How long a detox takes depends entirely on what you’re detoxing from. Acute alcohol withdrawal peaks within 24 to 72 hours but can linger for weeks. Heroin withdrawal typically lasts about five days. And if you’re thinking about a juice cleanse or commercial detox product, the honest answer is that your body already handles detoxification continuously, and those programs can do more harm than good in as little as three days.
How Your Body Detoxifies Itself
Your liver runs a two-phase detoxification system around the clock. In the first phase, enzymes break down toxic substances into intermediate compounds. In the second phase, liver cells attach molecules like amino acids or sulfur to those intermediates, making them water-soluble enough to be excreted through urine or bile. This isn’t something you need to activate or schedule. It happens continuously as long as your liver is functioning.
The timeline for clearing a specific substance depends on the substance itself, how much of it is in your system, and how healthy your liver and kidneys are. There’s no single number that applies to everyone, which is why “how long should you detox” has a different answer depending on context.
Alcohol Detox: Days to Weeks
For people who drink heavily and stop, withdrawal symptoms typically peak between 24 and 72 hours after the last drink. Most people with mild to moderate withdrawal see symptoms begin to resolve in that same window. But some symptoms, particularly sleep disruption, anxiety, and mood changes, can persist for weeks.
Organ recovery takes longer. A 2021 review of multiple studies found that two to four weeks of abstinence helped heavy drinkers reduce liver inflammation and bring down elevated liver enzyme levels. That’s a meaningful marker, but it doesn’t mean the liver is fully healed in a month. For people with more advanced liver damage, recovery can take months or may not fully reverse.
Alcohol is one of the substances where unsupervised withdrawal can be genuinely dangerous. Severe withdrawal can cause seizures, psychosis, confusion, and disorientation. If you’ve been drinking heavily for an extended period, medical supervision during detox isn’t optional.
Opioid Detox: 5 to 14 Days
The timeline for opioid withdrawal depends on which opioid you’ve been using. Short-acting opioids like heroin produce withdrawal symptoms that start 6 to 12 hours after the last dose and last roughly five days. Longer-acting opioids like methadone or sustained-release formulations take longer to leave the system, so withdrawal starts later but stretches out over a longer period, sometimes up to two weeks or more.
Opioid withdrawal is intensely uncomfortable (muscle pain, nausea, insomnia, restlessness) but rarely life-threatening on its own. The bigger risk is relapse. Detoxing without any follow-up support significantly increases the chance of returning to use, and tolerance drops quickly during abstinence, making a relapse dose far more dangerous than it would have been before.
Substances That Require Medical Supervision
Not all withdrawal is safe to manage at home. Alcohol, benzodiazepines, GHB, and ketamine can all produce withdrawal symptoms that are medically serious. Seizures are the most acute risk, but psychosis and severe confusion are also possible. For these substances, a supervised detox program, typically lasting 5 to 10 days in a clinical setting, is the safest approach.
The length of medically supervised detox varies by facility and individual need. Some programs run three to five days for stabilization, while others extend to 7 to 10 days for patients with complicated histories or polysubstance use. The goal of medical detox is to get you through the acute withdrawal phase safely. It is not treatment in itself, just the first step.
Juice Cleanses and Commercial Detox Programs
Most commercial detox products and juice cleanses promise to “flush toxins” in 3, 7, or 21 days. There’s no clinical evidence that these programs clear toxins any faster than your liver and kidneys already do on their own. No published study has demonstrated that juice fasting improves toxin clearance compared to eating a normal balanced diet.
What the research does show is that juice-only diets can cause measurable harm surprisingly quickly. A study published in Nutrients found that just three days on a vegetable and fruit juice-only diet triggered shifts in gut and oral bacteria linked to inflammation and cognitive decline. The juice-only group showed the most significant increase in bacteria associated with inflammation and increased gut permeability, while a comparison group eating whole plant foods saw more favorable changes. The oral microbiome was hit even harder, with reductions in beneficial bacteria and increases in inflammatory species. The likely culprit is the near-total absence of fiber, which feeds the bacterial populations that keep your gut healthy.
If your goal is to support your body’s natural detox processes, eating whole foods with adequate fiber, staying hydrated, sleeping well, and reducing alcohol intake will do more than any packaged cleanse. These aren’t dramatic interventions, but they’re what the biology actually responds to.
General “Reset” Detoxes: What the Timelines Mean
Many people searching “how long should you detox” aren’t dealing with substance dependence. They want to know how long to cut out sugar, processed food, or alcohol to feel noticeably better. Here’s what the body actually does with those timelines:
- 3 to 5 days: Blood sugar levels stabilize after cutting refined sugar. Cravings typically peak around day two or three and start declining.
- 1 to 2 weeks: Sleep quality and energy levels often improve after eliminating alcohol, even for moderate drinkers.
- 2 to 4 weeks: Liver inflammation markers begin normalizing in heavy drinkers. Digestive function often improves with increased fiber and whole food intake.
- 1 to 3 months: Skin, weight, and cardiovascular markers show more sustained changes from dietary shifts.
The pattern across all of these is that meaningful change starts within the first two weeks, but the benefits compound over months. A three-day cleanse is too short to produce lasting physiological change. A month of consistent, whole-food eating with adequate sleep and moderate exercise does far more than any structured “detox” program, and you can maintain it indefinitely without depleting your gut bacteria in the process.