quickly. Seizure risk is highest 24 to 48 hours after the last drink in people with severe withdrawal. Delirium tremens, the most dangerous form of alcohol withdrawal involving confusion, rapid heartbeat, and hallucinations, can appear 48 to 72 hours after the last drink.
For most people, the worst physical symptoms resolve within 5 to 7 days. However, the severity depends heavily on how much and how long you’ve been drinking. Someone who drank heavily for years faces a very different withdrawal than someone who binged for a few months. Alcohol is one of the few substances where withdrawal itself can be life-threatening, which is why medical supervision matters more here than with most other drugs.
Opioids: 4 to 10 Days for Most People
Opioid withdrawal is intensely uncomfortable but rarely life-threatening on its own. The timeline depends on which opioid you were using. Symptoms from short-acting opioids like heroin typically start within 12 hours of the last dose, while longer-acting opioids like methadone can take up to 30 hours before withdrawal begins.
The acute phase, which includes muscle aches, nausea, sweating, insomnia, and diarrhea, generally peaks around days 2 to 3 for short-acting opioids and lasts roughly 4 to 7 days. For longer-acting opioids, symptoms peak later and can drag on for 10 days or more. Fentanyl complicates things further because it accumulates in body fat, meaning withdrawal can be unpredictable in both onset and duration depending on how long and how heavily someone used it.
Benzodiazepines: Weeks to Months
Benzodiazepine detox is often the longest and most complex. The timeline hinges on whether you were taking a short-acting or long-acting formulation. Short-acting benzodiazepines can trigger withdrawal symptoms within a few days of stopping, while long-acting versions may not produce symptoms for a full week.
What makes benzo withdrawal especially challenging is its duration. Symptoms from abrupt withdrawal can last weeks to months and commonly include rebound anxiety, insomnia, irritability, and in severe cases, seizures. This is why most medical protocols involve a slow, gradual taper rather than stopping cold turkey. A supervised taper can stretch over several weeks or even months, but it dramatically reduces the intensity and danger of withdrawal.
Stimulants: A Different Kind of Withdrawal
Cocaine and methamphetamine withdrawal looks different from alcohol or opioid withdrawal because the symptoms are primarily psychological rather than physical. The first phase is the “crash,” which hits within hours of your last dose. With methamphetamine, this crash phase involves extreme fatigue, and you may sleep for most of the day for 2 to 4 days straight.
After the crash comes a longer stretch of emotional symptoms: depression, anxiety, paranoia, low motivation, low energy, and intense cravings. These can last for weeks or months. The absence of dramatic physical symptoms sometimes leads people to underestimate stimulant withdrawal, but the psychological toll is significant and is a major driver of relapse.
Marijuana: 1 to 3 Weeks
Cannabis withdrawal is real, though it’s milder than most other substances. Symptoms typically begin within 24 to 48 hours of stopping heavy, long-term use. The severity peaks around day 3, with irritability, sleep disruption, decreased appetite, and cravings being the most common complaints. Most symptoms resolve within 1 to 3 weeks, though sleep disturbances can linger a bit longer. THC is fat-soluble, so chronic heavy users may test positive on drug screens for weeks after quitting even though withdrawal symptoms have already passed.
What Happens in Your Body During Detox
Your liver does the heavy lifting when it comes to clearing substances from your body. It works in two phases. First, a family of enzymes breaks down toxins into less harmful compounds. Then a second set of processes makes those byproducts water-soluble so your kidneys can flush them out. This is why hydration matters during detox, and why people with liver damage from heavy drinking or drug use may experience slower, more complicated withdrawal.
But clearing the substance from your blood is only part of the story. Withdrawal symptoms happen because your brain adapted to the constant presence of a substance by adjusting its own chemistry. When the substance disappears, those adaptations are suddenly working against you. Your nervous system is either overexcited (as with alcohol and benzos) or underperforming its reward and motivation systems (as with opioids and stimulants). The acute withdrawal phase is your brain recalibrating, and how long that takes depends on how deeply those adaptations ran.
Post-Acute Withdrawal Can Last Much Longer
Even after the acute phase resolves, many people experience a second, slower wave of symptoms known as post-acute withdrawal syndrome. This involves psychological and mood-related symptoms: anxiety, irritability, difficulty concentrating, sleep problems, and emotional flatness. These symptoms have been reported after withdrawal from alcohol, benzodiazepines, opioids, marijuana, stimulants, and even caffeine and nicotine.
Post-acute symptoms can last months to years, though they typically fluctuate rather than remaining constant. You might feel fine for a few weeks, then have a rough stretch of low mood or poor sleep before it lifts again. The fluctuating nature catches people off guard because they expect a straight line of improvement. Knowing this pattern is normal can make a real difference in staying on track, since many relapses happen when someone interprets these waves as a sign that recovery isn’t working.
Factors That Affect Your Timeline
No two detox experiences are identical. Several factors push your personal timeline shorter or longer:
- Duration of use. Someone who used a substance daily for years will generally have a longer, more intense withdrawal than someone who used for a few months.
- Dosage. Higher doses create deeper physiological adaptations, which take longer to reverse.
- Polysubstance use. Using multiple substances simultaneously complicates withdrawal because your body is adjusting to the absence of more than one drug at a time.
- Overall health. Liver function, kidney function, age, nutrition, and hydration all influence how efficiently your body clears substances and how well it tolerates the stress of withdrawal.
- Previous withdrawal episodes. With alcohol in particular, each withdrawal episode tends to be more severe than the last, a phenomenon sometimes called “kindling.”
The acute physical detox is the shortest part of recovery. For most substances, the hardest days are behind you within one to two weeks. But the psychological adjustment, relearning how to sleep, manage stress, and experience pleasure without the substance, is a longer process that extends well beyond the detox window.