Obesity medicines and alcohol - can you drink during treatment?

The official product information for semaglutide (Wegovy, and also Ozempic, which is a medicine for type 2 diabetes), tirzepatide (Mounjaro) and liraglutide (Saxenda) does not mention alcohol in either the interactions or the warnings section. This does not mean that drinking alcohol during treatment is safe. These medicines can cause acute pancreatitis, and alcohol also increases the risk of this disease. With Mysimba, a combination of naltrexone and bupropion, the rules are different. While taking it, you are advised to keep alcohol to a minimum or avoid it completely, and someone who is dependent on alcohol must not start Mysimba immediately after suddenly stopping drinking. We advise not drinking any alcohol at all for the whole of your obesity treatment, whatever the medicine. Anyone who drinks every day or cannot stop drinking should tell their doctor before the first dose, because their drinking may need separate treatment, running alongside the obesity treatment.

In brief

• The official information for Wegovy, Ozempic, Mounjaro and Saxenda does not mention alcohol, but that is no proof that drinking while taking these medicines is safe. World Health Organization experts write that no level of drinking can be considered safe for health. This is why we advise not drinking alcohol at all for the whole of your treatment.
• Semaglutide, tirzepatide and liraglutide slow down stomach emptying, so in the first minutes after drinking, alcohol may reach the blood more slowly and feel weaker. So far, this has been shown in only one small preliminary study. This means it is hard to tell from how you feel how much alcohol will be in your blood shortly afterwards.
• Mysimba contains bupropion, which increases the risk of seizures. It must not be used by people who usually drink a lot of alcohol, have just stopped drinking or plan to stop during treatment, or who take naltrexone for another reason.
• Anyone who has been drinking large amounts of alcohol every day for a long time should not stop suddenly on their own. An obesity medicine does not treat alcohol dependence, so dependence is treated separately, alongside obesity.

What does the official information on semaglutide, tirzepatide, liraglutide and Mysimba say about alcohol?

The current official product information for Wegovy, Ozempic, Mounjaro and Saxenda, meaning the document approved when the medicine was authorised, says nothing at all about drinking alcohol (1, 2, 3, 4). Of the five medicines discussed here, only Mysimba has advice about alcohol in its official information (5).

Ozempic and Wegovy contain the same substance, but Ozempic is licensed only for treating type 2 diabetes, not obesity. In people with diabetes who take insulin or a sulfonylurea in addition to semaglutide or tirzepatide, the risk of hypoglycaemia, meaning blood glucose that is too low, increases (2, 3). We describe how alcohol affects blood sugar in diabetes in our article on diabetes and alcohol.

Does the lack of an alcohol warning mean you can drink on semaglutide?

No. The official information on semaglutide, tirzepatide and liraglutide does not describe how alcohol and the medicine act together, but it does not promise that drinking during treatment is harmless either. The same information warns about acute pancreatitis and dehydration, and alcohol increases the risk of pancreatitis regardless of the medicine. World Health Organization (WHO) experts also write that no level of drinking can be considered safe for health, because studies have not found a threshold below which alcohol does not increase the risk of cancer (6). This is why we advise not drinking any alcohol during obesity treatment, including at family celebrations.

Does alcohol affect you differently on semaglutide or tirzepatide?

A small study suggests that alcohol may be absorbed more slowly while you are taking these medicines, but this result needs to be confirmed. Semaglutide, tirzepatide and liraglutide slow down stomach emptying, and alcohol is absorbed into the blood mainly in the upper part of the intestine, not in the stomach (7). This is why, on the medicine, alcohol may reach the blood later, and in the first minutes after drinking you may feel it less.

Tirzepatide slows stomach emptying most at the start of treatment (3). With longer use of semaglutide at a dose of 2.4 mg, on the other hand, no clinically relevant delay in stomach emptying was found. The body probably adapts to this effect over time (1).

