Mixing alcohol and metformin may not be the best idea. Read about alcohol and metformin side effects and interactions on this page.

If you have prediabetes or diabetes and are taking metformin to help control your blood sugar, you may be wondering if it is safe to drink alcohol. It is much better to avoid alcohol if you have diabetes, especially if you are taking metformin. However, there are important considerations you should be aware of so that you can drink alcohol safely if you choose to drink.

Article at a Glance:

In summary, there are several important points to remember about alcohol and metformin use.

  • It is best not to drink alcohol if you have diabetes, and especially if you are taking metformin
  • It is common to get low blood sugar when you drink alcohol if you have diabetes
  • It can be hard to realize you have low blood sugar because those symptoms are similar to the symptoms of being drunk
  • Although there are ways to be safer when drinking alcohol while having diabetes, the possible risk for lactic acidosis with alcohol and metformin use is serious enough for the FDA to have made a Black Box Warning about it
  • Avoiding alcohol if you have diabetes and are taking metformin is the safest option

Alcohol and Metformin Side Effects

Metformin is one of the top drugs recommended to treat diabetes by the American Diabetes Association. Many studies have shown its ability to control blood sugar and save lives. However, metformin on its own often causes issues including stomach upset and diarrhea. If you drink alcohol, you may increase your risk of these side effects. If you already have these side effects from metformin, drinking alcohol can make them worse.

When you have diabetes, drinking alcohol can be risky. Drinking alcohol can lower your blood sugar levels and cause hypoglycemia. The reason why this effect can happen is that normally your liver makes an “emergency stash” of sugar. This store helps you avoid low blood sugar. If your blood sugar gets too low, your liver can dip into the emergency stash of sugar. The liver then uses that sugar to bring your blood sugar up again.

However, alcohol interferes with this process. Alcohol stops the liver from being able to make that emergency stash. Therefore, if your blood sugar starts to get low, your liver is not able to correct the issue as easily if you have been drinking alcohol. This effect can last up to 24 hours after you have had alcohol.

Making matters even more dangerous, the symptoms of low blood sugar can be very similar to symptoms of alcohol use. These symptoms may include:

  • Dizziness
  • Confusion
  • Drowsiness

It can, therefore, be very easy to think you are just feeling a buzz from alcohol, when in fact you have low blood sugar.

Additionally, if you already have liver disease, your liver may not be working properly as it is, and the addition of alcohol can compound the problem. If you regularly drink alcohol, it is important to know that you already face an increased risk of getting liver disease. However, it is possible to repair your liver after long-term alcohol use.

Metformin and Alcohol Can Cause Lactic Acidosis

There is also a possible severe interaction between metformin and alcohol. This interaction can lead to a condition called lactic acidosis. Lactic acidosis occurs when the blood turns acidic and there is a build-up of a chemical called lactate in your body. Metformin alone can lead to lactate buildup in your body, and alcohol has been shown to have this effect as well.

Therefore, the combination of alcohol and metformin together may be even more dangerous than either one alone. The Food and Drug Administration (FDA) issued a Black Box Warning on metformin to look out for symptoms and risk factors for lactic acidosis, and excessive alcohol use is one of the risk factors.

The U.S. government defines excessive alcohol use as more than one drink a day for a woman and more than two drinks a day for a man. If you choose to drink alcohol while being on metformin, it is essential to drink less than what is defined as excessive alcohol use.

Managing Diabetes While Drinking Alcohol

Fortunately, the American Diabetes Association has advice for people with diabetes who would like to drink alcohol more safely. Although they do not have specific recommendations for drinking alcohol while on metformin, they have helpful tips for how to more safely manage your diabetes when you are drinking alcohol:

Related Topic: Does alcohol raise blood sugar

If you or a loved one struggle with alcohol addiction, trained professionals at The Recovery Village can help you overcome alcohol abuse and addiction. The Recovery Village offers many different addiction treatment options to help you lead a healthier life. Reach out to us today for more information.

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Editor – Camille Renzoni
Cami Renzoni is a creative writer and editor for The Recovery Village. As an advocate for behavioral health, Cami is certified in mental health first aid and encourages people who face substance use disorders to ask for the help they deserve. Read more
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Medically Reviewed By – Dr. Jessica Pyhtila, PharmD
Dr. Jessica Pyhtila is a Clinical Pharmacy Specialist based in Baltimore, Maryland with practice sites in inpatient palliative care and outpatient primary care at the Department of Veteran Affairs. Read more

American Diabetes Association. “Alcohol.” Updated October 16, 2017. Accessed March 22, 2019.

U.S. National Library of Medicine. “Metformin.” Updated February 7, 2017. Accessed March 22, 2019.

American Diabetes Association. “Standards of Medical Care in Diabetes 2019.” Updated January 2019. Accessed March 22, 2019.

Medical Disclaimer

The Recovery Village aims to improve the quality of life for people struggling with substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare providers.