How Alcohol Effects Us: The Biphasic Curve Shows the Pleasure vs Pain Relationship

Most people know that a few drinks make them feel good. So they assume that a lot of drinks will make them feel even better. But that’s not true. Although a few drinks will make them feel better, more will make them feel worse. That is the biphasic effect or the biphasic curve. And the biphasic curve describes it visually. (Biphasic refers to its two phases or parts.)

The Biphasic Curve

Here’s what happens. Generally speaking, people tend to feel better as their blood alcohol concentration (BAC) rises to about 0.05. ¬†Specifically, it’s 0.055 to be exact. That is the first phase or part of the biphasic curve.

If people drink more and their BAC rises above .055, the negative effects of drinking increase and hangovers become worse. Problems associated with drinking too much increase. That is the second phase. So it’s clearly smart to stop during the first phase and not progress into the second phase.

biphasic curvebiphasic curve

On the whole, how much does it take to reach a BAC of about .05? The following charts provide guidelines. However, gender, speed of drinking, food eaten, and some medications effect BAC.

Number of
Drinks Per Hour
Body Weight in Pounds
% of Alcohol in Bloodstream
Impaired Intoxicated in all States
Number of Drinks Per HourBody Weight in Pounds
% of Alcohol in Bloodstream
Impaired Intoxicated in all States
How to Maintain a Moderate BAC

Here are some hints for maintaining a moderate blood alcohol concentration.

    • biphasic curveThe first thing to remember is this. The typical can of beer, glass of wine, or liquor drink has the same amount of pure alcohol. Specifically, its 0.60 ounce. Thus, when it comes to alcohol, a drink is a drink is a drink. And they’e all the same to a breathalyzer. For more, visit Standard Drinks and Alcohol Equivalence. Why They’re Important.
    • Know your limit. Most people find that they can have one drink per hour without any ill effects. That is a good rule of thumb. Also, experiment with The Drink Wheel.
    • Eat food while you drink. Food helps slow the absorption of alcohol into your body.
    • Sip and savor your drinks.
    • Don’t participate in “chugging” contests or other drinking games.
    • Accept a drink only when you really want one. If someone tries to force a drink on you, ask for a non-alcohol beverage instead. If that doesn’t work, “lose” your drink by setting it down somewhere and leaving it.
    • Alternate beverages. Have a non-alcoholic drink between alcoholic ones. This helps keep your BAC level down. So does spacing out your alcoholic drinks.
    • Keep active. Don’t just sit around and drink. If you stay active you tend to drink less. Also, you tend to be more aware of any effects alcohol may be having on you.
    • Beware of unfamiliar drinks. Some drinks, such as punches, can be deceiving. That is because the alcoholic content isn’t clear. Therefore, it is difficult to space them properly.
    • Use alcohol carefully in connection with mds. Read the labels carefully. Of course, follow any instructions about drinking alcohol with the medication.

Needless to say, drinking too much alcohol is never a good idea.

Popular Resources on Drinking

Dasgupta, A. The Science of Drinking. How Alcohol Affects Your Body and Mind. Lanham, MD: Rowman & Littlefield, 2012.

Michael, E. Moder8: Balance for a Better Life. How to Control Your Drinking and Learn to Drink in Moderation. Michael, 2012.

Poikolainen, K. Perfect Drinking and Its Enemies. Minneapolis: Green, 2014. And

Turner, C. Can I Keep Drinking? How You can Decide When Enough is Enough. NY: Morgan James, 2017.

Technical Articles on the Biphasic Curve
  • Erblich, J., et al. Biphasic stimulant and sedative effects of ethanol. Are children of alcoholics really different? Addict Behav, 2003, 28(6), 1129-1139.
  • King, A., et al. Biphasic alcohol response differs in heavy versus light drinking. Alco Clin Exper Res, 2002, 26(6), 827-835.
    1. Graphics for biphasic curve are from the Alcohol & drug Counseling, Assessment, and Prevention Service at Washington State University. It adapted them from Brief Alcohol Screening and Intervention for College Students (BASICS) by Linda Dimeff et al. It also adapted them from the work of Dr. Pat Fabiano at Western Washington University.
    2. Tables adapted from the  National Clearinghouse for Alcohol and Drug Information and the Iowa Alcoholic Beverages Division.
    3. At this point you know about the biphasic curve and its importance. few people have even heard of it. So congratulations!
    4. Perhaps you know of an item that should be on this page. If so, please contact hansondj [@] potsdam [.] edu/. In fact, many readers have helped improve this site. So thank you for any help.