Summary
- Metformin is highly effective for type 2 diabetes but can cause diarrhea and digestive discomfort.
- Up to 53% of people who take immediate-release metformin experience gastrointestinal symptoms.
- Starting with a low dose of metformin and increasing gradually can lessen digestive side effects.
- Taking metformin with food helps reduce digestive irritation.
- Extended-release metformin is often better tolerated than the standard form.
- Dietary adjustments and proper hydration can improve tolerance.
Metformin is widely recognized as one of the most trusted and effective medications for type 2 diabetes. Despite its effectiveness, it can sometimes lead to digestive discomfort, including diarrhea. If you have dealt with this issue, you are not alone. The good news? It is common, often temporary, and usually manageable with the right approach.
In this guide, we will explain exactly why metformin can cause digestive upset, supported by scientific understanding, and what you can do to feel better as quickly as possible.
Let us explore what is happening in your digestive system and how to address it effectively.
Endocrinologist Advise on Metformin-Induced Diarrhea
If you started taking metformin due to diabetes, you probably have some questions now. Such as, does metformin cause diarrhea? What other side effects does metformin have other than diarrhea? The short answer is most of the time, yes. The real question is how to avoid diarrhea and what to expect when to take metformin medication.
In the last 15 years, metformin has become the first-line agent for the treatment of type 2 diabetes. Metformin studies showed good safety data. Diarrhea, however, remains the same as the biggest side effect. Up to 25% of patients suffer metformin-associated gastrointestinal side effects. Approximately 5-10 % of diabetic patients can not tolerate metformin at all.
So, should you stay on it? Read the entire article, and you will be well-versed about metformin side effects. We also need to mention that a lot of people do not have any side effects taking metformin at all. Metformin sometimes works great. In other cases, patients have no efficacy from the medication, but they get a lot of side effects. Some people think that response to metformin could be somewhat heritable.
Common Side Effects
Any person who has ever taken medication is aware that doing so comes with a risk of experiencing a wide range of unpleasant side effects. These side effects can range from annoying to potentially harmful when it comes to metformin, which is one of the most widely used treatments for diabetes. In addition to headaches, common side effects include stomach upset and diarrhea.
Low blood sugar and lactic acidosis are two examples of more serious adverse effects that may occur. Even though the vast majority of people who take metformin medication do not experience any serious side effects, it is essential to have a thorough understanding of the possible dangers prior to beginning treatment.
Patients can be better prepared to deal with any potential adverse effects taking metformin of a treatment if they are aware of those effects and the likelihood that they will occur.
Why does metformin cause diarrhea?
According to Drugs.com, up to 53% of people taking immediate-release metformin experience gastrointestinal side effects. This highlights how common digestive symptoms are among new users of the medication. One study, cited by WebMD, found that 53% of people taking the standard (immediate-release) metformin formulation experienced diarrhea, compared with just 10% on the extended-release formulation.
Here is why metformin causes diarrhea in patients with diabetes: it increases the amount of glucose absorbed by the intestines. This might result in the production of lactic acid, which is known to irritate the intestinal system. Metformin is known to raise levels of another hormone known as incretin. Additionally, incretins are capable of causing diarrhea.
You may recall from earlier articles on trulicity or ozempic that incretins perform a variety of functions. In addition, taking metformin can increase bile acid production in the intestines, which can alter stool consistency. The bacterial flora in the intestinal system may be altered as a result of taking metformin. In most cases, this helps improve diabetes, but it also has the potential to lead to diarrhea because it alters the intestinal flora.
Last but not least, the structure of metformin is comparable to that of serotonin receptors. The release of serotonin can also cause symptoms such as nausea, vomiting, and diarrhea. Some patients with diabetes develop late-onset chronic diarrhea due to this medication. The reasons for this are unknown. Diarrhea is normal and expected in the first 2 weeks of metformin use, but chronic metformin-induced diarrhea is not acceptable in most cases. Remember, some other medications can also cause diarrhea, including Ozempic, Trulicity, and Mounjaro.
If you have tried metformin and are struggling with side effects, some people find that berberine-based supplements, such as SugarMD Super Berberine, can be a helpful addition to a healthy routine. However, always discuss any changes with your doctor first.
Berberine is a plant-based alkaloid that has been used for centuries in traditional Chinese medicine to help regulate blood sugar levels. And SugarMD Super Berberine is made with 100% pure dihydroberberine extract, which is 5 times more absorbable than regular berberine, and is standardized to 98% purity. You will only need to take 1 capsule of SugarMD Super Berberine a day, compared to 3-4 capsules of regular berberine.
Treating Chronic Diarrhea Due to Metformin:
Here are some steps you can take for treating chronic diarrhea due to Metformin:
- Start with a very low dose of metformin if you have diabetes.
