Berberine Vs Metformin

People with type 2 diabetes have probably heard of both Metformin and Berberine because they have a lot in common. Both are very good at blood sugar control, inexpensive, and have been around for years. But one is an FDA-approved medication and the other is a natural supplement. So what are the differences? We compare Berberine vs Metformin and look at how they work, the different beneficial effects they have, and why one may be a better option than the other.

What is Berberine?

Berberine is yellow-colored, bitter-tasting compound found in roots and stem barks of different plants. These plants include European barberry, phellodendron (cork tree), goldenseal, tree turmeric and goldthread.

barberry plant with fruit
Photo of the plant Barberry

It was first isolated in the 1900s but berberine plants have been used as natural medicine for hundreds of years. For instance, traditional Chinese medicine used berberine to treat inflammation and infectious diseases that were common in ancient China.

The strong yellow color of Berberine plants also made it a widely used dye long ago, especially for dying wool.

What is Metformin?

Metformin Hydrochloride is a first line treatment for Type 2 diabetes to improve blood glucose levels. 

Metformin was originally made from natural compounds in a plant called Galega officinalis, or French lilac or goat’s rue. It’s been reported that this herb was used to treat frequent urinating and halitosis (bad breath) as far back as ancient Egypt and the Middle Ages.

close up of lilac flowers
Photo of Lilac flowers

Today, Metformin is made synthetically and is a generic drug you can find under common brands Glucophage, Frotamet, and Riomet.

Metformin is also used around the world to treat diabetes and is included in the WHO Model List of Essential Medicines.

Dosage of Berberine and Metformin for Diabetes

Metformin is usually prescribed with a starting dose of 850mg tables taken once a day and after a month, increased to 850mg twice a day. This is to see how the person responds to the medication and watch for any unusual side effects.

But healthcare providers can increase/decrease the dosage throughout treatment based on blood glucose targets and overall health.

Berberine has been used in doses of up to 2 grams daily for 8 weeks. It’s most often given in doses of 0.4-1.5 grams daily for a duration of 2 weeks to 2 years. And these total daily dosages are usually divided into 2 or 3 doses throughout the day.

Berberine vs Metformin: How They’re Similar


Both Metformin and Berberine have been shown effective in lowering blood glucose levels.

This review of clinical trials found that Berberine exhibited significant reductions in participants’ fasting blood glucose (FBG), fasting plasma glucose (FPG), Hemoglobin A1C (HbA1c).

Those results are consistent with this study that treated type 2 diabetes patients with similar doses of Berberine or Metformin. And that study found saw significant decreases in FBG, FPG, and HbA1c in the Berberine group, and Berberine was just as effective as Metformin.

Metformin lowers blood glucose levels by decreasing the glucose created by the liver and reducing the glucose absorbed in the gastrointestinal tract. 

Several studies have shown Metformin’s effectiveness in controlling blood glucose in people with Type 2 diabetes. This includes this large study on non-insulin dependent diabetes patients showing significant decreases in FPG and HbA1c levels.

How They Work

The blood-glucose lowering effect of Berberine is from its ability to increase insulin receptor expression in blood cells of people with type 2 diabetes. In other words, it increases insulin sensitivity.

In addition, research on mice and rats with insulin resistance found that Berberine activated an enzyme called AMP-activated protein kinase. This enzyme contributed to better glucose absorption in muscles, less glucose created by the liver and had a lipid lowering effect.

Similarly, Metformin lowers both blood sugar levels by lowering the glucose created by the liver and reducing glucose absorption by intestines. 

It also increases glucose uptake and usage within the limbs, which helps lower blood glucose levels.

Berberine vs Metformin: How They’re Different

Side Effects

The side effects of berberine and metformin are the biggest areas of difference with Metformin.

The more common side effects with Metformin are diarrhea, gas, nausea or headaches. These usually happen at the beginning of treatment and are generally mild. But talk to your care provider if they’re severe or last for several days.

A more severe side effect of Metformin is lactic acidosis, which is a build up of lactic acid in the blood But based on this review of Metformin-associated lactic acidosis, the incidence of this is quite low and is usually when the person has kidney complications or disease. 

Liver inflammation or damage is also possible. Though they seem very rare based on studies on Metformin-induced hepatitis and hepatotoxicity.

