Berberine vs. Metformin: Are They the Same?

As berberine gains attention as a supplement that can help with a variety of conditions such as obesity and PCOS, you may have heard that it works just as well or even better than metformin to treat Type 2 diabetes.

Functional medicine specialist Layth Tumah, MD, explains the differences between the two.

Berberine vs. metformin

Berberine is a supplement that’s commonly used in traditional Chinese medicine (TCM). As a supplement, it isn’t regulated by the U.S. Food and Drug Administration (FDA). And it isn’t as well-researched as conventional medication like metformin in terms of its long-term use, safety and established dose.

“Metformin is an FDA-approved medication primarily used as a first-line treatment for Type 2 diabetes,” clarifies Dr. Tumah. “It activates a pathway known as AMP-activated protein kinase (AMPK). AMPK decreases hepatic glucose production, increases insulin sensitivity and enhances peripheral glucose uptake.”

While more research is still needed to understand how berberine may work to help manage diabetes, Dr. Tumah says it seems to work along the same AMPK pathway but in a different way. There’s also some evidence that berberine may help lower lipid levels and other metabolic markers.

Metformin benefits

This prescription medication may help:

• Improve blood sugar levels
• Manage prediabetes
• Manage gestational diabetes
• Manage PCOS
• Cause weight loss

“There’s a long-term history of studies that back the use of metformin, with established treatment dose, mechanism of action, safety and side effect profile,” shares Dr. Tumah.

Metformin side effects

Metformin side effects may include mild gastrointestinal side effects, like:

• Nausea
• Diarrhea
• Increased gas
• Bloating
• Stomach pain

Other common side effects include:

• Weight loss
• Headaches
• Metallic taste in your mouth
• Vitamin B12 deficiency

It’s rare, but one severe side effect of metformin is lactic acidosis. This requires immediate medical treatment. A few people also experience hypoglycemia (low blood sugar).

Dr. Tumah says you can reduce your chances of side effects by taking metformin with food or taking the extended-release form. It may also be helpful to start at a lower dose and increase over time.

Berberine benefits

While more research is needed to fully understand the benefits of this popular supplement, it may help:

• Improve blood sugar levels
• Cause weight loss
• Reduce high cholesterol
• Reduce blood pressure
• Improve good gut bacteria

Berberine side effects

Berberine side effects may include:

• Nausea
• Abdominal discomfort
• Constipation
• Diarrhea

Dr. Tumah recommends taking berberine before meals and says that, like metformin, it may be helpful to start with a lower dose if you experience side effects.

Is one better than the other?

Dr. Tumah says it depends on what you’re using it for. When it comes to treating diabetes, he states that metformin is the clear winner, as there’s plenty of research to support how it works. Plus, healthcare providers know the right dosage to prescribe and understand its side effects.

“That being said, using berberine may have some potential benefits on multiple conditions such as obesity and cardiovascular health,” notes Dr. Tumah, who stresses the importance of talking to your healthcare provider before starting any supplement.

“But we need to remember that it’s a supplement,” he continues. “We need to have a realistic expectation that it’s not as effective as conventional medication like metformin for managing blood sugar. Berberine shows promise on multiple metabolic markers, which makes its potential benefits go beyond blood sugar regulation, especially if combined with lifestyle interventions.”