How Long Does Drug Detox Take? Timelines by Substance

Drug detox duration varies significantly by substance, history of use, and individual physiology. There is no single answer — a person detoxing from fentanyl after years of daily use will have a very different experience than someone completing a short course of benzodiazepines. At Hope Harbor Addiction Center in Cherry Hill, NJ, medical detox is individualized from day one. Here is what the science says about withdrawal timelines for the substances we most commonly treat.

Opioid and Heroin Detox Timeline

Opioid withdrawal is driven by the half-life of the substance involved. Short-acting opioids — heroin, oxycodone, hydrocodone — clear the body quickly, producing rapid-onset and intense withdrawal. Long-acting opioids — methadone, extended-release morphine — have a slower curve.

• Short-acting opioids: Symptoms typically begin 8–24 hours after the last use, peak between 36 and 72 hours, and subside over 5–7 days. Peak symptoms include severe muscle aches, sweating, chills, insomnia, nausea, vomiting, diarrhea, and intense drug cravings.
• Long-acting opioids/methadone: Symptoms may not begin until 36–48 hours after the last dose, peak around day 3–4, and can extend for up to three weeks due to the drug's extended half-life and tissue accumulation.

Post-acute withdrawal syndrome (PAWS) — including persistent insomnia, anxiety, low mood, and cravings — can follow acute opioid detox and last weeks to months. Medically supervised detox combined with medication-assisted treatment (MAT) using buprenorphine or naltrexone significantly reduces this burden.

Fentanyl Detox Timeline

Fentanyl presents a more complex detox picture than traditional heroin. Despite being a short-acting opioid pharmacologically, fentanyl is highly lipophilic — it binds to and accumulates in fatty tissue. This means the effective half-life for heavy users can be significantly longer than heroin, and withdrawal symptoms may not peak until 48–96 hours after the last use. The overall detox duration tends to be more protracted, and post-acute symptoms can be more intense.

An additional complication in today's drug supply: xylazine co-contamination. A large portion of street fentanyl in South Jersey and the greater Philadelphia region is now adulterated with xylazine (tranq), a veterinary sedative. Xylazine produces its own withdrawal syndrome — characterized by intense agitation, sweating, and dysphoria — that does not respond to standard opioid withdrawal protocols. Clinicians must be prepared to address both simultaneously. Learn more about fentanyl addiction treatment in Cherry Hill.

Benzodiazepine Detox Timeline

Benzodiazepine withdrawal is, after alcohol, the most medically dangerous withdrawal a patient can experience. Seizures are a real risk, and abrupt discontinuation of long-term benzo use without medical management is life-threatening. This is not a detox to attempt at home.

• Short-acting benzodiazepines (Xanax/alprazolam, Ativan/lorazepam): Withdrawal symptoms can begin within 24 hours of the last dose, with a rapid and intense onset.
• Long-acting benzodiazepines (Valium/diazepam, Klonopin/clonazepam): Symptoms may be delayed 1–2 days due to active metabolites, but can be prolonged and severe.

Medical management typically involves a slow taper — often converting to a long-acting benzo and gradually reducing the dose over 2–4 weeks, sometimes longer for patients with extended use histories. The seizure risk remains present throughout the taper, which is why this process requires clinical oversight. See our dedicated benzodiazepine detox page for more detail.

Alcohol Detox Timeline

Like benzos, alcohol withdrawal can be fatal without medical supervision. The timeline runs from early symptoms at 6–12 hours after the last drink, through peak seizure risk at 24–48 hours, with delirium tremens possible between 48–72 hours for patients with severe dependence. Most patients stabilize within 5–7 days with appropriate medical management. For a complete breakdown, see how long does alcohol detox take.

Meth and Stimulant Detox

Stimulant withdrawal differs fundamentally from depressant withdrawal. Methamphetamine and cocaine do not carry the seizure risk associated with alcohol and benzodiazepines. Instead, withdrawal is characterized by a prolonged "crash" and recovery phase:

• Crash phase (Days 1–3): Extreme fatigue, hypersomnia, and intense depression following cessation. The brain's dopamine system — depleted by stimulant use — produces a profound absence of pleasure or motivation.
• Post-acute phase (Weeks 2–4): Dysphoria, anhedonia (inability to feel pleasure), sleep disruption, cognitive fog, and intense cravings. This is the phase with the highest relapse and psychiatric risk.

While stimulant withdrawal is not medically dangerous in the same way as alcohol, the psychiatric risks — including suicidal ideation during the crash phase — require monitoring. Learn more about meth addiction treatment in Cherry Hill.

Cocaine Detox

Cocaine withdrawal follows a similar pattern to methamphetamine — crash, dysphoria, and protracted cravings — but typically moves through the acute phase faster due to cocaine's shorter half-life. The crash phase lasts 1–3 days, followed by 1–4 weeks of depressive symptoms, low energy, and intense cravings, particularly in environments or situations associated with previous cocaine use. Psychiatric monitoring during the post-acute phase is important, especially for patients with co-occurring depression or anxiety.