For many people with prediabetes or type 2 diabetes, taking metformin is an important first step for improving blood sugar levels and health. 

However, when you take metformin can be almost as important as whether you take metformin at all. 

This article will explain everything you need to know about the best time to take metformin.

Man looking at watch to decide when to take metformin

Key Points:

  • It’s essential to take metformin at the same time each day for maximum effectiveness. While the exact timing can vary based on individual needs, keeping a regular schedule helps ensure the drug works properly and you get the best/maximum results from the medication.
  • Taking metformin with or after meals can help reduce potential side effects such as nausea and upset stomach. Many people find it beneficial to take their dose with their evening meal, allowing the medication to work overnight.
  • If you are also using insulin, avoid taking metformin immediately before exercise to reduce the risk of low blood sugar. 
  • While metformin can be taken on an empty stomach, doing so may cause nausea, especially if only accompanied by coffee or during fasting periods.

How is metformin taken? 

Metformin comes in tablet form and is taken orally. There are two different types of tablets: standard and slow-release metformin (also known as extended-release, or ER or XR). 

There are pros and cons to the different types of metformin. Your doctor will recommend which version they think is best for you and advise you on how to take it and how often to take it. 

Standard metformin pills release the medication into your body more quickly and may require several doses per day. 

Extended-release metformin is released slowly into your body and does not need to be taken as often. The potential side effects may be less severe as a result — especially gastrointestinal side effects such as bloating, constipation, or diarrhea.

Learn more in: Can Metformin Cause Diarrhea?

Metformin tablets are swallowed whole and usually taken with water. Do not crush or chew metformin tablets. 

Liquid metformin is available for children and people who have trouble swallowing. 

What is the standard dose of metformin? 

Metformin comes in different doses, including 500 milligrams (mg), 850 mg, and 1,000 mg for immediate release and 500 mg, 750 mg, and 1,000 mg for extended release. The maximum daily dose of metformin is 2,550 mg. 

Liquid metformin is taken in 5-milliliter (ml) doses of 500 mg, 850 mg, or 1,000 mg. 

Your doctor will most likely start you on a smaller dose of metformin to begin with, and then ratchet up your dose over time if you’re seeing good results in blood sugar levels without too serious side effects.

Do not increase your metformin dose without the guidance of your doctor. If you start to experience negative side effects after your dose has been increased, let your doctor know. They may decrease your dose or switch you to extended-release tablets to help mitigate those side effects. 

Never take more metformin than your doctor has prescribed to you. If you do, you can experience severe side effects, such as uncontrollable vomiting, nausea, diarrhea, stomachache, or dangerously low blood sugar levels (hypoglycemia)

Contact your doctor immediately or call 911 if you’ve taken more metformin than prescribed or if you’ve accidentally overdosed. 

See more in: Metformin Dosage Guide (Min and Max Doses).

When is the best time to take metformin? 

Some times of day are better for taking metformin than others. These hints may help you settle on a good schedule for how to take metformin (but be sure to work with your doctor to figure out when is the best time for you to take your medicine).

Lean into consistency

First and foremost, the most ideal time to take metformin is at a time each day that you are most likely to remember to take it. 

The key to taking metformin — or any prescription drug — is consistency because if you cannot routinely remember to take your medications, they will not be helpful. So, it’s best to take your metformin at the same time every day. 

And remember, what works for you may not work for someone else, so make sure that when and how you take your metformin is based on what works best for you and your personal needs. 

Know that taking metformin with or after a meal can curb side effects 

Metformin can be taken with or without food. However, if you’re prone to its side effects, such as nausea, upset stomach, diarrhea, or vomiting, it is best to take metformin with or after a meal. 

This will make it less likely that you’ll experience side effects and it will make metformin easier to digest. 

Many people take their daily metformin with or after their evening meal, letting the medication work all night long to lower blood sugar levels without the side effects. 

Read more in: Signs Metformin Is Working (Or Isn’t Working).

Do not take metformin before exercise if you are on insulin

If you’re on insulin, taking metformin right before you exercise can increase the likelihood of experiencing low blood sugar, which can be particularly dangerous. Symptoms of low blood sugar during exercise include dizziness, confusion, and fatigue, which may impair your ability to safely complete your workout. 

Additionally, low blood sugar can slow wound healing and increase the risk of injuries. To help prevent these issues, it’s recommended to take metformin several hours before or after you’ve finished exercising.

Be wary of taking metformin on an empty stomach 

Taking all of your medications first thing in the morning may be the easiest way to remember to take them daily. However, if you take metformin on an empty stomach (or only with coffee), it may cause nausea that can persist throughout the day. 

To avoid this, consider taking metformin after a light morning snack, such as a piece of toast or a small bowl of oatmeal. This can help mitigate nausea without requiring a full, robust breakfast.

However, if you’re fasting for blood work, a procedure, or doing intermittent fasting (IF), metformin is safe to take on an empty stomach. 

Frequently asked questions

What if I forget to take a dose of metformin?

If you forget to take your daily dose of metformin, skip your missed dose and simply take your next one at your regularly scheduled time.

Never take two doses as a way to make up for a lost dose. Missing one dose will not harm you or increase your blood sugar levels. 

I’ve taken too much metformin; what do I do? 

Metformin is generally safe, but taking too much metformin can cause negative side effects like extreme nausea, vomiting, stomachache, dangerously low blood sugar levels, feeling cold, shallow breathing, sleepiness, weakness, and fatigue.

Call your doctor or 911 if you’ve taken too much metformin and are experiencing any of these symptoms. 

Learn more in: Is Metformin Safe?

How long do I have to take metformin? 

There is currently no cure for diabetes, and treatment is usually for life. However, if you’re not seeing results or are experiencing negative side effects, it may be time to talk with your doctor. 

Read more in: Metformin Side Effects (Common and Serious).

They may recommend that you either decrease your dose or find an alternative to metformin, or they may take you off the medication completely.

Know that it can take several weeks to months to start seeing results from metformin, depending on what your health goals are. Never stop taking any diabetes medications without proper guidance from your doctor first. 

See more in: Stopping Metformin: When and How You Can Stop Taking Metformin.

Is it better to take metformin in the morning or at night? 

Metformin is best taken with a meal, so whether that’s a morning or evening meal is up to you. However, many people with diabetes experience the dawn phenomenon, or an early-morning rise in blood sugar.

So, what is the benefit of taking metformin at night? Taking your metformin with an evening meal can help alleviate the next day’s morning high blood sugar levels, whereas if you take it in the morning, you may be dealing with higher blood sugar when you wake up. 

Recent studies, including research from 2023, show that the time you take metformin can affect how well it works and how it makes you feel. These studies suggest that taking metformin at the right time, based on your body’s natural rhythms, can help it work better and reduce side effects.

What do I do if I take metformin twice per day? 

You can take your first dose in the morning with breakfast, and your second dose in the evening with dinner. 

How do I store metformin? 

It is best to keep metformin locked away from children, in a sealed container at room temperature

Do not put metformin in the freezer, and keep it away from heat, light, and moisture.

Always check expiration dates, and do not take expired medicine. Talk with your doctor about disposing of any old or expired medications that you can no longer use. 

Suggested next article: Everything You Need to Know About Metformin.