Absorption Rate

There are at least a dozen factors that influence how fast you absorb alcohol, and your absorption rate can determine whether you are legally guilty of DUI.

Absorption rate refers to how fast your body absorbs alcohol and gets it into the blood stream. As you drink, alcohol is absorbed through both the stomach and the small intestine. When it enters the blood stream, your blood alcohol concentration (BAC) rises, and you begin to feel drunk. But some people absorb alcohol faster than others, and the same person may absorb it faster or slower in some situations than in others.

Understanding alcohol absorption rate is crucial to defending against a DUI charge, because you may have been legally sober even if you had several drinks—or you may have been over the legal limit even if you barely drank at all.

What are the 12 factors affect my alcohol absorption rate?

Absorption will always occur as soon as you start drinking. It will also continue long after you stop drinking, because alcohol will remain in your stomach and continue to be absorbed for some time. However, the exact rate at which it is absorbed depends on at least twelve factors:

  1. How much you’ve eaten. On an empty stomach your body will begin absorbing alcohol right away, and will do so quickly—potentially going over the legal BAC limit within 30 minutes. Meanwhile, but the liver can only break down about one drink per hour, meaning your body can’t keep up with this rapid intoxication rate. Having a full stomach before drinking always slows alcohol absorption; eating while drinking won’t necessarily help. Protein-heavy food has the biggest impact in slowing alcohol absorption.
  2. Your weight and body type. The less you weight total, the faster you will absorb alcohol. And if two individuals weigh the same amount, but one has a high percentage of body fat and the other has a low percentage, the person with more fat will absorb alcohol faster.
  3. Biological sex. Women’s bodies do not produce as much dehydrogenase, an enzyme that breaks down alcohol in the stomach. As a result, women absorb more alcohol than men, and get a higher BAC.
  4. Menstruation. Hormone levels also affect alcohol absorption, and women will absorb alcohol faster in in the day or so before menstruation.
  5. How fast you drink. Slamming a beer will result in a higher alcohol absorption rate than sipping the same beer over time. This is because the entire amount of alcohol is available for the body to start absorbing immediately. One drink per hour is considered a healthy drinking pace.
  6. How strong the drink is. If you imbibe the same total amount of alcohol as someone else, but you use a stronger drink to do it (say, one shot of whiskey versus one bottle of beer, which both have about the same alcohol content), you will absorb alcohol faster with the whiskey than your friend does with the beer. Similar to drinking fast, this is because more alcohol is available in the stomach sooner, and can be absorbed right away.
  7. Your mood. We all know that drinking has an effect on mood. But it turns out that your mood has an effect on your alcohol absorption, too. Strong stressful emotions like anxiety, anger or depression all have affects on the enzymes in the stomach, leading to faster absorption.
  8. Dehydration. When you’re dehydrated you absorb alcohol at a significantly faster rate. Dehydration also affects the liver’s ability to break alcohol down.
  9. Being sick. When you’re sick, you are typically also dehydrated. People who had a glass of wine after dinner every night and feel fine, for example, may feel incredibly tipsy if they have their glass of wine while they have a cold.
  10. Fatigue. People who are fatigued may absorb alcohol faster than those who are not.
  11. Some health conditions. Diabetes, high blood pressure, seizure disorders, thiamine deficiency, and some other conditions can affect how quickly you absorb alcohol.
  12. Your genes. Some people produce less dehydrogenase than other others, and some people even have genetic deficiencies of these enzymes. This leads to a much higher alcohol absorption rate throughout life.

Is there a difference between alcohol absorption rate and “feeling drunk”?

Yes, and they can go both ways—making you feel more drunk than your BAC should really indicate, or making you feel less drunk than you truly are.

  • Factors that make you feel more drunk include: drinking while on many common kinds of medication (especially cold/flu medicine and painkillers), drinking and taking illegal drugs, fatigue, and expecting or wanting to get drunk. If you set out to get wasted, you will feel wasted quickly even if your blood alcohol is not that high.
  • Factors that make you feel less drunk include: expecting to drink or knowing in advance that you will be drinking, drinking in a physical setting where you are accustomed to drinking, and building up “tolerance” or resistance.

It’s important to know that high alcohol tolerance is a purely behavioral adaptation. In other words, you may feel like you aren’t getting drunk, but you are still losing your ability to think, make decisions and control your body. Feeling sober does not mean you’re safe to drive.

How does alcohol absorption affect my DUI case?

People tend to assume you are intoxicated if you’ve had a certain amount to drink. Police officers make this same assumption. But the truth is, two people could have the same amount to drink and one could be very sober while the other is unsafe to drive. This is because of alcohol absorption rate. If there were factors in your case that would have led to a slow absorption rate, you may not have been impaired at all.

The same thing works in reverse. Let’s say you have absorbing alcohol very slowly. You leave a party to drive home and, if you were tested that exact moment, you’d be under the legal limit and “safe” to drive. But, when police pull you over they wait an hour to conduct a breath or blood test. In that time, your body continued to absorb alcohol and you are now drunker than you were behind the wheel. This defense is known as the rising BAC defense and it can beat a DUI charge.

Have you been charged with DUI? We can connect you with an experienced Los Angeles DUI lawyer and get you a FREE consultation. Fill out the form to the right or call (310) 896-2724 and get your free consultation today. 

Related Frequently Asked Questions