- Try to use the extended-release form of metformin instead of regular metformin. Modified-release formulations of metformin can spread the absorption of metformin along the gut. Therefore, it reduces local drug concentrations, with the aim of increasing its tolerability.
- Start taking not more than 500 mg a day.
- Start taking metformin always with meals in your healthy diabetic diet.
- Eat a healthy diet that has fewer processed foods.
- The evening meal is the best time to start taking metformin.
- If you are taking instant-release tablets, swallow whole. Do not try to chew, crush, or break the tablet.
- If you have a swallowing problem, talk to your diabetes doctor. Suspension for metformin is also available. For the suspension, you will need to shake well before the use.
- Only titrate the metformin dose up after side effects subside
- You can increase metformin to 500 mg twice daily with meals only if 500 mg is tolerated with the evening meal.
- If twice a day is tolerated with 500 mg tablets, you can increase it to 2 tablets twice a day for maximum efficacy.
- More than 2000 mg of metformin is not going to be any more effective than 2000 mg.
- Sometimes giving a break to taking metformin for a few weeks may help reduce diarrhea. Restarting metformin may not give diarrhea again after his break. Remember to add it to your meals as part of your healthy diet.
- If diarrhea happens or you are throwing up, call your doctor. You will need to drink more fluids to keep from losing too much fluid.
- If you are 65 or older, use this drug with care. You could have more side effects.
How To Stop Taking Metformin?
If you're like many people with diabetes out there, you've been taking metformin for years. It's sometimes the only thing that keeps your blood sugar in check. But lately, you've been thinking about stopping. Maybe you don't like the way it makes you feel. Or maybe you're just tired of having to take many pills every day. Whatever the reason, quitting it due to metformin's side effects can be a tough decision.
The most important first step is to speak with your doctor. There are several alternatives and combination approaches available, and your healthcare provider can help you find what works best for your situation. Some people find that supplements like SugarMD Super Berberine, used alongside a healthy diet and lifestyle, can support blood sugar management as part of a broader plan.
In fact, in a recent clinical study, participants who took dihydroberberine and Ceylon Cinnamon for three months saw a significant decrease in their blood sugar levels.
Still, it is advisable to always make medication changes under medical supervision.
What Other Side Effects Does It Cause?
Not only diarrhea but also nausea or vomiting can happen. Excessive gas is not uncommon. Some people describe chest discomfort with this medication. This chest discomfort is not typically related to heart problems unless there is underlying heart disease. Metformin can also cause flushing and palpitations. 5 to 6% of people report headaches as a side effect.
Up to 10% of people can report changes in the tasting of food. 1 to 10% of patients may have excessive sweating, abdominal pain, or indigestion. B12 levels can go down. Metformin can very rarely cause low blood sugar in people with diabetes. Lactic acidosis can be concerning for many patients. On the other hand, the incidence of lactic acidosis with metformin is extremely rare.
Unless a contraindication exists to the use of metformin, lactic acidosis should not be a fear factor. In any case please call your diabetes specialist if you have signs of too much lactic acid in the blood (lactic acidosis) like fast breathing, fast or slow heartbeat, a heartbeat that does not feel normal, very bad upset stomach or throwing up, feeling very sleepy, shortness of breath, feeling very tired or weak, very bad dizziness, feeling cold, or muscle pain or cramps.
Contraindications
As any diabetes expert will tell you, one of the most important things to know about diabetes is that it has contraindications that can adversely affect your health. In other words, there are certain things diabetic people should avoid if you have diabetes. And one of those things is metformin. Metformin is a medication used to treat diabetes, but it can actually make diabetes worse.
That's because metformin can cause a build-up of lactic acid in the blood, which can lead to a condition called lactic acidosis. Lactic acidosis is a potentially fatal condition, so it's definitely something you want to avoid if you have diabetes. So if you're looking for a way to keep your diabetes under control, make sure you steer clear of metformin medication if you have these contraindications. Do not take metformin if you have the following. Side effects will be dramatically higher in these cases:
- Impaired renal function with chronic kidney disease stage IV. Early-stage kidney disease is not a contraindication to metformin. Metformin also does not increase the risk of kidney failure. When you are on metformin, diarrhea can lead to dehydration. Dehydration can trigger kidney function worsening.
- Active or progressive liver disease
- Active alcohol abuse
- Unstable or acute heart failure. When you end up in the hospital due to heart failure, this is typically an acute heart failure.
- Past history of lactic acidosis during metformin therapy
- Decreased tissue perfusion or hemodynamic instability due to infection or other causes
What happens if you miss a dose?
If you're like most people with diabetes, you probably have a strict routine medication regimen that you follow to keep your blood sugar levels under control. But what happens when you miss a dose of your diabetes medication? Should you just skip it and hope for the best? Actually, the best course of action is to simply continue with your normal routine the next day.
