Alcohol and GLP-1: why it may affect you differently and how to reduce the risks

Why might alcohol affect you more when taking a GLP-1?

Semaglutide (Ozempic, Wegovy) slows stomach emptying [1], and other medicines in this group, such as tirzepatide (Mounjaro), work in a similar way. Food and drink take longer to pass into the intestine.

Nausea is already one of the most common side effects of treatment [1]. When food stays in your stomach for longer, a drink may add to that discomfort and affect you more than before.

The product information warns that this slower stomach emptying may change how quickly other medicines taken by mouth are absorbed [1]. It says nothing about alcohol. There is still little evidence on how these medicines affect blood alcohol levels, so the prudent approach is to drink less and more slowly.

Is there an interaction between the medicine and alcohol?

The semaglutide product information does not report a direct interaction with alcohol [1]. Treatment changes digestion and appetite, and that is what this guide is about.

If you use insulin or medicines that can make your blood sugar too low, such as sulfonylureas, alcohol does have a known interaction. It can cause low blood sugar several hours after drinking [2]. A GLP-1 medicine combined with these medicines already increases the risk of low blood sugar [1].

With a smaller appetite and smaller meals, that risk increases. If you check your blood sugar at home, do so after drinking and before going to bed too [2]. Share this information with the person who adjusts your medication.

Why do some people find that alcohol affects them more?

When you feel less hungry, it is easy to have your usual drink with much less food than before. On an empty stomach, alcohol can affect you sooner and more strongly. What has changed is the food you have with it.

Other people find they feel less like drinking. A review of fourteen studies in people who drank alcohol in a harmful way found that semaglutide and liraglutide reduced alcohol consumption [3]. These findings are promising, but these medicines are not approved to treat alcohol consumption.

If you find it hard to stop once you start, or drink to ease anxiety, it may be helpful to discuss this separately with your doctor or a psychologist. Telling us during an appointment will not change how we treat you, and helps us support you better.

How to reduce the risks if you choose to drink

The simplest advice is never to drink on an empty stomach. Choose small amounts, preferably lower-strength drinks, and drink slowly.

In Spain, one standard drink contains 10 g of alcohol, roughly the amount in a small glass of wine or a small beer [4]. A spirit and mixer contains considerably more. No amount of alcohol is safe for your health (WHO): the less, the better; and none during pregnancy or breastfeeding, in childhood, before driving, or if your medication does not allow it [4].

Do not pour another drink until you have finished the first. If you start to feel nauseous, dizzy or unsettled, stop there, even if that amount used to feel fine.

With a GLP-1, the same drink may feel different because it reaches a stomach that is working more slowly.

A celebratory dinner, step by step

1. Eat as usual during the day and do not save room for the evening. Arriving hungry is what tends to make the biggest difference afterwards.
2. At the pre-dinner drinks, start with water or a sugar-free soft drink and order something to eat before your first alcoholic drink.
3. With dinner, have a glass of wine or a small beer, and keep water on the table.
4. After dinner, if you would like another, make it a small one. If you feel full, skip it.
5. When you get home, have a glass of water before bed.

What questions do we hear in appointments?

The most common is whether one drink will ruin the treatment. It will not. The main things that can make a difference are drinking on an empty stomach or trying to drink as much as you used to.

People also ask whether alcohol slows weight loss. It contains calories, like any sugar-sweetened drink. You do not need to cut it out for that reason; simply count it as part of your week. When your appetite is low, each drink also takes up room you need for protein, which helps you maintain muscle as you lose weight.

Another common question is whether it matters which day you have your injection. The product information does not set any restrictions on alcohol based on the day of your dose [1]. In appointments, we find that side effects tend to occur in the days after an injection and after a dose increase. These are the days when it is advisable to drink less or not at all.

What about a hangover the next day?

Hangover nausea and nausea caused by a GLP-1 can feel similar. Some people find the effects add up, and the next day can be harder than expected.

Start the morning with a small amount of something gentle, such as toast, broth or ripe fruit. Sip water regularly. If you cannot manage solid food for several hours, do not force it, but try again as soon as you can.

When it is better not to drink at all

If you have nausea, vomiting or diarrhoea, or have just increased your dose, leave alcohol for another time. Vomiting and diarrhoea can already cause dehydration [1], and alcohol makes this worse.

If you have had pancreatitis, avoid alcohol and discuss your medical history with the person who prescribes your treatment before drinking [1].