When Is the Best Time of Day to Take Metformin?

Craig Primack MD

Reviewed by Craig Primack, MD, FACP, FAAP, FOMA

Written by Shannon Ullman

Published 10/26/2023

We get it — no one enjoys taking medications. It’s just another thing to tackle on your neverending to-do list. 

If you’ve been prescribed metformin, it may be because you have prediabetes, type 2 diabetes, gestational diabetes, weight gain issues caused by antipsychotic medication or polycystic ovary syndrome (PCOS).

Also sold under the brand names Glucophage®, Fortamet®, Riomet® and Glumetza®, it’s one of the most common drugs prescribed to people with type 2 diabetes. But metformin isn’t without its side effects.

Though the side effects can be a bummer, a key strategy for mitigating them is timing. In other words, taking metformin at the right time of day can help curb unwanted effects.

Wondering what the best time of day to take metformin is to reduce side effects? It really depends.

Kind of an annoying answer, right? Don’t worry — we’ll cover how to determine when to take metformin, the best way to avoid side effects and how to stick with a schedule. Let’s get into it.

It’s super important to follow your healthcare provider’s instructions on how to take your version of metformin. The rule of thumb is to start low and adjust slowly.

Everyone’s reactions to the medication are different, so there’s no fixed dose for people with diabetes. 

How do you decide when to take metformin each day? First, you’ll need to know which type of metformin you’re prescribed and what your daily dosage is.

Dosages vary, as metformin treatment is based on the effectiveness of the medication and your tolerance — how much metformin your body can handle without side effects.

Metformin medication comes in immediate-release tablets, extended-release tablets and liquid form. Each has different requirements in terms of when and how to take it: 

  • Regular metformin tablets are taken with meals two or three times a day.

  • The extended-release metformin tablet is typically taken once a day with your evening meal.

  • Liquid metformin is typically taken with meals once or twice a day.

Here are the recommended methods for your starting dose:

  • Take 500 milligrams (mg) orally once a day or 850 milligrams once a day with meals. 

  • Increase the dose in increments of 500 milligrams weekly or 850 milligrams every one to two weeks, up to a maximum dose of 2,550 milligrams per day, taken in divided doses.

  • Doses above 2,000 milligrams may be better tolerated when given three times a day with meals.

The gist is always to take your metformin with food and aim to take your medications at the same time each day to keep yourself on a routine. Avoid taking it on an empty stomach, as you might end up with an upset stomach. 

As always, if you ever have questions about your prescription, please let your healthcare provider know. Never make assumptions about a medication, especially a new one. Remember, you didn’t go to that appointment and pay the copay for nothing.

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All medications come with an instruction manual and FDA disclaimers, but who’s reading those? If you accidentally tossed your information packet in the trash, it’s okay — we’ll guide you through taking metformin.

As mentioned above, you should always take your metformin medication with food. Doing this can help limit stomach or bowel problems, commonly occurring within the first few weeks of treatment.

Depending on your health, your healthcare provider may provide a personalized diet plan to help you manage diabetes.

Here are the dos and don’ts for taking metformin tablets:

  1. Don’t chew or crush the tablets. Unless instructed by a healthcare professional, don’t chew or crush your tablets, as this can release all the medicine at once, thus increasing your risk of gastrointestinal side effects.

  2. Don’t split the tablet. Unless your healthcare provider tells you to do so, don’t split the tablet.

  3. Do swallow the whole tablet. Drink plenty of fluids, preferably water, to wash down the tablet.

  4. Do take your medication at the same time each day. Make it a habit to take your metformin medicine at the same time each day.

Here are the steps for taking the liquid form of metformin:

  1. Measure the liquid. You can use a marked measuring spoon, a medicine cup or an oral syringe. Avoid using a teaspoon from your kitchen, as it may not hold the proper amount of liquid.

  2. Use your dosing cup. You’ll need this to measure the mixed extended-release oral suspension.

Understanding Metformin Side Effects

As noted, timing your metformin dosage is crucial for mitigating the risk — and overall severity — of side effects. But what are those side effects, exactly?

For metformin, the most common side effects are diarrhea, nausea and upset stomach.

In rare instances, metformin may lead to low blood sugar (hypoglycemia). This may happen if you’re not eating enough food, are drinking alcohol or are taking other medications to lower blood sugar.

A more severe but uncommon side effect of taking metformin is lactic acidosis. The condition occurs when there’s a buildup of lactic acid in the bloodstream. Lactic acid is produced when your oxygen levels become low in areas of the body where metabolism occurs or in response to sympathetic overactivity.

