Metformin and Alcohol. Can I drink on metformin?

Metformin, Alcohol, and Diabetes

Today we want to talk about metformin and alcohol for patients with diabetes. Are you a diabetic taking metformin and drinking alcohol occasionally or heavily? If so, this article will be very important for you to read till to the end.  As an endocrinologist/diabetes doctor, I deal with patients with diabetes every day. And, I get these questions about diabetes, alcohol, and metformin all the time.

Research showed us that diabetes control requires patient adherence. That is important in order to achieve success with diabetes. There are important behaviors that every diabetic patient taking metformin or not should follow.  These are blood glucose monitoring, diabetic diet, and exercise for diabetes.  In addition to all that, avoiding alcohol generally for diabetes is a wise idea while taking metformin. But should you avoid alcohol totally? Or should you just limit the intake?

Unfortunately, adherence to diet for diabetes and alcohol recommendations is not always easy.  Social alcohol drinking is very common for patients with diabetes taking metformin. Are you a patient who drinks alcohol and taking metformin for your diabetic condition? Then, continue to read this article to have more in-depth knowledge.  You can definitely discuss this with your diabetes doctor/endocrinologist at every visit.

How Does Drink alcohol while on metformin affect me?

As diabetes doctors treating diabetes on a daily basis we know that there is a direct correlation between alcohol intake, poor diabetes control/and high HbA1c levels.

Most diabetic patients who consume alcohol frequently actually have less food consumption.  Those patients who drink alcohol while taking metformin also may not adhere to dietary and medication recommendations.  This could be due to alcohol’s effects on judgment.  Drinking alcohol can take you away from exercise and glucose self-monitoring.  Also, alcohol can cause low blood sugars.  As a result, most patients are hesitant to take their medications including insulin.  Even if they knew taking alcohol, metformin and insulin can cause low blood sugars.

This problem with adherence does not only happen to heavy drinkers but even moderate drinkers can show similar problems in terms of adhering to taking their metformin and other drugs.  Lactic acidosis is another complication in diabetic patients taking metformin and drinking alcohol.  We will examine the low blood sugar and lactic acidosis as a complication of metformin and alcohol more in detail below.

The Direct Effects of Alcohol Use on Patients Taking Metformin for Diabetes

Very small amounts of alcohol such as a glass of wine may not have an immediate effect on blood sugars.  On the other hand, if you are a diabetic patient taking insulin in addition to metformin risk is higher. Moderate to heavy alcohol consumption can increase the risk of low blood sugars. Low blood sugars can happen even after 24 hours of alcohol intake.

If you are taking metformin and sulfonylurea such as glipizide, glimepiride, and glyburide, the risk of low blood sugars with alcohol dramatically increases.  Another reason to limit alcohol is that taking metformin and alcohol together can lead to lactic acidosis.

What Are the Symptoms of Low Blood Sugar/Hypoglycemia With Metformin and Alcohol?

Symptoms of low blood sugar/hypoglycemia while taking metformin and alcohol include:

  • Shaking, mostly in the hands
  • Sweating and or hot flashes
  • Elevated heart rate
  • Feeling extremely hungry
  • Feeling dizzy or irritable
  • Confusion
  • Lack of responsiveness and coma if hypoglycemia/low blood sugar is severe enough

What Should I Do if I Have Low Blood Sugar and Take Metformin and Alcohol?

If you have low blood sugar symptoms check your blood sugar first.  If you confirm that the blood sugars are below 70 eat or drink 15 to 20 g of carbohydrates.  Recheck blood sugars in 15 to 20 minutes to ensure that your blood sugars are 15 to 20 mg/dL higher.  If you are not going to eat very soon have another 15 to 20 g of carbohydrate snack in the next 30 minutes.  Continue to monitor your blood sugars.

Can I Use Dexcom G6 or Freestyle Libre When I Have Low Blood Sugar?

Do not rely on Dexcom G6 or freestyle libre readings when you have low blood sugar.  Both Dexcom G6 and freestyle libre or guardian Medtronic are continuous glucose monitoring systems.  They are not accurate and they have delayed indicators of recovery from low blood sugars.  If you are on metformin for diabetes and drinking alcohol having a carby snack or having cocktails instead of drinking alcohol on rocks or as shots can help.  More importantly, make sure your diabetes doctor/endocrinologist knows about your alcohol habit.  Your diabetes doctor may adjust your medications accordingly.

How Does Lactic Acidosis Develop in Diabetic Patients Taking Metformin and Alcohol?

There are a variety of medications that can increase lactic acid levels.  The more medications you are on the higher the risk of elevated lactic acid levels.  Alcohol is practically a drug.  Since both alcohol and metformin can increase the chances of lactic acidosis, your risk of lactic acidosis significantly goes up.  Especially in patients who have chronic kidney disease the risk is even higher.

