Numerous studies show a link between alcohol and impotence, or erectile dysfunction (ED), in men. Alcohol and impotence go hand in hand, because alcohol damages the nervous system and reduces the production of testosterone and other hormones necessary for sexual arousal. Long-term alcohol abuse can lead to irreversible ED, in which a man cannot get or maintain an erection long enough to have sex. To avoid this condition and other health problems that indirectly cause impotence, medical experts say men under 65 should limit their alcohol intake to one or two "standard drinks" a day.

Drinking several beers in succession can cause temporary impotence, because it slows down the functioning of the nervous system. For a man to get an erection, nerve cells must send the message — from the hypothalamus to the anterior pituitary gland to the penis — that more blood should flow into the penis, making it larger and stiffer. Alcohol slows down communication between nerve cells, interfering with the delivery of the message.

Long-term alcohol abuse can adversely affect every step of a man's sexual functioning. It can prevent a man from feeling much sexual desire at all, because it reduces the production of the hormone testosterone. Even if sexual desire remains, alcohol-damaged nerve cells may be unable to communicate with the penis. Even if the penis does receive the "erection" message, alcohol-damaged blood vessels inside the penis may be unable to fill up normally.

Alcohol abuse simply means drinking more alcohol than is good for your health. Medical experts say men under 65 should not drink more than three standard drinks in one day. This means men should not exceed three standard drinks in any single 24-hour period. Binge drinking followed by days of no drinking, for an average of three drinks a day does not prevent the alcohol and impotence link from forming.

A standard drink is one 12-ounce (350 mL) can of beer, 4 ounces (120 mL) of wine, 1.5 ounces (45 mL) of 80-proof spirits, or 1 ounce (30 mL) of 100-proof spirits. The popular 40-ounce (1.2 liter) bottle of beer contains more than three standard drinks, so finishing just one of them in an evening is too much. According to doctors and researchers, men who limit their alcohol intake to just one or two standard drinks or less in a day have the best chance of avoiding the connection between alcohol and impotence.

Alcohol-induced erectile dysfunction can be irreversible, but treatments sometimes succeed at curing, or at least reducing, the frequency of ED. Treatment options include vacuum devices, hormone replacement, and drugs such as Viagra. Treatment options may be restricted by other alcohol-induced health conditions. For example, alcohol abuse can damage the heart, and Viagra cannot be used on men with heart problems.