The Dangers of Mixing Alcohol & Melatonin

Published On: April 26, 2023

Experiencing consistently high levels of stress and anxiety can cause people to have trouble sleeping, and this has become only too clear over the last few years since the coronavirus pandemic emerged as the number of cases of insomnia and sleep problems has increased significantly. (1)

One important, contributory factor affecting both the quality and quantity of sleep a person has is the amount of melatonin present in their body. (8)

What is melatonin?

Mixing Pills

Melatonin is a hormone that is naturally produced by the pineal gland and controls the sleep-wake cycle and is prominent in ensuring that we get sufficient sleep each evening.

Melatonin plays a key role in facilitating various natural physiological mechanisms associated with the sleep-wake cycle. (8)

How does melatonin work?


The pineal gland is sensitive to any reduction in our surrounding natural light, and as this natural light diminishes the pineal gland releases melatonin in response to the increasing darkness around us that activates physiological processes that help us fall asleep.

Melatonin plays a key role in maintaining our inner body clocks and is linked to many of our circadian rhythms, of which sleep is one.

Melatonin tablets when consumed enhance the body’s current natural supply levels of the hormone which means the body now has enough melatonin to restore the sleep-wake cycle to its natural state.

This is because melatonin can connect to brain receptors that induce a relaxed state in the body when the level of natural light diminishes later in the day to help us to gain a refreshing night’s sleep. (4,5)

Melatonin is a natural substance NOT a psychoactive drug


Even though melatonin is not a psychoactive drug and can be obtained as a supplement in pharmacies, health food shops or ordered online as well as being prescribed it is still a significant hormone that can significantly affect how we function so it should not be taken lightly.

Anyone seeking to take the supplement to improve their sleep should exhibit a degree of care and consideration and show due diligence before taking the hormone.

Hormones generate and deliver biochemical messages throughout the body and are transported via the bloodstream to key organs that initiate various actions and processes, and melatonin is the hormone responsible for governing the sleep-wake cycle.

Some people also use melatonin supplements to help them cope with the negative effects and poor sleeping patterns that result from jet lag. (8,10)

Who should take extra care before taking melatonin?


Anyone considering taking melatonin should conduct thorough research on the hormone and ensure they understand all aspects of their medical history to check they are safe to start a course of melatonin.

It is always best to speak with a doctor or pharmacist if you have any uncertainties about how the hormone will affect you or explore other suitable options available to improve the quality of your sleep.

People who fall into any of the categories below should take extra caution before taking melatonin supplements:

  • Anyone who has previously had an allergic reaction to melatonin or any drug.
  • Individuals diagnosed with diabetes.
  • People who have had significant issues with their liver or kidney.
  • Anyone who has had seizures or is vulnerable to having them.
  • People taking blood-thinning drugs or medication to reduce their blood pressure.
  • Any individual diagnosed with an autoimmune disorder such as rheumatoid arthritis, multiple sclerosis or lupus.
  • Individuals who are taking medication to suppress their immune system after having a major organ transplant.
  • Anyone diagnosed with dementia.
  • Individuals diagnosed with depression.

Anyone that regularly takes other drugs such as benzodiazepines or painkilling drugs such as codeine.

It is however always worthwhile consulting with your GP to confirm if your medical condition is severe enough to be affected by melatonin if you have any doubts. (5,8,10)

How alcohol affects our central nervous system


Alcohol is a central nervous system depressant which means essentially that it will slow down brain activity, the more a person drinks the higher the alcohol concentration in the blood becomes and within a short period of time their brain activity will be slowed down.

Alcohol’s chemical properties affect neurotransmitters called GABA in the brain, neurotransmitters are responsible for sending messages around the body which contain instructions to initiate or inhibit certain physical actions.

The GABA neurotransmitter is responsible for slowing down biological activities related to respiration, consciousness and cognition. Initially, when we drink alcohol we feel relaxed but the more we drink the more drowsy we begin to feel.

However, if people continue to drink a lot of alcohol in a short space of time they are likely to pass out or slip into a coma, or even stop breathing.

