What does alcohol do to my sleep quality, and is there anything I can do about it?

Alcohol may seem to make falling asleep easier, but that impression is deceptive. You fall asleep faster and sleep feels deeper during the first part of the night. As soon as your body has broken down the alcohol, however, that effect reverses. In the second half of the night your sleep becomes disrupted and lighter. On balance, alcohol therefore harms your sleep, even if it initially feels otherwise¹.

In people who structurally drink too much or are alcohol-dependent, the damage goes further. There is persistently less deep, restorative sleep and a disrupted REM-sleep pattern. Worryingly, these disruptions last a long time, even well into periods of abstinence, and may contribute to relapse into drinking behaviour¹.

There is also a reverse dynamic at play. Poor sleep can itself cause you to use more alcohol, presumably as self-medication. This creates a vicious cycle: alcohol disrupts your sleep, and sleeping worse increases the urge to drink. This relationship is for now associative, not a proven cause-and-effect relationship, but the pattern is recognisable.

The most direct approach is to reduce alcohol or at least stop drinking shortly before bedtime. For nutritional support there are cautious indications: tryptophan (milk, eggs), omega-3 fatty acids (oily fish), vitamins B6, B12 and D, and minerals such as magnesium and zinc are associated with better sleep²,³. However, this is observational research. There is no evidence that these nutrients counteract sleep problems caused by alcohol.

Glycine, an amino acid that occurs naturally in the body, is described in a narrative review as potentially sleep-promoting⁴. However, the evidence is thin and insufficient for concrete recommendations. Glycine supplements are not a proven remedy for alcohol-related sleep disruption.