How Long Does Alcohol Stay in Your System? Blood, Breath, Urine and Hair

Most adults clear about one standard drink every one to two hours, so alcohol usually disappears from blood and breath within a day, but urine EtG tests can detect drinking for up to about 80 hours and hair tests for months.^{1, 2, 11} Exactly how long alcohol stays in your system depends on how much you drank, your size, sex and genes, and whether you ate. No chart or app can tell you when you're safe to drive.

How fast does your body clear alcohol?

Slower than most people think: about 7 grams of alcohol an hour for an average 70-kg adult.¹ A US standard drink contains 14 grams, so for many adults each drink takes one to two hours, not the one hour of the old rule of thumb.^{4, 5} And your drink may be more than one: a 12-oz craft beer at 10% counts as two.⁴ See what counts as a standard drink.

In blood-alcohol terms, BAC typically drops 10–15 mg/100 mL an hour on an empty stomach and 15–20 after food; 15 (a fall of 0.015 percentage points an hour) is a good average for moderate drinkers.⁵ BAC can also keep rising for a while after your last drink, as alcohol still in your gut is absorbed.⁹ For the enzyme-by-enzyme version, see how the body processes alcohol.

How long does alcohol stay in your system? Detection windows by test

Alcohol itself is measurable in blood and urine for only hours, but tests for its byproducts look back days, weeks or months.¹⁰

Breath and blood go negative once BAC is back to zero, which can take most of a day after a heavy night: at an average pace, a peak of 0.15% takes about 10 hours to clear.⁵

Urine EtG is the test people most often ask about. In a controlled study, 10 healthy men drank 0.5 g of alcohol per kg of body weight (about 2.5 US standard drinks for a 70-kg man) on an empty stomach, and EtG and ethyl sulfate (EtS) stayed detectable about 25 hours longer than alcohol itself.⁶ The test is so sensitive that results should be confirmed and read alongside a person's history.²

Hair tests assess patterns, not single nights. The Society of Hair Testing's 2026 consensus says an EtG level of 5 pg/mg or less in hair near the scalp doesn't contradict self-reported abstinence, while 30 pg/mg or more strongly suggests chronic excessive drinking.¹¹

What affects how long alcohol stays in you?

How much you drank matters most, and clearance rates vary three- to fourfold between people.¹

• Amount and pace. More drinks mean more hours. Your clearance rate barely changes, so drinking faster mainly pushes your peak higher.¹
• Body size and sex. Pound for pound, women have less body water than men, so a woman's BAC tends to run higher than a man's of the same weight after the same amount.¹²
• Food. Eating before or with drinks slows absorption, and blood alcohol tends to fall a little faster after a meal.^{1, 5}
• Drinking history. Heavy drinkers often clear alcohol faster because a backup liver enzyme ramps up.⁵ That's adaptation to heavy drinking, not a perk.
• Age. With less muscle and body water, some older adults reach a higher blood alcohol level than younger people after the same amount, and they're more sensitive to alcohol's effects on balance, attention and driving.¹³

How long after drinking can you drive? (Don't guess)

There's no formula that tells you when you're safe to drive. If you've been drinking, plan a designated driver, a rideshare or transit, or stay over.

The legal limit is a BAC of 0.08% in every state except Utah (0.05%), but NHTSA notes that "even a small amount of alcohol can affect driving ability." In 2024, 2,028 people were killed in alcohol-related crashes in which a driver's BAC was 0.01 to 0.07.⁸

The rates come from a review of elimination studies; the arithmetic is ours.⁵ Go to bed at 0.15% at 2 a.m. and, at a slow rate, you'd still have alcohol in your blood at lunchtime. Your BAC may also still be rising when you stop drinking,⁹ and hangovers impair attention and coordination even once BAC is back to zero.¹⁴

Myths about sobering up faster

Nothing you can buy, drink or do makes your liver clear alcohol meaningfully faster. Only time works.¹⁴

• Coffee won't clear alcohol from your system any faster.³
• Cold showers and walking don't reverse alcohol's effects, and can make an overdose worse.⁹
• Water helps thirst, but in a small 2026 randomized trial, water alongside sake didn't change breath alcohol.¹⁵
• Saunas and sweating: less than 10% of alcohol leaves through breath, sweat and urine combined.¹
• Sleep doesn't speed your liver up; it works at the same limited pace.¹
• Supplements: none has been shown in people to bring blood alcohol down faster or make it safe to drive.

More in hangover myths.

Is a hangover the same as alcohol still in your system?

No, but they overlap. Hangover symptoms peak as blood alcohol returns to about zero and can last 24 hours or longer.¹⁴ The morning after a late night, you may have both: leftover alcohol and a hangover arriving as it clears. Neither is compatible with driving. See how long a hangover lasts.

What we don't know yet

• Your own clearance rate. Averages hide a three- to fourfold range, and there's no simple way to measure your personal rate.¹
• Exact test windows. These are typical outer limits, not guarantees, and hair-test cut-offs were revised as recently as 2026.¹¹

The simplest way to keep alcohol from lingering is to drink less of it. The 2025–2030 Dietary Guidelines say: "Consume less alcohol for better overall health."¹⁶ Our guide to drinking responsibly covers pacing and limits.

Published by Fuller Health, which makes After Party. This article is general information, not medical advice: talk to a doctor or pharmacist about your own health, medicines and drinking. Last reviewed October 9, 2026. How we research and write.