Alcohol enhances the effect of GABA, which means it will slow down brain activity at a greater rate than it would have done if alcohol was not consumed. (3,7)

How alcohol affects sleep


Initially, alcohol has a sedative effect when consumed and people may fall asleep easily after drinking, however, these effects do not last for long and eventually, alcohol will disrupt sleep as the chemicals in alcohol will interact with brain neurotransmitters that are involved in maintaining the sleep cycle.

When people start to sleep after a period of drinking their blood alcohol levels will continue to rise as the body can only process one standard drink per hour, which means within a few hours the quality of their sleep will deteriorate and become disrupted.

As a result of this, they will probably not pass through the natural sleep cycle into REM sleep which is important for memory processes, improving our emotional health and ensuring healthy brain functioning.

Excessive drinkers are highly likely to have severe sleep disruption and the nature of their sleep will be drastically altered and qualitatively different to the natural sleep-wake cycle.

This is because the key neurotransmitters that play a vital role in maintaining mechanisms that control the sleep cycle have been affected by alcohol. (3,4,7)

There is a complicated relationship between alcohol and the sleep cycle

Man lying down with his hand over his head

Alcohol as a central nervous system depressant is notorious for disturbing people’s sleep patterns and insomnia is one of the withdrawal symptoms associated with alcohol dependence.

Firstly, it is important to establish your relationship with alcohol before considering taking melatonin to treat your sleep problems.

If you regularly drink over 30 units of alcohol per week then it is unlikely that taking melatonin will help you sleep and you should seek to cut down your alcohol intake, as it is more than likely that this is the main reason you are unable to get a good night’s sleep.

If you take melatonin and continue to drink alcohol the alcohol will render the melatonin ineffective and you will cause yourself physical harm due to the powerful interaction effects generated when melatonin and alcohol are consumed together.

It is unwise to take melatonin for your insomnia until your excessive drinking is brought under control again if not ceased altogether. If you are struggling to do this then you should visit your GP so that he/she can refer you for treatment for alcohol dependence (or addiction). (3,4)

Long terms effects of alcohol on melatonin and the sleep cycle


Research has indicated that excessive alcohol consumption can affect the amount of melatonin the body naturally produces.

Experimental research has shown that individuals dependent on alcohol show reduced levels of melatonin when tested in the early part of the night, which leads to a delay in the release of sufficient melatonin to help them sleep.

It has been proposed that alcohol contains chemicals that both reduce the natural production of melatonin and limit its ability to work effectively to ensure a good night’s sleep.

Physical effects of combining alcohol with Melatonin

Woman sleeping

As well as severely limiting the effects of the melatonin produced in the human body anyone who consumes alcohol within a couple of hours of taking melatonin may experience the following symptoms:

  • An elevated heart rate.
  • A reddish facial appearance.
  • The hands and feet will become swollen.
  • Disrupted sleep patterns.
  • Anxiety and irritability are likely to develop or become more pronounced.
  • Unpleasant dreams.
  • It can negatively impact our cognition leading to a confused state.
  • Feeling dizzy.
  • Drowsiness
  • Feeling nauseous.
  • An increased risk of falling / collapsing due to constant tiredness and drowsiness
  • Difficulty with breathing
  • Suddenly becoming unconscious. (5,6,8)

A word of caution


These physical effects of combining alcohol with melatonin can have disastrous consequences in many areas of people’s lives so anyone taking melatonin should be very mindful of the effects of drinking any alcohol, regardless of the amount if they decide to take melatonin to help them sleep better.

People considering melatonin as an option to help them sleep need to maintain a high degree of discipline to avoid alcohol at all costs during the 1-2 months they are taking the supplement.

Alcohol and melatonin – Harmful interactions

A mocktail with a slice of orange and straw

There are uncertain and harmful interaction effects when consuming melatonin and alcohol close together.

Melatonin and alcohol both possess chemicals that will depress the central nervous system, so drinking alcohol and taking a hormone supplement that will enable you to sleep will mean that you are doubly decreasing your brain activity.

The melatonin will prepare the body for sleep by slowing down certain mechanisms related to physical activity and consciousness and setting the tone for restfulness to occur, and the alcohol will inhibit brain activity related to the respiratory system and consciousness.

