Many people have experienced falling asleep faster after drinking alcohol. However, this does not mean they sleep better. While alcohol may shorten the time it takes to fall asleep, it disrupts sleep structure, reduces rest quality, and leads to more frequent awakenings, especially in the second half of the night.
Sleep consists of repeating cycles alternating between NREM and REM sleep. In adults, one sleep cycle lasts approximately 70 to 90 minutes and repeats several times during the night.
NREM sleep makes up most of the night and includes lighter and deeper stages. During this part of sleep, heart rate, breathing, and brain activity slow down, and the body enters a restorative mode.
Deep sleep, also known as N3 or slow-wave sleep, is crucial for physical regeneration, nervous system recovery, and the feeling of truly being well-rested. Alcohol may temporarily increase this phase in the first part of the night but overall destabilizes sleep.
REM sleep is the stage associated with dreaming, memory consolidation, and emotional recovery. Alcohol significantly disrupts REM sleep, particularly its onset and duration, which is one of the main reasons people feel tired after drinking.
Initially, alcohol has a sedative effect, which can induce drowsiness. However, scientific studies repeatedly show that this benefit comes at the cost of poorer sleep quality, greater fragmentation, and disrupted sleep architecture.
In the first part of the night, alcohol may briefly deepen sleep and reduce sleep onset time. But as blood alcohol levels drop, sleep becomes lighter, more fragmented, and less restorative.
From a scientific perspective, alcohol affects several systems that regulate sleep and wakefulness. It alters the balance between inhibitory and activating processes in the brain and interferes with sleep homeostasis mechanisms. Thus, while it may facilitate falling asleep, it subsequently disrupts sleep stability.
Alcohol also impacts melatonin. In a study on healthy volunteers, evening administration of ethanol reduced nighttime melatonin secretion, which can disrupt circadian rhythms and worsen sleep quality.
After alcohol consumption, sleep may be deeper at the beginning of the night but often breaks down in the second half. Awakenings increase, REM sleep shortens, and the body enters a less stable and less restorative state.
This explains why someone may feel unrested in the morning after evening drinking, even if they slept long enough.
Alcohol can worsen snoring and sleep apnea. Review literature indicates it increases breathing disturbances during sleep, prolongs respiratory events, and may reduce blood oxygenation, especially in people with existing issues.
In the short term, alcohol may act as a quick crutch for falling asleep. However, from the perspective of healthy sleep, this is a misleading effect because sleep quality deteriorates, and sleep no longer fulfills its restorative function.
A recent systematic review further shows that even low doses of alcohol negatively affect REM sleep, while higher doses may shorten sleep onset time but at the cost of even greater disruption to sleep architecture.
Alcohol is not suitable as a means to improve sleep. Although it may shorten the time to fall asleep, it simultaneously worsens sleep quality, disrupts the REM phase, promotes nighttime awakenings, and can aggravate breathing during sleep.
If you feel that alcohol, sleep, or your overall lifestyle are affecting your mental well-being, you don’t have to face it alone. At EUNOMA Clinic, a team of psychologists, psychotherapists, addiction specialists, and nutritional therapists works together to identify connections and find a concrete path toward improvement.
I have been working in the field of addiction counselling for more than 10 years. I hold a bachelor’s degree in Addictology from the First Faculty of Medicine and a degree in General Medicine from the Second Faculty of Medicine, Charles University. In my research, I focus on preventive medicine and epidemiology.
In my work with clients, I combine evidence-based knowledge with a holistic approach to mental health. My medical background enables me to understand the broader clinical context and to better support each client’s individual needs.
