Supplements

Comparing Berberine vs. Metformin: Which Is Better for Managing Diabetes?

Written by Lauren Manaker, RDN, CLE
Medically Reviewed by Felicia Newell, M.S., RDN

Updated on October 25, 2024

To say that metformin is a popular drug is an understatement. The demand for this diabetes drug has steadily increased year after year, with the number of prescriptions in the U.S. increasing from 40 million in 2004 to over 92 million in 2020. That’s a 130% increase in just 16 years (1).

And as of late, there’s another powerful contender to metformin: berberine.

Both metformin and berberine are renowned for their ability to regulate glucose metabolism, having transformed the lives of potentially millions across the globe. But which one is right for you? Join us as we delve into their similarities and differences—from uses and health benefits to side effects and drug interactions.

Table Of Contents

Uses of Berberine & Metformin

Used in Chinese and Ayurvedic medicine since around 3000 BC, berberine is an alkaloid compound that’s naturally found in certain plants like barberry, goldenseal, Oregon grape, and tree turmeric (2). It’s a yellow-colored compound that gives these plants their distinct yellow hue.

Berberine is most known for its ability to activate the enzyme AMP-activated protein kinase (AMPK). Often called the “metabolic master switch”, AMPK plays an important role in (3, 4):

  • Decreasing blood sugar
  • Improving glucose metabolism
  • Supporting healthy weight management
  • Reducing inflammation

This, in turn, helps manage blood sugar and, in turn, type 2 diabetes.

Metformin, on the other hand, is a prescription medication that was first discovered in 1957 by French physician, Jean Stearne. It wasn’t until 38 years later—in 1995—that it was finally approved for use in the United States (5).

Its number one use is for the management of type 2 diabetes. Metformin works by decreasing the amount of glucose produced by the liver and increasing insulin sensitivity, helping to keep blood sugar levels in check (6, 7).

It’s also used for other conditions like gestational diabetes, Polycystic Ovary Syndrome, and obesity. Some also use it to reduce the risk of developing type 2 diabetes (6).

Berberine vs. Metformin: Which Is Better?

So, how do berberine and metformin stack up when they are both put to a head-to-head test?

One clinical trial compared the effects of berberine and metformin by giving people with type 2 diabetes either metformin or berberine for 3 months (8).

A screenshot of an NCBI study titled "Efficacy of Berberine in Patients with Type 2 Diabetes"

The results showed both interventions offered similar blood sugar-supporting benefits, without any significant difference between the two.

Similar findings were reported in another clinical trial, which showed that berberine supplementation resulted in lower fasting blood glucose, hemoglobin A(1c), triglyceride, and insulin levels similar to those who took metformin (9). 

And based on a systematic review of 12 studies, berberine appears to have moderate impacts on reducing body weight (10). Other data suggest berberine may have greater potential to reduce the risk of cardiovascular disease than metformin among those with Polycystic Ovarian Syndrome (11). Although more robust, long-term human trials are still needed, early data is showing promise.

Benefits Beyond Blood Sugar Regulation

The benefits associated with taking metformin and berberine don’t stop at blood glucose control. Both interventions may offer even more health benefits.

Additional benefits associated with taking berberine may include (12):

  • Weight management support
  • Heart health support
  • May help reduce depression
  • May help treat nonalcoholic fatty liver disease (NAFLD)
  • Can help with the prevention of atherosclerosis
  • Potential anti-cancer, anti-inflammatory, and anti-diabetic properties
  • Can aid in restoring the gut’s microbiome

Additional benefits associated with taking metformin may include (6, 13):

  • Heart health support
  • Weight management support
  • May help reduce risk of cancer in those with type 2 diabetes (specifically colon, breast, and prostate)
  • Can help lower risk of dementia and stroke
  • May slow aging

Safety & Side Effects of Berberine & Metformin

While both berberine and metformin have exceptional health benefits, there are some important side effects to know about each…

Common Side Effects of Berberine

Berberine intake is linked to gastrointestinal distress, like nausea, vomiting, abdominal pain, and diarrhea.

Some may also experience hypoglycemia, as berberine can lower blood sugar levels. If you have diabetes or take medication to control blood sugar levels, monitor your blood sugar closely while taking berberine and inform your healthcare provider so they can ensure there are no potential contraindications.

There have been rare reports of liver damage associated with berberine use. If you experience yellowing of the skin or eyes, dark urine, light stool, abdominal pain, or fatigue, stop taking berberine and call your healthcare provider immediately. These could be signs of liver damage.

Common Side Effects of Metformin

The most common side effects of metformin—meaning they happen in more than 1 in 100 people—are gastrointestinal and include diarrhea, bloating, gas, and nausea. These side effects are usually mild and resolve with time. If they persist or become severe, contact your doctor. Other common side effects include headache, dizziness, a vitamin B12 deficiency, and low blood sugar (hypoglycemia) (14).

Potential Drug Interactions & Contraindications

There are a few drug interactions to be aware of when taking metformin. First, alcohol can increase the risk of lactic acidosis, so it’s best to avoid drinking while on metformin. Second, certain antibiotics (such as tetracyclines) can decrease the absorption of metformin, so it’s important to take them at least two hours apart. Metformin can interact with other diabetes medications (such as insulin or sulfonylureas), so be sure to talk to your doctor about any potential drug interactions before starting metformin.

There is limited research on the potential interactions between metformin and berberine. Berberine may decrease the effectiveness of metformin when used together. Berberine can interact with other prescription medications and increase or decrease levels of these medicines in the blood due to its effects on specific enzymes in the blood (15).

The Bottom Line

Both metformin and berberine can be effective additions to your blood sugar-managing diet, especially if you have diabetes. Ultimately, the decision to opt for one intervention over another should be made with your healthcare provider to ensure that you’re choosing the method that’s right for your needs.

If your provider has encouraged you to include berberine in your plan of care, opting for a high-quality berberine supplement is key.

Lauren Manaker
Article by

Lauren Manaker

Lauren Manaker is an award-winning registered dietitian (RDN), certified lactation educator (CLE), author, and speaker with over 20 years of experience. She earned her BS in Food Science and Human Nutrition from the University of Florida (go Gators!) and an MS in Clinical Nutrition from Rush University in Chicago.

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    Medical Disclaimer

    This content is for informational and educational purposes only. It is not intended to provide medical advice or to take the place of such advice or treatment from a personal physician. All readers/viewers of this content are advised to consult their doctors or qualified health professionals regarding specific health questions. Neither Dr. Chad Walding nor the publisher of this content takes responsibility for possible health consequences of any person or persons reading or following the information in this educational content. All viewers of this content, especially those taking prescription or over-the-counter medications, should consult their physicians before beginning any nutrition, supplement, or lifestyle program.

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