Metformin is one of many medications that can cause lactic acidosis. Symptoms of lactic acidosis include nausea, vomiting and weakness. Fortunately, the risk of lactic acidosis is a rare side effect of metformin.

If you experience serious side effects, seek medical advice immediately. Things can worsen quickly if you don’t get medical help.

If you have any questions or concerns about taking metformin, reach out to your healthcare provider.

Now that you know a bit more about metformin dosing, side effects and the recommendations for taking it, we’ve got a few tips for you.

As mentioned, the best time to take metformin really depends on your unique needs and how you react to the medication. The one constant here is that you should take it with food and water. So, working backward, the best time to take metformin is based on when you eat.

Here are some tips and considerations to keep in mind:

  • If you’re not a breakfast person, taking metformin in the morning might not be a great option. Think about what time you typically have your first meal and take your pill after that.

  • Alternatively, if you usually skip lunch or eat light dinners, taking metformin in the morning after breakfast could work best.

  • Stomach and bowel issues can be metformin side effects, especially when you’re first starting out. If you work from home and are close to a bathroom, you may be fine taking your meds at any time. However, if you have a long morning commute or work at an office, you might want to take metformin at night when you’re home, at least for the first month or so.

  • If you’re struggling to remember to take your meds, try stacking this habit onto another one. For example, leave your pills next to something you use or do each day, like your toothbrush or coffee maker. Do you feed your pet at the same time every day? Take your metformin at that time, too.

It’s not the end of the world if you forget to take your daily metformin dose. Just don’t make it a habit, okay?

If you miss one dose of metformin, try to take it as soon as you remember. But if it’s close to the time of your next dose, just skip the missed dose and continue taking it according to your normal schedule. You should never take two doses at the same time to make up for a forgotten dose.

Keep in mind, the purpose of taking metformin is to regulate your blood glucose levels. So if you miss too many doses, hyperglycemia (high blood glucose levels) may occur.

If it’s difficult to remember when to take metformin, set an alarm to remind yourself. You can also ask your healthcare provider for tips on remembering to take your medication. 

As easy as it can be to forget a dose of metformin here and there, there’s a maximum daily dose, so it’s possible to take too much metformin. 

Metformin overdose can include hypoglycemia and the following symptoms:

  • Abnormally fast or slow heartbeat

  • Decreased appetite

  • Deep, rapid breathing

  • Dizziness

  • General discomfort

  • Extreme tiredness

  • Feeling cold

  • Flushing of the skin

  • Vomiting

  • Nausea

  • Stomach pain

  • Lightheadedness

  • Muscle pain

  • Shortness of breath

  • Weakness

If you’re experiencing these symptoms, please contact the poison control helpline at 1-800-222-1222 or call emergency services. 

Life gets busy, and it can be easy to forget to take your prescription drugs. Remembering all the instructions on dosage and timing can be another hurdle.

Still, it’s crucial to understand what you’re taking so you don’t have to deal with those nasty side effects. Here’s a quick recap:

  • Metformin is a first-line medication for type 2 diabetes. People with type 2 diabetes take metformin to help control high blood sugar levels. Diabetes can cause many health issues, including sexual health challenges like erectile dysfunction (ED). Besides type 2 diabetes management, metformin has been shown to help non-diabetic people lose weight. The medication isn’t prescribed for type 1 diabetes.

  • The best time to take metformin depends on the medication type and dosage. Some people take metformin once, twice or even three times a day, depending on the type of metformin (tablet or liquid) and how many milligrams they’re prescribed.

  • Always take metformin with food and water. It’s recommended to take metformin after eating food and wash it down with fluids, such as water. 

  • Don’t alter the tablets. Unless instructed by a healthcare professional, never crush, chew or split the tablets, as this can alter the effectiveness of the medicine in your body. You’ll want to store them at room temperature too.

  • Prepare for potential side effects. Taking metformin may cause unpleasant side effects like diarrhea, nausea, upset stomach and, in rare cases, lactic acidosis. 

  • Don’t double up on metformin if you miss a dose. Instead, just skip the missed dose and take the next dose at your regular time.

Interested in learning more about how certain medical conditions and medications cause weight loss? Here’s a look at the connection between weight loss and depression and whether antidepressants lead to weight loss

If you’re looking to learn more about weight loss treatments, our telehealth services can connect you with a licensed healthcare provider who can answer your questions and offer medical guidance.

13 Sources

Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references.

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This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.