This means that if you normally take your medication in the morning, you should take it as soon as you remember. And if you normally take it at night, you should take it at your usual bedtime. By staying on schedule, you'll help to keep your blood sugar levels more stable and avoid any potential complications. If you're like most people, you probably don't want to double up on your doses of medication, especially if it means increasing the likelihood of side effects.
However, when it comes to diabetes medications, taking two doses at the same time could actually be beneficial. That's because diabetes medications can often cause diarrhea, and by taking two doses at once, you can help to reduce the amount of diarrhea you experience. Of course, this is only recommended if your doctor approves, but it's something to keep in mind if you're struggling with diabetes-related diarrhea.
Can You Take Metformin with Insulin?
Many insulin users are curious whether they can take metformin with insulin. The answer is a resounding yes! In fact, taking insulin and metformin together can actually help to improve blood sugar control. When used in combination, these two medications can help keep blood sugar levels stable.
As a result, insulin users taking metformin may need less insulin overall. So if you're insulin-dependent and looking for ways to improve your blood sugar control, ask your doctor about adding metformin to your medication treatment regimen.
Can you Take Metformin Along With Berberine?
Berberine is a plant-based compound that some research suggests may support healthy blood sugar levels when used alongside a balanced diet and lifestyle. So, can you take metformin along with berberine? Many people do, and some studies suggest the combination may offer additional benefits for blood sugar management.
One study found that participants taking both metformin and berberine had lower insulin levels compared to those taking metformin alone. Another study observed a potential association with improved kidney health markers. As always, talk to your doctor before adding any supplement to your regimen, especially if you're already on prescription medication. If you are curious about adding berberine to your routine, SugarMD Super Berberine is one option worth discussing with your healthcare provider.
How to store?
Metformin is an important medication for people with diabetes, in addition to a healthy diet, but it needs to be stored properly to remain effective. That's why you should always store metformin at room temperature in a dry place. And under no circumstances should you keep it in the bathroom, where the humidity can cause it to degrade. So make sure to put it somewhere safe and dry, like a kitchen cabinet or bedroom dresser.
That way, you can be sure that your diabetes medication will be there when you need it. Keep metformin medication away from children and pets even if they have diabetes. Pay attention to metformin’s expiration date. Typically, patients will have piles of metformin sitting in their homes. It can be very effective at managing blood sugar levels, but it can also cause side effects such as nausea and diarrhea.
As a result, some patients may decide to stop taking metformin. However, this doesn't mean that they're off the diabetes meds forever. If their blood sugar levels begin to rise again, their physician may restart their metformin prescription. And since the medication has a relatively long shelf life, there's a good chance that their previous prescription will still be valid. So if you're thinking about quitting metformin, think twice.
You may just end up taking it again down the road. Metformin medication may not be the best drug for you if you are prone to diarrhea.
Frequently Asked Questions
Why does metformin cause diarrhea?
Metformin can increase glucose absorption in the intestines, raise incretin hormone levels, boost bile acid production, and alter the gut's bacterial flora, all of which can contribute to diarrhea. Its structural similarity to serotonin receptors may also trigger nausea, vomiting, and loose stools.
Will diarrhea from metformin go away on its own?
Diarrhea is normal and expected during the first two weeks of metformin use and often improves as your body adjusts. However, chronic metformin-induced diarrhea that persists beyond that period is not considered acceptable and should be discussed with your doctor.
What can I do to reduce diarrhea from metformin?
Starting with a low dose of 500 mg and increasing gradually, always taking metformin with meals, and switching to the extended-release formulation are the most effective strategies for reducing digestive side effects.
Is extended-release metformin easier on the stomach?
Yes, extended-release metformin spreads absorption along the gut, reducing local drug concentrations and improving tolerability. One study found that only 10% of people on the extended-release form experienced diarrhea, compared to 53% on the immediate-release form.
What other side effects does metformin cause?
Beyond diarrhea, metformin can cause nausea, vomiting, excessive gas, headaches, flushing, palpitations, and changes in food taste. It can also lower vitamin B12 levels over time and, in very rare cases, may contribute to lactic acidosis.
Can I take metformin with insulin?
Yes, metformin and insulin can be taken together and may actually improve blood sugar control when combined. People using both medications may also find they need less insulin overall.
Can metformin be taken alongside berberine?
Many people do take both, and some studies suggest the combination may offer additional benefits for blood sugar management. Always speak with your doctor before adding any supplement to your regimen, especially when you are already on a prescription medication.
Who should not take metformin?
Metformin is contraindicated for people with stage IV chronic kidney disease, active liver disease, active alcohol abuse, unstable or acute heart failure, or a prior history of lactic acidosis while on metformin. Diarrhea-related dehydration can also worsen kidney function, so these risks are especially important to discuss with your doctor.
SugarMD Advanced Glucose Support, Super Berberine, and Neuropathy Support may help regulate your blood sugar and prevent diabetic complications. If you want to learn more about this topic, check out our metformin review article. 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.