Metformin and Alcohol: Can You Mix Them?

Key Takeaways

• You may be able to drink moderate amounts of alcohol while taking metformin, especially if your blood sugar is stable, but always consult your doctor first.
• Heavy or binge drinking while on metformin can be dangerous. It increases the risk of hypoglycemia (low blood sugar) and lactic acidosis, a rare but life-threatening condition.
• People over 65, those with kidney or liver problems, or anyone taking insulin may be at higher risk of side effects from drinking while taking metformin. </InfoPanel>

The type 2 diabetes drugmetformin (Glucophage) is one of the most commonly prescribed medications in the US, taken by an estimated 24 million Americans.

Metformin is taken daily, so it’s normal to have questions about its effect on your day-to-day routine. And since some people prefer to have a glass of wine or beer from time to time, you may be wondering if it’s safe to have an alcoholic beverage while on the medication.

However, when it comes to combining alcohol and metformin, there are some important safety considerations to keep in mind. Read on to learn how metformin and alcohol interact, if it’s safe to mix them, and other risks and side effects of drinking while taking metformin.

Can I drink alcohol while taking metformin?

Generally, it’s ok to drink in moderate amounts while taking metformin if your diabetes is under control and your healthcare provider has confirmed it’s safe for you. Moderate drinking is defined as one drink per day for women, and no more than two drinks per day for men.

One standard drink equals:

• 12 oz of beer OR
• 8 oz of malt liquor OR
• 5 oz of wine OR
• 1.5 oz of distilled spirits (such as vodka or whiskey)

However, heavy drinking or binge drinking while taking metformin can increase your risk of serious side effects, including low blood sugar and stomach issues.

Heavy drinking is defined as:

• Eight or more drinks per week for women
• Fifteen or more drinks per week for men

Binge drinking is defined as:

• Four or more drinks on a single occasion for women
• Five or more drinks on a single occasion for men

If you have type 2 diabetes and plan on having a drink while using metformin, keep these tips in mind:

• Never drink on an empty stomach
• Drink water before and after your drink to avoid dehydration
• Avoid heavy or binge drinking and stick to recommended serving sizes
• Stay away from sugary mixers and cocktails when possible
• Check your blood sugar levels before drinking, before bed, and for up to 24 hours after drinking

Even if your blood sugar levels are stable, it’s still important to talk to your doctor before drinking alcohol while taking metformin. Your healthcare provider knows your full medical history and can offer personalized guidance based on your specific health needs.

Who is at higher risk when combining alcohol and metformin?

While moderate drinking may be safe for some, certain people face a greater risk of health complications when combining alcohol with metformin.

Groups at higher risk for complications include:

• People with liver or kidney problems. Alcohol and metformin can put extra stress on these organs and raise the risk of serious health problems.
• People taking insulin or other diabetes medications. Alcohol can cause blood sugar to drop too low (hypoglycemia) when mixed with these drugs.
• Women. Alcohol often affects women more than men, which can increase the chance of side effects.
• Older adults. As the body ages, it processes alcohol differently. This raises the risk of low blood sugar or dizziness.

If you’re in one of these groups, it’s especially important to check with your doctor before drinking alcohol while on metformin.

How metformin works

Metformin works by keeping your body’s blood sugar (glucose) at a healthy level. Healthy blood sugar levels are incredibly important for people with type 2 diabetes (as well as conditions like prediabetes and polycystic ovary syndrome (PCOS), since blood sugar levels are often too high in people with these conditions.

This is because their body is resistant to insulin, a natural hormone that helps move sugar from your blood into your cells. And if you have insulin resistance, sugar builds up in your blood instead of entering your cells to be used for energy. Metformin helps to bring high blood sugar back down to a healthy level.

How metformin lowers blood sugar

Metformin helps lower blood sugar levels in two ways:

1. It signals your liver to slow down its sugar production.
2. It makes your cells more sensitive to insulin, so they can process sugar more effectively.

These actions make it easier for your body to move sugar out of your blood and into your cells.

By keeping your blood sugar steady, metformin helps lower the chance of long-term problems from diabetes, like nerve and blood vessel damage.

Risks of excessive drinking on metformin

Excessive alcohol use while taking metformin can increase your risk of several serious side effects. This includes conditions like lactic acidosis and hypoglycemia. Both of these conditions can be life-threatening and require immediate medical attention. Here’s what you need to know about these issues.

Lactic acidosis

Metformin increases your body’s lactic acid production, and alcohol slows down your liver’s ability to clear the lactic acid from your body. Together, this combination can increase your risk for lactic acidosis, a rare condition that occurs when too much lactic acid builds up in your blood.

Lactic acidosis can cause serious health problems, including low body temperature (hypothermia) and low blood pressure (hypotension). If not treated right away, the condition may even lead to organ failure.

Warning signs of lactic acidosis include:

• Muscle pain or cramps
• Extreme fatigue
• Feeling dizzy or cold
• Slow heartbeat
• Stomach pain or discomfort

If you have any of these symptoms after drinking while on metformin, get emergency medical help right away.

Hypoglycemia (low blood sugar)

Metformin lowers your blood sugar by making it harder for your liver to release glucose in your blood. Drinking can also make it hard for your liver to release glucose, since it’s working hard to process alcohol. Mixing metformin with alcohol can cause your blood sugar to become too low, a condition known as hypoglycemia.

Common signs of hypoglycemia include:

• Shaking
• Sweating
• Fast heartbeat
• Dizziness
• Hunger
• Headache
• Irritability

If you experience symptoms of low blood sugar while drinking, you should:

• Stop drinking immediately.
• Consume fast-acting sugar—such as juice, glucose tablets, candy, or nonfat milk.
• Check your blood sugar again after 15 minutes. Repeat if necessary.
• In cases of fainting or loss of consciousness, call 911 right away.

A glucagon emergency kit—available by prescription—can help quickly raise blood sugar in these situations. This fast-acting injectable hormone is designed for emergencies when the person can't eat or drink. Ask your doctor if you should carry one, especially if you take insulin or have a history of severe low blood sugar.

Additional side effects and interactions of metformin and alcohol

Lactic acidosis and hypoglycemia aren’t the only risks of mixing metformin with alcohol. Drinking can also make some of metformin’s side effects worse, like vitamin B12 deficiency and digestive problems.

Vitamin B12 deficiency

Metformin and alcohol can both lower vitamin B12 levels. Over time, this can lead to anemia and other problems.

Gastrointestinal (GI) side effects

Metformin is known to cause some gastrointestinal (GI) side effects, including nausea, vomiting, diarrhea, stomach pain, and loss of appetite. Alcohol can make these issues even worse.

Because of these risks, it’s important to talk with your doctor about your alcohol use. Most importantly, understand what counts as moderate drinking—and what may be too much.

How Sesame can help

Moderate alcohol use may be safe for some people on metformin, but it also comes with significant risks. If you have questions about mixing alcohol while taking metformin, a provider on Sesame can offer guidance.

To get started, book a same-day virtual visit with an online diabetes doctor. Your provider can help you to identify what moderate alcohol use looks like. They can also assess your risk factors and ensure that you are safely managing your type 2 diabetes.