US researchers looked at whether semaglutide, tirzepatide and liraglutide change the effects of alcohol in a small preliminary study of 20 people with obesity who drank alcohol occasionally (7). Ten of them had been taking a maintenance dose of one of these medicines for at least 4 weeks (six semaglutide, two tirzepatide and two liraglutide), and ten were not taking any obesity medicine. Within an hour, each participant drank three vodka and juice drinks, with the amount of alcohol chosen so that their blood alcohol concentration reached about 0.1% (1 per mille, the unit used in Poland). In the people taking a medicine, the alcohol concentration in their breath rose more slowly for the first 20 minutes. They also rated themselves as feeling slightly less drunk, but this difference was not statistically significant at any single measurement. Between 35 and 60 minutes, the difference in concentrations between the groups was no longer significant either. Participants were not randomly assigned to the groups, and the groups were small, so the result should be treated with caution.

The result is preliminary, but it suggests that on the medicine, how you feel right after drinking may not reflect how much alcohol will be in your blood shortly afterwards. You must not drive after drinking alcohol, whether or not you are taking any medicine.

Why is vomiting after drinking risky on an obesity medicine?

Nausea, vomiting and diarrhoea are among the most common side effects of semaglutide, tirzepatide and liraglutide. With semaglutide and tirzepatide, they occur mainly in the weeks when the doctor increases the dose. Vomiting and diarrhoea cause fluid loss, and in rare cases dehydration impairs kidney function or even leads to acute kidney failure (1, 3, 4). If you vomit after drinking alcohol, you lose even more fluid.

How does alcohol affect the pancreas and liver during obesity treatment?

Acute pancreatitis is an uncommon but serious side effect of semaglutide, tirzepatide and liraglutide, and alcohol also increases the risk of this disease. In people with obesity, the liver is often already fatty, and with liver disease there is no safe amount of alcohol.

Does drinking alcohol on an obesity medicine increase the risk of pancreatitis?

The official product information does not say how much drinking alcohol increases the risk of pancreatitis during treatment. It only describes the risk linked to the medicine itself. According to the patient leaflets, acute pancreatitis may affect up to 1 in 100 people taking semaglutide, tirzepatide or liraglutide (1, 3, 4). In phase III trials of semaglutide for obesity, doctors confirmed acute pancreatitis in 0.2% of people taking the medicine and in less than 0.1% of those taking placebo, and in the large SELECT trial in 0.2% and 0.3% respectively (1).

Alcohol increases the risk of pancreatitis even in people who are not taking any medicines. According to a review of studies in the general population, if people drank less alcohol, there would be almost a fifth fewer cases of pancreatitis, and if everyone had a healthy body weight, almost a quarter fewer (8). Someone with obesity who drinks alcohol therefore has two risk factors for pancreatitis before treatment even starts.

Why should you not drink alcohol if you have fatty liver?

Metabolic dysfunction-associated steatotic liver disease (MASLD) affects 70-80% of people with obesity (9). The Polish Society for the Treatment of Obesity (PTLO) advises people with MASLD not to drink alcohol at all, because with liver disease there is no safe dose of alcohol. With advanced liver fibrosis, you need to give up alcohol completely. For many people being treated for obesity, this is a reason not to drink alcohol, whatever medicine they take. We describe how alcohol damages the liver in our article on alcohol-related liver disease.

Can you drink alcohol on Mysimba?

During treatment with Mysimba, you are advised to keep alcohol to a minimum or avoid it completely (5). The main reason is bupropion, one of the medicine's two ingredients, because it increases the risk of seizures.

The risk of a seizure depends on the dose of bupropion. In clinical trials of Mysimba, 2 of the 3,239 people taking the medicine (about 0.06%) had a seizure, and none of the 1,515 people given placebo did. The risk is increased by, among other things, alcohol misuse, a previous head injury, cocaine dependence and medicines that lower the seizure threshold. Excessive drinking during treatment can also cause episodes of psychiatric disturbance and make the body less tolerant of alcohol (5).

Although Mysimba contains naltrexone, it is not a medicine for alcohol dependence: it is licensed only for treating obesity and overweight. For alcohol dependence, naltrexone is prescribed as a separate medicine, and anyone taking it must not use Mysimba at the same time.