One of the consequences of this is that it may affect a person’s ability to carry out tasks the following day that require a high degree of skill and/or concentration.

This may include:

  • Operating machinery/equipment.
  • Analytical work.
  • Responsible tasks that require intense concentration and attention, including air traffic controadults looking after children.l operators, medical practitioners and

Airline pilots who may take melatonin to combat jet lag need to be extra careful with their alcohol intake if they regularly take the hormone to help deal with jet lag during their busy work schedule to ensure they are fully refreshed before their next flight. (9,10)

Melatonin and alcohol – key points

People at a table toasting to a mix of drinks

It is definitely NOT advisable to drink alcohol whilst you are taking melatonin.

Medical advice suggests it is not wise to use melatonin for prolonged periods, the recommended period for use is 1 month but it is certainly not advisable to take it for longer than two months.

It would be wise not to drink alcohol during the period you are taking the hormone supplement to ensure that there are no negative consequences as it is difficult to predict the specific effects it will have on any one person as we all have a unique physiological make-up.

Drinking alcohol and taking melatonin can make people feel groggy and dizzy and can affect them the next day, possibly leading to a decline in their alertness and cognitive abilities.

Consult with a pharmacist or GP before ordering melatonin supplements or if you are already taking it and are feeling groggy.

It may also be necessary to consult with a medical professional if you are uncertain about the dose size, how often you take the supplement and how long you take it for

Ensure you eat food when you take your melatonin supplement to ensure it takes effect as efficiently as possible.

Never take more than the dose size recommended by your GP or pharmacist, if you do forget to take your usual dose one evening do NOT take a double dose the next night.

It is recommended to take melatonin in small doses for around an hour or two before going to bed. The recommended dose size is 1-3 mg. (8,9)

Mixing melatonin and alcohol

Man with his head in his hand, eyes closed, in a gesture of pain

If you do drink alcohol while taking melatonin leave at least a three-hour gap in between. Melatonin should be taken between 1-2 hours before bedtime and it would be unwise to drink alcohol after that otherwise you will feel very groggy the next day and there will be a decline in your cognitive abilities. (3,5,8,9)

If you go to bed at 10 pm, then you would take melatonin between 8 and 9 pm, therefore to minimise the interaction effect between the two you should not drink alcohol after 5 pm or 6 pm.

However, it must be stressed it would be better not to drink any alcohol at all while taking melatonin supplements during the 1-2 month period you are taking the hormones for.


(1) BBC News (2022) The ‘coronasomnia’ phenomenon keeping you from getting sleep. available@The ‘coronasomnia’ phenomenon keeping you from getting sleep – BBC Worklife

(2) Black, D., Grant, J. (2013) DSM5 Guidebook: The Essential Companion to Diagnostic and Statistical Manual of Mental Disorders, 5th Edition. APP. London.

(3) Camden and Islington NHS Trust (2022) The Unhealthy mix between alcohol and mental health. Available@ The unhealthy mix between alcohol and mental health | Camden and Islington NHS Foundation Trust (

(4) Colrain, I. et al (2018) Alcohol and the sleeping brain. available@Alcohol and the Sleeping Brain – PMC (

(5) Ferracioli-Oda, E. (2013) Meta-Analysis: Melatonin for the treatment of primary sleep disorders. available@ Meta-Analysis: Melatonin for the Treatment of Primary Sleep Disorders | PLOS ONE

(6) Kuhlwein, E. et al (2003) Abnormal Nocturnal melatonin secretion and disordered sleep in abstinent alcoholics. available@abnormal nocturnal melatonin secretion and disordered sleep in abstinent alcoholics – ScienceDirect

(7) Kuria, M.W. et al (2012) The Association between alcohol dependence and depression before and after treatment for alcohol dependence. available@The Association between Alcohol Dependence and Depression before and after Treatment for Alcohol Dependence – PMC (

(8) National Health Service (2022) Melatonin. available@ Melatonin: a manmade hormone used for short-term sleep problems – NHS (

(9) National Institute for Care Excellence (2022) Melatonin: Interactions. available@ Melatonin | Interactions | BNF | NICE

(10) North Central London NHS (2019) Melatonin Fact Sheet. available@Melatonin fact sheet (

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