Medications that increase lactic acidosis are listed below.

Medications and toxins that cause lactic acidosis:

  • Alcohols
  • Metformin
  • Acetaminophen/tylenol
  • Beta-adrenergic agonists
  • Cocaine
  • Cyanogens
  • Halothane
  • Propofol
  • Isoniazid
  • Salicylates( aspirin)
  • Sulfasalazine
  • Valproic acid

What Are the Symptoms of Lactic Acidosis in Patients Taking Metformin or Alcohol?

If you are on metformin and drank alcohol and, you have diabetes watch out for the following symptoms.  This is more important if you have had a moderate to heavy alcohol consumption.

  • Abdominal pain
  • Excessive tiredness
  • Rapid heart rate
  • Confusion and changes in mental status
  • Nausea with or without vomiting
  • Fast breathing
  • Shortness of breath

I Drink Alcohol Should I Stop Taking Metformin for My Diabetes?

Stopping metformin without discussing with your diabetes doctor may not be a wise idea.  Reducing alcohol intake or totally quitting alcohol is a better idea.  That is true not only for metformin but also for other diabetic medications. For example, insulin, sulfonylurea medications like glipizide or glyburide, and glimepiride can increase the risk of severe low blood sugars.  Yet, there are certain groups of patients for whom metformin may be a high-risk medication.  This is due to the increased risk of lactic acidosis in certain medical conditions.  If you are one of those patients, discuss it with your diabetes doctor or endocrinologist.

These medical conditions include

  • Stage 4 or 5 kidney disease
  • Type I diabetic patients
  • Patients were at risk of diabetic ketoacidosis
  • Patients with advanced liver problems such as cirrhosis.
  • Patients with advanced heart problems such as stage III or IV heart failure

What Are the Other Things and I Need To Know About Metformin?

Regardless you drink alcohol or not you need to know certain things about metformin when you take it for your diabetes.  Metformin can definitely be used for insulin resistance, prediabetes, and polycystic ovarian syndrome as well.  Regardless of the condition you take it for, the effect of alcohol and metformin on a diabetic patient can be similar.

Metformin increases the risk of lactic acidosis and low blood sugars, especially in association with alcohol.  But it also can cause significant side effects.

Other Metformin Side Effects

The most common side effect of metformin is diarrhea.  On the other hand, using extended-release metformin can dramatically reduce diarrhea.  Patients who are on metformin who have diarrhea and drink alcohol are at risk of dehydration as well.  That is because alcohol consumption reduces food and water intake. Alcohol also increases water loss via stimulating urination.  This effect of alcohol in combination with metformin and diarrhea definitely increased the risk of dehydration.

How To Stop Metformin Induced Side Effects?

To reduce diarrhea please switch to extended-release metformin or ask your diabetes doctor, or endocrinologist to do so.

Another important piece of information that can help with diarrhea and metformin is taking it with meals.  Taking metformin in the evening meal or the largest meal help reduce diarrhea. If your diarrhea is unbearable and these measures are not helping please discuss this with your diabetes doctor/endocrinologist.

There are a lot of alternative medications to metformin.  So do not think that metformin is the only option. Consider using SugarMD Super Berberine.

Contrary to the belief, metformin does not cause kidney failure by itself.  Metformin actually reduces the risk of cancers.  Metformin can help improve insulin resistance and prevents progression from prediabetes to diabetes.

Patients who drink alcohol and take metformin for prediabetes are at high risk of progression to diabetes.

Another good news about metformin’s side effect of diarrhea is that it is temporary.  Most diarrhea or side effects related to diarrhea will dissipate within a few weeks of starting the medication.  If your symptoms persist after a few weeks please discuss that with your diabetes doctor or endocrinologist.


The bottom line, metformin is a precious and invaluable diabetes drug if used correctly.

Definitely, metformin is not for everybody.  Taking metformin or other diabetic medications and drinking alcohol can increase the risk of low blood sugar, and lactic acidosis.  I hope that now you have a better understanding of metformin’s side effects. You know more about how to reduce the side effects of metformin, symptoms of low blood sugars, and symptoms of lactic acidosis.  So, continue to regularly check your blood sugar.  Follow a diabetic diet.  Engage in routine physical exercise.  And, limit your alcohol intake while taking metformin. So you may easily prevent the progression of diabetes with these measures.

super berberine
Super berberine

So, if you or one of your loved ones are taking metformin for diabetes and have an alcohol problem please contact us.  We may be able to help to manage diabetes in those situations. Consider using SugarMD Super Berberine which can potentially replace metformin if you have tolerance issues but also can add to glycemic control in addition to metformin.

About the author: Dr. Ahmet Ergin is the author of The Ultimate Diabetes Book and the Founder of the SugarMD youtube channel. He practices in Port Saint Lucie, FL as an endocrinologist physician.

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