In 30 seconds
- In a meta-analysis of 27 studies, alcohol only clearly shortened the time taken to fall asleep from about 5 drinks upwards.
- With about two drinks, the first REM sleep was already delayed, and on average REM fell by 11 minutes a night.
- In 4,098 adults, overnight recovery measured with heart rate fell by 9.3 points with a little alcohol and by 39.2 with a lot.
- In 14 trials, alcohol increased apnoeas and hypopnoeas during sleep and lowered blood oxygen.
Alcohol does not help you sleep better. It only clearly shortens the time it takes you to fall asleep at about 5 drinks, and with about two it already delays and shortens REM sleep. It also disrupts the second half of the night, raises your heart rate and worsens your breathing while you sleep.
Level of evidence by outcome
| Outcome | Evidence | What the data show |
|---|---|---|
| Less REM sleep | High | Less REM, and later, even at low doses, in a meta-analysis of 27 studies. |
| Falling asleep sooner | Moderate | Only confirmed at high doses, of about 5 drinks or more. |
| Poorer second half of the night | Moderate | Less deep sleep and less REM in the second half, depending on the dose. |
| Higher heart rate and less overnight recovery | Moderate | Dose-dependent effect in 4,098 adults, even with a little alcohol. |
| Breathing during sleep | Moderate | More apnoeas and hypopnoeas and less oxygen in 14 trials. |
| Muscle protein synthesis | Preliminary | 24% less after training, in a trial with 8 men and a high dose. |
The rating is our own, based on the number of studies, their quality and the consistency of the results.
The key studies
| Study | Type | Sample | Outcome |
|---|---|---|---|
| Gardiner et al., 2025 | Meta-analysis | 27 studies with healthy adults | The first REM came 18 minutes later and REM fell by 11 minutes on average, even at low doses. Falling asleep sooner, only with about 5 drinks. 1 |
| Ebrahim et al., 2013 | Review | 20 studies | More deep sleep early in the night; the first REM is delayed at any dose and the second half becomes disrupted. 2 |
| Pietilä et al., 2018 | Observational study | 4,098 employees, average age 45 | Overnight recovery 9.3, 24 and 39.2 points lower with low, moderate and high doses. 3 |
| Kolla et al., 2018 | Meta-analysis | 14 trials, 422 people | 2.33 more apnoeas and hypopnoeas per hour and less blood oxygen; even more in snorers and people with sleep apnoea. 4 |
| Parr et al., 2014 | Crossover trial | 8 active men | A high dose of alcohol after training reduced muscle protein synthesis by 24%, even with protein. 5 |
Alcohol per kilo of body weight
A little alcohol shifts REM; falling asleep sooner takes a lot
Do you fall asleep sooner?
It is the reason many people have a nightcap. A classic review of 20 studies concluded that alcohol shortens the time taken to fall asleep and increases deep sleep in the first half of the night 2.
The most recent meta-analysis, with 27 studies in healthy adults, refines the figure. Taking less time to fall asleep was only confirmed at about 0.85 g of alcohol per kg of body weight, about 5 drinks. And reaching deep sleep sooner, at about 0.95 g per kg 1.
The feeling of dropping off exhausted is real, but it comes with large amounts. And you pay for it later.
REM sleep, the first to pay
REM is the dreaming stage and takes up between 20 and 25% of the night 2. It is the first to suffer:
- It comes later: on average, the first REM was delayed by 18 minutes. This was already noticeable at about 0.35 g per kg, about two drinks 1.
- It lasts less: on average, 11 minutes less REM a night. The drop was clear from about 0.50 g per kg, and each extra gram per kilo took away about 40 minutes 1.
The 2013 review reached the same conclusion by another route: the first REM was delayed at any dose 2.
The second half of the night
Alcohol changes how the night is divided up. In the first 3 hours, with high doses, there was more deep sleep. In the second half, however, deep sleep and REM fell, the latter by between 11 and 17 minutes, more the more people had drunk 1.
That is why it is common to wake up in the early hours after a dinner with wine. You will find more detail in why you wake up at night.
Overnight recovery
More alcohol, less overnight recovery
A higher heart rate and less recovery
A Finnish study used a heart rate sensor to measure the first 3 hours of sleep in 4,098 employees, with an average age of 45, in their real lives. The more alcohol, the higher the heart rate and the lower the overnight recovery 3:
- Low dose (up to 0.25 g per kg): recovery fell by 9.3 points and heart rate rose by 1.4 beats per minute.
- Moderate dose (0.25 to 0.75 g per kg): it fell by 24 points and heart rate rose by 4.
- High dose (more than 0.75 g per kg): it fell by 39.2 points and heart rate rose by 8.7.
And one fact for anyone who trains: exercising regularly or being young did not protect against these effects 3.
