Take a sip of alcohol and you may start to feel its effects right away. But it could take several hours or even longer for your body to fully break down that booze.
Even after the breakdown is complete, alcohol can still affect how you think and feel. Some of the byproducts your body creates when it processes alcohol can hang around in your system for hours or even days.
What follows will help you better understand what happens to alcohol once you consume it and what it can do to your body.
What Is Alcohol Metabolism?
Alcohol metabolism is the process through which your body breaks down and rids itself of alcohol.
When you swallow alcohol, it soaks into the tissues of your stomach and upper intestine. From there, the alcohol floods your bloodstream.
In healthy people, blood circulates throughout the body in just 90 seconds. It goes to your brain, lungs, and other tissues. That’s why you feel the effect of alcohol almost immediately after drinking -- because it courses through your whole body in minutes. The effects continue to build for 15 to 45 minutes. Longer if you keep drinking.
Most of the alcohol your body absorbs ends up in your liver. There, enzymes break the alcohol down into byproducts. One of the byproducts, acetaldehyde, is highly toxic. It causes or contributes to these effects of drinking:
Normally, your body quickly turns acetaldehyde into acetate, which is harmless. Acetate and other alcohol byproducts quickly move to your kidneys and then to your urine.
But if you drink faster than your liver can break the stuff down, your blood alcohol level (BAC) will keep going up. Also, your liver will struggle to turn toxic acetaldehyde into harmless acetate. This makes you feel drunker.
How Long Do Alcohol’s Effects Last?
That depends on how quickly and efficiently your body breaks down and clears out alcohol.
Those processes depend on a lot of different factors, including:
- How much you weigh
- Your sex
- Your age
- How much you’ve had to drink
- The type of alcohol you’re drinking
- Your liver’s health
It also matters how much you’ve had to eat. Food soaks up alcohol and slows its absorption. This can reduce the effects. It can also change the amount of time alcohol stays in your blood, which can range from 6 to 14 hours, depending on how much you’ve had to drink.
When Is It Safe to Drive After Drinking?
That depends on how much you’ve had to drink. It also depends on some of those other factors, like your weight and how much you’ve had to eat.
A man’s blood alcohol levels will usually return to zero about an hour after he has a single “standard” drink. For women, this process might take a little longer. One standard drink is:
- 12 oz of 5% ABV beer
- 5 oz of 12% ABV wine
- 1.5 oz of 40% ABV liquor
ABV stands for “alcohol by volume.” If you’ve had a big night out with lots of drinking, alcohol may stay in your blood for 14 hours or longer. Also, a bad hangover can impair your ability to drive as much as having a few drinks.
Is It Safe to Drink and Breastfeed?
According to the CDC, women should avoid nursing for 2 to 3 hours for each drink they’ve had. “Pumping and dumping” won’t lower the amount of alcohol in a woman’s breast milk any faster.
U.K. National Health Service (NHS): “How long does alcohol stay in your blood?”
Bowling Green State University: “Alcohol Metabolism.”
Responsible Drinking: “What happens when you drink?”
U.S. National Institute on Alcohol Abuse and Alcoholism (NIAAA): “Alcohol Metabolism: An Update,” “What is a standard drink?”
American Addiction Centers: “How long does alcohol stay in your system?”
Psychopharmacology: “Effects of alcohol hangover on simulated highway driving performance.”
CDC: “Breastfeeding: Alcohol.”