Who should not take Mysimba if they drink?

Mysimba must not be used by people who (5):

• are dependent on alcohol and have just suddenly stopped drinking (the same applies to suddenly stopping benzodiazepines, a group of sedatives)
• usually drink a lot of alcohol, have only just stopped drinking or plan to stop drinking while taking Mysimba
• take naltrexone or bupropion for another reason, for example naltrexone to treat alcoholism
• have epilepsy or have ever had a seizure
• have severe liver disease
• are dependent on opioids or are being treated with methadone or buprenorphine

If you are already taking Mysimba and drink heavily, you should not stop drinking suddenly, because this can increase the risk of an epileptic seizure (5). Discuss this situation straight away with the doctor who prescribed the medicine.

Obesity medicines and alcohol - when do you need urgent medical help?

Severe abdominal pain and signs of dehydration need urgent medical assessment. If you have a seizure, hallucinations or confusion after stopping alcohol, call an ambulance. You should not wait for your scheduled check-up.

• Severe, persistent abdominal pain, which may spread to the back, can mean acute pancreatitis. You need to contact a doctor immediately and not take your next dose of the medicine until the doctor has assessed you. If the doctor confirms pancreatitis, you should not go back to that medicine (1, 3, 4). We write more about this kind of pain in our article on pancreatic pain after alcohol.
• Vomiting that stops you keeping fluids down, passing small amounts of dark urine or feeling dizzy when you stand up can mean dehydration, and dehydration can impair kidney function. Contact a doctor the same day.
• If someone has a seizure, call an ambulance urgently. If it happened during treatment with Mysimba, the medicine needs to be stopped and not started again (5).
• If you have seizures, hallucinations or confusion after stopping alcohol, call an ambulance immediately. The most severe form of withdrawal syndrome is life-threatening.

What should you do if drinking is a problem and you want obesity treatment?

Before you start obesity treatment, tell your doctor how much alcohol you drink and how often. If your drinking is getting out of control, it needs to be treated separately, alongside obesity, because no obesity medicine is licensed to treat dependence.

Someone who has been drinking large amounts of alcohol every day for a long time should not stop suddenly on their own, for example on the day of their first dose of an obesity medicine. Up to half of people who have been drinking heavily for a long time develop withdrawal symptoms, known as withdrawal syndrome, after stopping or sharply cutting down on alcohol. Its most severe form is life-threatening (10). They should stop drinking under medical supervision, if necessary during alcohol detox. We describe withdrawal symptoms in our article on withdrawal syndrome.

Alcohol dependence is treated with psychotherapy and medicines for alcoholism, and alcohol addiction treatment can take place at the same time as obesity treatment. If you are already taking a medicine for alcoholism, such as disulfiram (Esperal, Anticol) or naltrexone, tell your doctor before you start obesity treatment. The doctor will take this into account when choosing an obesity medicine, because, for example, taking naltrexone rules out Mysimba.

In our obesity treatment programme, the doctor assesses your BMI, waist circumference and blood tests and then, following Polish guidelines, decides whether to prescribe a medicine. If a patient's drinking is hazardous, we also refer them to our addiction treatment clinic at the same time. This article does not replace a medical consultation.

Frequently asked questions

Is alcohol less harmful on the lowest dose of Wegovy or Mounjaro?

There are no data showing that drinking alcohol on the starting dose is any safer. The warnings about pancreatitis and dehydration with semaglutide and tirzepatide apply to all doses, not only the higher ones (1, 3). Tirzepatide slows stomach emptying most at the start of treatment, and nausea and vomiting occur mainly in the weeks when the dose is being increased. On the starting dose (0.25 mg of semaglutide, 2.5 mg of tirzepatide), the advice is therefore the same as on any other: the safest option is not to drink alcohol at all.

Can you stop your obesity medicine for a few days to drink at a wedding?

