Nightcaps may fragment sleep and contribute to insomnia and snoring

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Updated on January 12, 2020

If you drink alcohol late and have trouble falling or staying asleep, symptoms that characterize insomnia, you might wonder how long you should wait between your last drink and going to bed. Whether it is beer, wine, or hard liquors, learn how much time should elapse after your last drink before bedtime and what symptoms you might experience if you don’t wait long enough before going to sleep.

The Complicated Relationship Between Alcohol and Sleep

One of the most widely consumed beverages in the world, alcohol has been a part the diets of nearly all existing cultures for millennia. In days of old, it helped to ensure water safety. Alcohol is most often consumed in beer, wine, and hard liquors like vodka, rum, gin, whiskey, and others. It is more often consumed at night and may have an important impact on sleep.

Alcohol has a dual relationship with sleep: It can make us feel sleepy initially while intoxicated, and it can disturb our sleep as it wears off.

The former characteristic led to alcohol’s frequent use as a nightcap, meant to assist in the transition to sleep. It enhances the brain's levels of adenosine, which can make us feel more sleepy. When someone drinks too much alcohol, they are likely to "pass out" due to its effects.

There are other impacts of alcohol on sleep. Alcohol is also a muscle relaxant. This can contribute to relaxation of the airway and worsen snoring and obstructive sleep apnea. In addition, alcohol has a short half-life, meaning that it wears off quickly. As the blood alcohol levels drop, decreasing through metabolism by the liver, this can contribute to sleep fragmentation and awakenings. It is also known that alcohol can suppress REM sleep.

How Long to Wait Between Your Last Drink and Bedtime

It is recommended that alcohol not be consumed in the last 4 hours before bedtime.

Even though alcohol may help you fall asleep, it interferes with the quality of your sleep. In fact, after drinking most people will experience frequent awakenings, night sweats, nightmares, and headaches. What's more, binge drinking can impact your melatonin levels for up to a week afterwards.

As a general rule of thumb, it takes one hour for one serving of alcohol to be metabolized. Therefore, if you have a couple of drinks, you will want the last to be at least several hours before bedtime to avoid impacting your sleep.

If you have difficulty sleeping and note that you sleep better when you don't drink, you might consider stopping alcohol use entirely.

If despite changing when you consume alcohol you continue to have difficulty falling or staying asleep, speak with a sleep specialist about ways to help you to sleep better. It may be important to treat insomnia or sleep apnea if it is present.