How Long Does Alcohol Stay in Your System?

How your body processes alcohol

According to the National Institute on Alcohol Abuse and Alcoholism (NIAAA), alcohol is absorbed through the stomach and small intestine and then carried through the blood. The liver does most of the work of breaking it down.

Liver enzymes turn alcohol into acetaldehyde, a toxic compound, and then into acetate, which the body breaks down further into water and carbon dioxide. A small share leaves the body unchanged through breath, sweat and urine.

A general timeline

On average, the body clears roughly one standard drink per hour, though this varies widely. Blood alcohol keeps rising for a while after your last drink, because alcohol is still being absorbed.

In the US, a standard drink is about 12 ounces of regular beer, 5 ounces of wine, or 1.5 ounces of distilled spirits. Many poured drinks contain more than one standard drink, which makes the clock run longer than people expect.

What affects how long alcohol stays in your system

• Amount and speed. More drinks, or drinks taken quickly, raise blood alcohol higher and take longer to clear.
• Body size and composition. Body weight and the share of body water change how concentrated alcohol becomes.
• Sex. Women often reach higher blood alcohol levels than men after the same amount, due partly to body water and enzyme differences.
• Food. Eating before or while drinking slows absorption, though it does not speed up clearing.
• Age and liver health. Older age and liver conditions can slow how alcohol is processed.
• Medicines. Some medicines interact with alcohol. A pharmacist or doctor can tell you about yours.

How long alcohol can be detected

Detection times are approximate and depend on the amount consumed and the test used. MedlinePlus describes several common types of alcohol testing.

• Breath and blood. These measure alcohol currently in your body and usually reflect recent drinking over hours.
• Urine. Standard tests reflect recent hours, while tests for byproducts such as ethyl glucuronide (EtG) can show drinking from up to a few days earlier.
• Hair. Some specialized tests look for alcohol byproducts over a much longer period, often months.

Results vary between people and labs, so these windows are general ranges, not exact rules. If you have questions about a test you need to take, ask the provider or organization giving it.

Why the timeline matters for safety

Feeling sober is not the same as being alcohol free. Judgment and reaction time can stay affected even when you feel fine, which is why the National Highway Traffic Safety Administration urges planning a sober ride before you drink. The morning after a heavy night is a common time for people to drive while still impaired.

When the question points to something bigger

Sometimes worrying about how long alcohol lasts is a sign drinking is taking up more space than you want. NIAAA's Rethinking Drinking site offers a private way to look at your patterns.

If you drink daily or heavily, stopping suddenly can bring on withdrawal, which can be dangerous. Talk with a doctor before you stop, and read our alcohol withdrawal timeline guide to understand what to expect. Our guides on how to stop drinking, the benefits of quitting over time and medication for alcohol cravings can help you plan next steps.

You can also read about trying a sober curious approach, learn the signs of a functioning alcoholic, or browse our support resources.

Frequently asked questions