How Long Does Alcohol Stay in The Body?

How long can alcohol stay in the body? Does alcohol stay for days? For a few hours? How long after drinking can I drive and still pass a breathalyzer test? Does it matter if I drink beer instead of whiskey? These are important questions. Fortunately, the answers are simple.

Overview

  1. Metabolism
  2. Biphasic Curve
  3. Time is Important
  4. Our Own Alcohol
  5. References

Alcohol leaves the body in two ways. A total of about ten percent leaves through the breath, perspiration, and urine. The process of metabolism breaks down the rest.

I. Metabolism

The rate of metabolized is the same for virtually everyone. No matter their height, weight, sex, race or other such things.

The body metabolizes alcohol at the rate of .015 of blood alcohol concentration (BAC) every hour.1 Thus a person with a BAC of .15 will have no measurable alcohol in the blood after ten hours. That’s because .15 divided by .015 = 10. Here are some other examples:

BAC Level Metabolism Time in Hours
.10 6.66
.08 5.33
.05 3.33
.02 1.33

It’s important to remember that BAC can continue to rise for a period of time after the last drink. That effects how long alcohol stays in our body.

II. Biphasic Curve

Learn about the little-known but very important biphasic curve. It can help us get the most pleasure from alcohol. And help us avoid any of the problems like hangovers. Visit How Alcohol Affects Us: the Biphasic Curve.

We can easily control the rate at which our BAC rises and how high it goes. Here are some tips.

alcohol stay
Standard Drinks
  • Standard drinks of beer, wine, spirits have the same amount of pure alcohol. They’re no different to a breathalyzer. 
  • Eat food as you drink. This slows the absorption of alcohol into your blood.
  • Sip your drinks.
  • Don’t engage in drinking games.
  • Accept a drink only when you’ve decided it’s time for another.
  • Alternate between alcoholic and non-alcoholic drinks.
  • Space out your drinks. A good general guideline for most people is no more than one alcoholic drink per hour.
  • Stay active. This helps you be more aware of any effects alcohol may be having on you.
  • Beware of punches. Stick with standard drink sizes. This makes it easier to control your alcohol intake.
  • Follow any medical advice you receive about drinking when taking medications.2

III. Time is Important

Estimate Your BAC

Try it! Estimate the BAC you would reach when drinking over a variety of time periods. From How to Control Your Drinking by W. Miller and R. Munoz.

Although we can control how high our BAC goes, we can’t speed up our metabolism. Drinking coffee, exercising or taking showers and similar behaviors have no effect on alcohol metabolism. Only time can do that.

To avoid hangovers keep BAC low, no higher than about .05 to .06. There is no evidence that any of the hangover remedies on the market are of any value.

However, clear distilled spirits such as gin and vodka are less likely to cause hangovers.3 Of course, it’s always best to avoid drinking too much alcohol.

IV. Our Own Alcohol

The human body produces alcohol throughout life 24/7. The foods eaten influence to some degree how much alcohol forms. On average, people can produce up to about one ounce of pure alcohol each day.4 However, the law doesn’t distinguish between alcohol naturally in the body and that from drinking.

Unfortunately, so-called alcohol breath testing machines only estimate BAC. Actual BAC measurement requires testing the blood itself. Tests of breath, perspiration and urine can only estimate the amount of alcohol in the bloodstream.

Many people tested with a breathalyzer will receive a reading higher than their actual BAC. This means that many innocent drivers suffer false conviction of DWI/DUI.

But there is good news. You can easily avoid both alcohol-impaired driving and unfair DWI/DUI convictions. Simply don’t drink, drink in moderation, or either serve as or use a designated driver (DD).

V. References for How Long does Alcohol Stay in the Body

  1. Watson, R., et al. Alcohol, Nutrition, and Health. NY: Humana, 2013.
  2. Drinking and Driving.
  3. Prat, G., et al. Alcohol hangover. Hum Psychopharm, 2009, 24, 259–267.
  4. Simic, M., et al. Endogenous ethanol production. Foren Sci Int, 2012, 216(1-3), 97-100. Lindiger, W., et al. Endogenous production of methanol. Alc Clin Exper Res, 1997, 21, 939-943. Phillips, M., et al. Endogenous ethanol. Alcohol, 1986, 3, 239-247. Jones et al., Determination of endogenous ethanol in blood and breath. Pharm Biochem Behav, 1983, 18, 267.