How Long Does Alcohol Stay in Your System?
Quick Answer
Alcohol is metabolized at about 1 standard drink per hour. It's detectable in blood for up to 12 hours, urine for 12–80 hours (EtG test), breath for 12–24 hours, and hair for up to 90 days.
Typical Duration
Quick Answer
Your body metabolizes alcohol at a fairly constant rate of about one standard drink per hour. However, alcohol and its metabolites can be detected much longer depending on the test. Blood and breath tests detect alcohol for 12–24 hours, urine tests for 12–80 hours, and hair tests for up to 90 days.
Detection Windows by Test Type
Blood Test
- Detection window: up to 12 hours
- Most accurate for current impairment
- BAC drops by about 0.015% per hour
Breath Test (Breathalyzer)
- Detection window: 12–24 hours
- Measures alcohol in exhaled air from the lungs
- Standard in roadside sobriety testing
Urine Test
- Standard test: 12–24 hours
- EtG (ethyl glucuronide) test: 48–80 hours
- EtG detects a metabolite, not alcohol itself, making it far more sensitive
Saliva Test
- Detection window: 12–24 hours
- Less common than blood or breath tests
Hair Follicle Test
- Detection window: up to 90 days
- Can show patterns of heavy drinking over time
- Not useful for detecting a single episode
How Your Body Processes Alcohol
When you drink, about 20% of alcohol is absorbed through the stomach and 80% through the small intestine. It enters the bloodstream within minutes. The liver does 90–95% of the work metabolizing alcohol using the enzyme alcohol dehydrogenase (ADH), converting it first to acetaldehyde (toxic), then to acetate (harmless), then to water and CO₂.
The liver processes approximately:
- One standard drink per hour (12 oz beer, 5 oz wine, 1.5 oz spirits)
- This rate is relatively fixed — you can't speed it up
BAC Elimination Timeline
| Drinks Consumed | Approximate Time to 0.00% BAC |
|---|---|
| 1 drink | ~1 hour |
| 2 drinks | ~2 hours |
| 3 drinks | ~3–4 hours |
| 5 drinks | ~5–6 hours |
| 8 drinks | ~8–10 hours |
| 10+ drinks | 10–15+ hours |
Times assume a 160 lb person and standard drink sizes.
Factors That Affect Processing Time
Body weight and composition — larger people generally have more blood volume, diluting alcohol. People with more muscle and less fat metabolize alcohol faster.
Biological sex — women typically have less alcohol dehydrogenase and more body fat, leading to higher BAC from the same amount of alcohol.
Food intake — drinking on a full stomach slows absorption significantly. Food doesn't prevent absorption, but it delays the peak BAC.
Liver health — liver damage from chronic drinking or disease slows metabolism.
Age — metabolism slows with age, and older adults typically have less body water.
Medications — many medications interact with alcohol and can slow its metabolism.
What Doesn't Help
- Coffee — doesn't sober you up, just makes you an alert drunk
- Cold showers — no effect on metabolism
- Exercise — minimal effect; only about 5–10% of alcohol leaves through sweat, breath, and urine
- "Hangover cures" — none speed up actual alcohol elimination
When to Seek Medical Help
Seek emergency help if someone shows signs of alcohol poisoning:
- Confusion or stupor
- Vomiting while unconscious
- Slow or irregular breathing (fewer than 8 breaths/minute)
- Blue-tinged or pale skin
- Hypothermia
- Seizures