Metformin and alcohol: Can you drink if you’re taking this drug for weight loss?

Thanks to new advances in medicine, you have more than several options for weight loss and weight management. One approach to consider is a drug for type 2 diabetes, metformin—which is well suited for people who have high blood sugar. An important note to keep in mind if you're considering this medication or you've just started is that you'll need to monitor your alcohol consumption closely.

We'll look at why that's necessary, but first, it's helpful to understand how metformin works, and why metformin and alcohol, if used together, can lead to some complications.  

What is metformin?

According to the National Institutes of Health’s National Library of Medicine, metformin is in a class of drugs called biguanides, which helps control the amount of sugar in your blood (or blood glucose levels). It decreases the amount of glucose you absorb from your food and the amount made by your liver while also increasing the body's response to insulin—a hormone that regulates blood sugar levels. Because of this, metformin is often prescribed for treating type 2 diabetes.

Whether you have type 2 diabetes or not, metformin has been shown to promote weight loss as an effect of the medication. For example, a small study on weight loss in non-diabetic individuals found that those treated with metformin lost an average of about 15 pounds over six months of use, while, on average, those who didn't take metformin gained as much as 7 pounds during the same six months.

Cautions with metformin and alcohol

As with any medication, metformin use includes the risk of side effects. Found’s clinicians recommend avoiding alcohol while taking any weight loss medication—any amount of alcohol presents a risk of side effects, and that risk may increase if you regularly drink more alcohol than recommended. (As a reminder, the CDC’s guideline is one drink or less per day for women and two or less for men.) Combining metformin and alcohol may trigger two specific side effects: hypoglycemia and lactic acidosis.

• Hypoglycemia: Also known as low blood sugar, the risk of hypoglycemia increases with binge drinking or chronic drinking when you're taking metformin. Hypoglycemia can lead to an irregular heartbeat, dizziness, fatigue, blurry vision, or drowsiness, and in severe cases, may cause seizures and loss of consciousness.
  
  
• Lactic Acidosis: This buildup of lactic acid in the bloodstream is a rare but serious side effect of metformin. When you drink alcohol, it interferes with your body’s use of sugar and carbohydrates for energy, which can increase your body’s level of lactic acid, a chemical that's naturally produced to provide energy. Taking metformin blocks an enzyme used in metabolizing lactic acid, which also can increase its level. Taking metformin and drinking alcohol can cause a buildup of lactic acid, which can damage organs like the heart, lungs, and kidneys. Lactic acidosis is considered a medical emergency and must be treated immediately—it may become life-threatening. Symptoms of lactic acidosis include vomiting, nausea, drowsiness, and weakness. 

Combining alcohol and metformin may also cause a vitamin B-12 deficiency if you have type 2 diabetes and you're taking metformin to control that condition as well as lower your weight. The American Diabetes Association recommends that people with diabetes who take metformin should have their B-12 level checked as part of an annual checkup.

That's because metformin can lower B-12 levels by blocking its absorption, which may lead to deficiency-related anemia that includes symptoms like weak muscles, nausea, numbness or tingling in the hands and feet, and tiredness.

Alcohol is also problematic for vitamin B-12 absorption. Research suggests that alcohol consumption can reduce the body’s absorption of B-12, which means even if you're taking a B-12 supplement to counteract metformin's effects, excessive alcohol use may block how much of B-12 your body has available to use.  

Other metformin side effects and risks 

The most common side effects of metformin include diarrhea, nausea, vomiting, gas, bloating, and stomach cramps. These gastrointestinal side effects are usually temporary. 

The U.S. Food and Drug Administration (FDA) also has a “black box warning” on metformin because of the risk of lactic acidosis.

Additionally, metformin may stimulate ovulation in those with PCOS or who are premenopausal and may increase the risk of unintended pregnancy.  If you’re in a sexual relationship that can result in pregnancy, use at least one form of birth control. Find detailed side effect and risk information on our dedicated metformin page.  

‍

Do other drugs for weight loss have interactions with alcohol? 

If mindful drinking is a part of your lifestyle, talk to your provider about different medications for weight loss that don’t interact with alcohol the way metformin does.

Even more important for weight loss is getting a prescription that works with your biology to help you lose weight. Scientists now know that genetics and hormones play a part in how much a person weighs—and that medicine for weight loss should be personalized depending on the root cause of weight gain. 

Found-affiliated health care providers are trained in obesity medicine. They use Found’s proprietary assessment, MetabolicPrint^TM, and evaluate your lifestyle, current health conditions, and weight history to tailor a weight loss prescription for you. Your Found provider may recommend drugs that are FDA-approved for weight loss or suggest a medication prescribed off-label for weight loss. 

‍

Mindful drinking

No matter what medication you take for weight loss—or even if you're not taking one at all—the fact is that alcohol use and weight loss typically aren't a great mix.

Alcohol can sabotage your progress—and even lead to weight gain—for a number of reasons. Primarily, alcoholic drinks are high in calories, and one mixed cocktail can contain as many calories as a complete meal (but without the nutrients). Alcohol has 7 calories per gram, compared to carbs and protein, which have 4 calories per gram. (Fat has 9 calories per gram.)  

Another factor is that many people make less healthy food choices when drinking. So, not only do you consume more calories because of the alcohol, but your calorie count can climb even higher if you reach for high-calorie foods as a result.

That said, this doesn't mean you have to skip alcohol altogether. Taking a mindful approach to drinking that focuses on moderate alcohol consumption and enjoyment can go a long way toward reducing how much you consume. For example, try planning alcohol into your daily calorie count so you know in advance how much you’ll be drinking. You can also talk to your health care provider about how to safely consume alcohol while you’re on your weight loss journey. 

As you navigate through issues like these, you don't have to assess these types of medication and behavior habits on your own. Found’s health care providers are available to help you lose weight with the medication and lifestyle changes that work best for you. Found members also get support from a health coach and an in-app community. 

About Found

Found is among the largest medically-supported telehealth weight care clinics in the country, having served more than 200,000 members to date. To start your journey with Found, take our quiz.

‍