The Independent Pharmacy

Metronidazole And Alcohol: Side Effects & Safety Concerns

Scott McDougall
Scott McDougallMPharmDirector & Registered Manager

Reviewed on 30 Nov 2023

Bacterial Vaginosis (also known as BV) is a common vaginal infection where the normal balance of bacteria in the vagina becomes disrupted — but it can feel embarrassing and awkward to seek treatment. Luckily, it is now very easy to buy effective treatments like Metronidazole online.

However, if you do, there are a few things that you need to know — such as if you are able to combine Metronidazole and alcohol.

In this post, we’ll be answering any queries you have about drinking alcohol while taking Metronidazole — such as whether it is safe to do so, and if there are any negative side effects you could experience. Read on to find out more.

For a more general guide on Metronidazole, you can visit our ‘What is Metronidazole?’ page.

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Metronidazole 400mg Tablets
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Can you drink alcohol on Metronidazole?

You can't drink alcohol on Metronidazole as the interaction produces side effects such as vomiting, flushing, or a racing heart. For safety, avoid alcohol for 2 days after you finish taking Metronidazole. Even a small amount of alcohol in a mouthwash can cause issues.

The negative impact of mixing Metronidazole and alcohol is significant and has been shown to produce side effects even with very small amounts of alcohol. Because of this, it isn’t enough to limit yourself to one drink or choose something with low alcohol content. Cough syrup with alcohol as an ingredient could lead to a bad reaction.

It isn’t clear why mixing Metronidazole with alcohol produces such major side effects, as there hasn’t been much research into this topic. Even so, the impact is undeniable.

Mixing Metronidazole and alcohol: side effects & safety concerns

It’s important to be aware of the interaction between Metronidazole and alcohol and know the possible reactions you may have if you drink while using the popular BV treatment.

Mixing Metronidazole and alcohol can cause an array of unwanted — and sometimes very severe — side effects. This is on top of the common side effects that people may experience when taking Metronidazole. You can find out more about Metronidazole side effects here.

These are the common side effects of drinking on Metronidazole:

  • Nausea
  • Vomiting
  • Stomach pains
  • Cramping
  • Fast and/or irregular heartbeat (known as heart palpitations)
  • Throbbing in the head and neck
  • Headaches
  • Dizziness or lightheadedness
  • Flushing (warmth and redness, particularly in the face)

These unpleasant side effects can last from anywhere between 30 minutes to several hours, depending on the individual as well as the amount of alcohol consumed.

In rare circumstances, mixing Metronidazole and alcohol can also cause more severe reactions. These can include a potentially dangerous rapid heart rate, sudden drop in blood pressure, and even liver damage.

Drinking on Metronidazole may also cause seizures, so if you have a history of seizures you should be especially careful about mixing the two, and seek advice from your doctor.

What you should do about the Metronidazole alcohol interaction?

In most cases, any bad reactions you have from a Metronidazole alcohol interaction should be over in between 30 minutes to several hours. Of course, this will vary between each individual situation, depending on how much alcohol you have consumed and how your body naturally reacts.

If you have consumed alcohol with Metronidazole, there are a few things you should do.

Firstly, do not drink any more alcohol. Sip on water instead — this should help to ease feelings of nausea. You should also sit down and avoid any sudden movements to help with any lightheadedness you have from flushing, headaches and increased heart rate.

If your symptoms persist or become worse, you should seek medical help. In the UK, you can contact your GP or call 111.

When is it safe to drink alcohol after using Metronidazole?

It is recommended by both medical professionals and manufacturers of Metronidazole that you avoid drinking alcohol while taking it, and for 48 hours (two days) after finishing the course of treatment.

This is the rough amount of time that it takes for Metronidazole to be cleared from your system. This timeframe is given for the average adult body, so it may vary; if you want to be really sure, you can leave it for three days before you start drinking alcohol again.

Once this period has passed, you can go back to drinking alcohol and using products that contain alcohol (like mouthwash) as you did before.

How to use Metronidazole to treat BV safely

It is very easy to use Metronidazole safely. Simply take the medication exactly as prescribed by your doctor. Your instructions will usually be to take one 400g tablet twice daily for seven days.

You may start to see improvements to your condition before your course has ended, but you should always make sure that you complete your course of treatment, even if you think your symptoms have disappeared. This will help to prevent the infection from coming back.

Do not take this medicine in larger or smaller doses than your doctor or the directions on your prescription label suggest. You should also avoid taking Metronidazole for longer than recommended.

Metronidazole tablets can be taken with or without food. However, as nausea can be a common side effect of taking the medication, it is generally recommended that you take the tablets on a full stomach — so should be taken with or after food.

It is generally not advisable to use Metronidazole to treat BV if you are pregnant so it’s a good idea to speak to your doctor first before starting treatment. As BV is not harmful to the baby, it is usually not considered to be worth the risk to treat BV using Metronidazole tablets whilst pregnant. You can find out more about Metronidazole and pregnancy here.


Metronidazole is a safe and effective medication used to treat bacterial vaginosis (BV) and other vaginal infections.

It is strongly recommended that you do not mix Metronidazole and alcohol. Drinking on Metronidazole is known to cause bad reactions, and may result in a number of unpleasant side effects. When starting any course of treatment, it is best to follow the prescription label directions to take it as safely as possible.

You can buy Metronidazole at The Independent Pharmacy; we offer a fast, secure and discreet online service and delivery straight to your door.

For more information on bacterial vaginosis, you can visit our BV treatment page.


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