Time clears THC. Nothing else does.
There is no drink, food, shower, or supplement that removes THC from blood in minutes. THC leaves the body at a fixed rate set by liver enzymes. A cold shower changes how you feel. It does not change the drug level. The only reliable way to sober up is to wait.
First Aid for Greening Out at Home: Step-by-Step
How long you wait depends on the route of use, the dose, and your tolerance.
How long impairment lasts
- Smoked or vaped: onset in 1 to 10 minutes. Peak in 15 to 30 minutes. Noticeable impairment for 2 to 4 hours.
- Edibles and drinks: onset in 30 to 120 minutes. Peak at 2 to 4 hours. Impairment for 4 to 6 hours. Residual effects can run 12 hours or longer.
- Concentrates and dabs: higher THC per dose. Effects start fast and last longer than flower for many users.
- Daily heavy users: report shorter highs. Blood THC still sits above the impairment range for hours.
THC plasma half-life is about 30 minutes. The metabolite THC-COOH has a terminal half-life of up to 5 days in blood and longer in chronic users. A urine test can stay positive 30 days after the last use in heavy users. No home remedy changes that window.
How Many Hours Does It Take to Not Be High?
What actually helps
- Wait. Track the clock from your last dose, not from when you felt it.
- Sleep. Most people wake with the high gone or close to gone.
- Water. Hydration eases dry mouth and headache. It does not flush THC.
- Food. A meal with protein and fat settles the stomach and helps if you feel lightheaded.
- Low stimulation. Dim light, quiet room, one task at a time. This lowers anxiety, which is often the worst part of a strong high.
- Stay with someone. A calm person in the room reduces panic and catches problems early.
What does not work
- Coffee and energy drinks. Caffeine raises heart rate and can add jitter to existing anxiety.
- Cold showers. No effect on THC levels. A sudden temperature shift can cause a dizzy spell.
- Hard exercise. THC is stored in fat. Working out does not release enough to matter in the next hour and raises injury risk while impaired.
- Detox drinks and pills. No product is FDA-approved to lower blood THC. Some only dilute urine, which testing labs flag as invalid.
- Black pepper, lemon, pine nuts. Anecdotal claims. No clinical trial shows they cut impairment time.
Edibles need a different plan
Edibles pass through the liver, which converts THC into 11-hydroxy-THC. That form is stronger and lasts longer. Eating more because the first dose feels slow is the most common cause of a bad edible night. If you took too much, plan for 6 hours, not 2. Do not redose. Do not drive.
Do not drive
NHTSA and CDC data show cannabis slows reaction time and impairs lane keeping for 2 to 4 hours after smoking. Edible impairment can run past 6 hours. A person can feel fine and still fail a field sobriety test. In every US state, driving under the influence of cannabis is illegal.
When to get help
Call 911 or Poison Control at 1-800-222-1222 if you see:
- Chest pain, a racing pulse that will not settle, or trouble breathing
- Severe panic, confusion, or thoughts of self-harm
- Repeated vomiting, especially with stomach pain (symptoms of cannabinoid hyperemesis syndrome)
- A child who ate an edible
These events are rare. They are also the cases where the wait it out advice does not apply.
Summary
Peak effects: 15 to 30 minutes after smoking, 2 to 4 hours after an edible. Full clearing: 2 to 4 hours for smoked, 4 to 6 hours or more for edibles. Sleep, water, food, and a calm room help you cope. Nothing shortens the clock.