Berberine is generally well tolerated and safe when taken under supervision from your healthcare provider.

But common side effects are mostly gastrointestinal (GI) issues like constipation, abdominal pain, diarrhea, and gas. According to some studies, one possible explanation is that Berberine impacts the gut bacteria and leads to GI issues

Because of its insulin sensitizing effect, Berberine could have adverse impacts when taken with other glucose-lowering diabetes medications. Another reason why it’s important to talk to your care provider before taking any berberine supplement.

Health benefits of Berberine

Studies show that Berberine can provide other beneficial effects that Metformin does not. But know that no Berberine supplement is approved by the FDA to treat health conditions.

Antibacterial Properties

Ancient and traditional medicine have long used Berberine plants for its antibacterial properties, which is supported by studies today.

Research shows that Berberine slows the development of different types bacteria such as staphylococcus and E. coli.


Many studies have shown the anti-tumor effects of Berberine and its potential for cancer prevention.

This is mainly because Berberine can initiate apoptosis, a process of controlled breakdown of cells. Cancer is a scenario where too little apoptosis occurs, resulting in malignant cells that will not die.

Berberine can also slow the proliferation of some cancers cells by regulating the cell cycle and the tumor microenvironment.


The anti-inflammatory effects of Berberine by reducing oxidative stress has been shown in both in vivo and in vitro studies.

This review shows that Berberine can cause a small reduction of C-reactive protein, which is a key marker of systemic inflammation. And that Berberine blocks production of proinflammatory cytokines and tumor necrosis factor.

Health benefits of Metformin

Metformin has been studied for its anti-aging effects.

This comprehensive review describes the large amount of data highlighting the beneficial effects of Metformin against aging and age-related diseases.

It showed that Metformin use can improve nutrient signaling, activate AMP-activated protein kinase to suppress inflammation, and plays a role in reducing oxidative stress.

Should I Take Berberine Instead of Metformin?

Picking between Berberine vs Metformin is something to definitely consult with your healthcare provider.

Both Berberine and Metformin are effective at lowering blood sugar but your care provider can assess which is appropriate based on your health condition, blood glucose targets and overall treatment for diabetes.

A lot of people are on Metformin treatment for their diabetes and it has decades of proven effectiveness and research. Though it does have more side effects than Berberine.

Or if you prefer natural alternatives to Metformin, Berberine is a strong option for improving insulin resistance and blood sugar control.

Keep in mind though that Berberine is only a supplement, is not covered by insurance, and doctors may not be familiar with using it treat diabetes.


How much Berberine to take for diabetes

Berberine supplements can be found from 500mg to 5000mg doses. But there is no standard berberine dosage and will depend on your specific condition. So talk to your care provider about whether you should take berberine and the right dosage for you.

Can berberine replace Metformin?

That will depend on results from taking berberine with supervision from a care provider but it’s certainly possible. Especially when combined with exercise and improved diet, berberine can help you reach healthy blood glucose levels.

Can Berberine damage the liver?

Taking berberine as instructed is generally well tolerated by the body. In fact, studies have shown certain Berberine activity can help protect the liver including against fatty liver disease, cancer and toxins.

Are Berberine and Metformin safe to take long-term?

Both are generally considered safe when taken under instruction. Most studies on Berberine involved taking Berberine for up to two years so more long-term research may be needed. While it’s common for people to take Metformin for years under doctor supervision.

Can you take Berberine and Metformin together?

Talk to your care provider first if you can take both metformin and berberine together. Both include powerful hypoglycemic agents so taken together they could lead to hypoglycemia, which can be dangerous.


Both Berberine and Metformin are effective in blood sugar control and either one could be part of your diabetes care plan.

Taking Metformin lowers blood sugar by decreasing the glucose made by the liver as well as lowering the glucose absorbed in the intestines. And Metformin has been part of the standard of care for diabetes patients for decades because of its safety and effectiveness.

Taking Berberine lowers blood sugar by improving insulin sensitivity and glucose metabolism. And there’s several studies showing the beneficial effects of Berberine on inflammation, infections and even cancer.

Bottom line: picking between Berberine vs Metformin will depend on your preference for natural alternatives and blood sugar levels. So talk to your care provider about these two great options to learn which would be appropriate for your diabetes treatment goals.

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