All articles

Does alcohol disrupt sleep?

Last updated: October 15, 2026

Yes. Alcohol helps you fall asleep faster, but at every dose studied it disrupts the second half of the night, and moderate to high doses reduce REM sleep.

The two halves

Early in the night, alcohol acts as a sedative: you fall asleep faster and the first half of sleep is more consolidated, with more deep sleep. As your body clears the alcohol, the second half of the night becomes more disrupted (Ebrahim et al., 2013).

REM suppression

Alcohol delays your first REM period at every dose studied, and moderate to high doses reduce total REM sleep across the night (Ebrahim et al., 2013). REM sleep plays a role in memory, so losing it is not a free trade (Diekelmann & Born, 2010).

Practical rule

Avoid alcohol before bedtime, as both the CDC and the American Academy of Sleep Medicine advise. If you drink in the evening, keep it moderate and early: the less alcohol is in your system at bedtime, the less it can disturb the second half of your night.

Sources

1. Matthew Walker, Why We Sleep (Scribner, 2017). Why We Sleep: Unlocking the Power of Sleep and Dreams
2. Ebrahim et al., Alcoholism: Clinical and Experimental Research, 2013. Alcohol and sleep I: effects on normal sleep
3. Diekelmann & Born, Nature Reviews Neuroscience, 2010. The memory function of sleep
4. Centers for Disease Control and Prevention. CDC — Sleep and Sleep Disorders
5. American Academy of Sleep Medicine. Healthy Sleep Habits (Sleep Education)