No. A few days' break does not clear the medicine from your body. The half-life of semaglutide, meaning the time it takes for the level of the medicine in the blood to fall by half, is about a week, and after the last 2.4 mg dose, semaglutide stays in the blood for about another 7 weeks. The half-life of tirzepatide is about 5 days (1, 3). Alcohol puts a strain on the pancreas and liver whether or not the medicine is still in your body. A break also makes the treatment itself harder: if a patient misses several doses of semaglutide, the doctor considers restarting at a lower dose (1), and the dose then has to be increased gradually again. At a wedding, the safest option is not to drink alcohol at all and to keep taking the medicine without breaks, as your doctor prescribed.

Does the Mounjaro KwikPen contain alcohol?

Yes, each dose from the Mounjaro KwikPen contains 5.4 mg of benzyl alcohol. Benzyl alcohol is an inactive ingredient of the medicine, not the ethyl alcohol found in beer, wine or vodka. Its presence does not change the rules on drinking alcohol during treatment. It can, however, cause an allergic reaction. Women who are pregnant or breastfeeding and people with kidney or liver disease should ask their doctor about this ingredient, because in large amounts benzyl alcohol can build up in the body (3).

Do obesity medicines reduce the urge to drink?

In a phase II trial, 48 people with alcohol use disorder took low doses of semaglutide or placebo for 9 weeks. Those taking semaglutide had weaker alcohol cravings and drank less on the days they drank, but the number of drinking days did not change significantly (11). No obesity medicine is licensed to treat alcohol dependence. We write more about these studies in our article on semaglutide and alcohol dependence.

Sources

1. Charakterystyka Produktu Leczniczego Wegovy (semaglutyd), roztwór do wstrzykiwań i tabletki. Europejska Agencja Leków, informacja o produkcie w języku polskim. ema.europa.eu
2. Charakterystyka Produktu Leczniczego Ozempic (semaglutyd), roztwór do wstrzykiwań. Europejska Agencja Leków, informacja o produkcie w języku polskim. ema.europa.eu
3. Charakterystyka Produktu Leczniczego Mounjaro (tirzepatyd), roztwór do wstrzykiwań. Europejska Agencja Leków, informacja o produkcie w języku polskim. ema.europa.eu
4. Charakterystyka Produktu Leczniczego Saxenda (liraglutyd), roztwór do wstrzykiwań. Europejska Agencja Leków, informacja o produkcie w języku polskim. ema.europa.eu
5. Charakterystyka Produktu Leczniczego Mysimba (naltrekson z bupropionem), tabletki o przedłużonym uwalnianiu, wraz z ulotką dla pacjenta. Europejska Agencja Leków, informacja o produkcie w języku polskim. ema.europa.eu
6. Anderson BO, Berdzuli N, Ilbawi A et al. Health and cancer risks associated with low levels of alcohol consumption. Lancet Public Health. 2023;8(1):e6-e7. PMID 36603913, DOI
7. Quddos F, Fowler M, de Lima Bovo AC et al. A preliminary study of the physiological and perceptual effects of GLP-1 receptor agonists during alcohol consumption in people with obesity. Sci Rep. 2025;15(1):32385. PMID 41093891, DOI
8. Petrov MS, Yadav D. Global epidemiology and holistic prevention of pancreatitis. Nat Rev Gastroenterol Hepatol. 2019;16(3):175-184. PMID 30482911, DOI
9. Polskie Towarzystwo Leczenia Otyłości (Polish Society for the Treatment of Obesity). Zalecenia kliniczne dotyczące postępowania u chorych na otyłość 2024 (Clinical guidelines for the management of patients with obesity). Medycyna Praktyczna, special edition, September 2024. ptlo.org.pl
10. Day E, Daly C. Clinical management of the alcohol withdrawal syndrome. Addiction. 2022;117(3):804-814. PMID 34288186, DOI
11. Hendershot CS, Bremmer MP, Paladino MB et al. Once-Weekly Semaglutide in Adults With Alcohol Use Disorder: A Randomized Clinical Trial. JAMA Psychiatry. 2025;82(4):395-405. PMID 39937469, DOI