To give you an idea of the amounts:
| Alcohol per kg of body weight | For 70 kg | Roughly equivalent to | What was seen |
|---|---|---|---|
| 0.25 g | 17.5 g | A little more than one glass of wine | At this dose or less, overnight recovery already fell by 9.3 points |
| 0.35 g | 24.5 g | About two 330 ml bottles of beer | The first REM sleep already comes later |
| 0.50 g | 35 g | A little more than two glasses of wine | Less REM sleep |
| 0.75 g | 52.5 g | About four 330 ml bottles of beer | Above this, overnight recovery fell by 39.2 points |
| 0.85 g | 59.5 g | About four glasses of wine | Only from here do you clearly fall asleep sooner |
Our own calculation using a 330 ml bottle of beer at 5% (about 13 g of alcohol) and a 150 ml glass of wine at 13% (about 15 g). Effects: Pietilä et al., 2018, and Gardiner et al., 2025.
Breathing during sleep
Extra apnoeas and hypopnoeas after drinking
Snoring and sleep apnoea
A meta-analysis of 14 trials with 422 people found that, after drinking, apnoeas and hypopnoeas, the pauses and dips in breathing, increased by 2.33 per hour. Blood oxygen also fell and the pauses were longer 4.
In people who already snored, they rose by 4.2 per hour, and in people with sleep apnoea, by 7.1. The authors conclude that alcohol can cause or worsen sleep apnoea 4.
If you train: alcohol and muscle
In one trial, 8 active men did a session of strength, cardio and intervals and then drank a high dose of alcohol, 1.5 g per kg, about 12 drinks. Even though they had 25 g of protein when they finished and another 25 g 4 hours later, muscle protein synthesis was 24% lower than without alcohol. Without protein, it was 37% lower 5.
That is a night-out amount, not a single beer. But together with shortened REM sleep and poorer overnight recovery, it points in the same direction. We look at it in sleep and muscle recovery.
What to do with these findings
- No alcohol before bed. This is the recommendation of the American Academy of Sleep Medicine 6.
- Do not use it to fall asleep. The authors of the meta-analysis conclude that it is not a suitable strategy, because what is disrupted later outweighs what you gain 1.
- If you drink, keep it small and well before bedtime. In almost all the studies, people drank in the 3 hours before going to bed, and the effect on REM was already seen at low doses. Whether drinking earlier avoids it altogether is not clear 1.
- If you snore, all the more reason 4.
- On training days, protein and food come first 5.
Swap the drink for a routine
If what you are looking for is a way to switch off in the evening, a drink is not the way. We suggest a step-by-step bedtime routine.
If you sleep badly on an ongoing basis or find it hard to cut down on alcohol, see your doctor.
Frequently asked questions
Does alcohol help you sleep?
It can help you fall asleep sooner, but in a meta-analysis of 27 studies this was only confirmed with about 5 drinks. With much less, about two, REM sleep is already delayed and shortened, and the second half of the night gets worse.
Why do I wake up in the early hours after drinking?
Because alcohol disrupts the second half of the night. At first there is more deep sleep, but afterwards deep sleep and REM fall, and the first REM is delayed at any dose.
How many hours before bed should you stop drinking alcohol?
There is no proven figure. In almost all the studies, people drank in the 3 hours before going to bed, and REM was already disrupted at low doses. Sleep specialists recommend not drinking alcohol before bed.
Does alcohol affect muscle recovery?
In one trial, a high dose of alcohol after training reduced muscle protein synthesis by 24%, even with protein. It also raises your heart rate and reduces recovery during sleep.
Sources
- Gardiner C, Weakley J, Burke LM, Roach GD, Sargent C, Maniar N, Huynh M, Miller DJ, Townshend A, Halson SL. The effect of alcohol on subsequent sleep in healthy adults: a systematic review and meta-analysis. Sleep Med Rev. 2025;80:102030. View publication
- Ebrahim IO, Shapiro CM, Williams AJ, Fenwick PB. Alcohol and sleep I: effects on normal sleep. Alcohol Clin Exp Res. 2013;37(4). View publication
- Pietilä J, Helander E, Korhonen I, Myllymäki T, Kujala UM, Lindholm H. Acute effect of alcohol intake on cardiovascular autonomic regulation during the first hours of sleep in a large real-world sample of Finnish employees: observational study. JMIR Ment Health. 2018;5(1):e23. View publication
- Kolla BP, Foroughi M, Saeidifard F, Chakravorty S, Wang Z, Mansukhani MP. The impact of alcohol on breathing parameters during sleep: a systematic review and meta-analysis. Sleep Med Rev. 2018;42:59-67. View publication
- Parr EB, Camera DM, Areta JL, Burke LM, Phillips SM, Hawley JA, Coffey VG. Alcohol ingestion impairs maximal post-exercise rates of myofibrillar protein synthesis following a single bout of concurrent training. PLoS One. 2014;9(2):e88384. View publication
- American Academy of Sleep Medicine. Healthy sleep habits. Sleep Education. View publication
Information based on published studies. It does not replace the advice of a doctor or registered dietitian. The results describe what was measured in each study, not the properties of any specific product. A varied and balanced diet and a healthy lifestyle are important.
