Metformin and berberine are two powerful blood sugar-lowering compounds, which is important given that managing blood glucose (sugar) levels is crucial for preventing prediabetes and managing type 2 diabetes (1). Keeping glucose levels in check is also key for weight management and overall chronic disease prevention (2). When it comes to which intervention—metformin vs. berberine—to choose for managing both blood glucose and weight, you’ll want to consider a few key pieces of information.
Ahead, health professionals compare the similarities, differences, potential benefits, and possible side effects of metformin and berberine.
Metformin vs. Berberine: The Main Differences
The biggest difference between the two pills? Metformin is a prescription medication, while berberine is an herbal supplement you can buy over the counter.
“Berberine is a natural alternative, while metformin has more extensive, long-term safety data available and widespread availability,” says Menka Gupta, M.D., FMCP. “Metformin is often favored as the initial choice by healthcare professionals.”
Metformin
Metformin received U.S. Food and Drug Administration (FDA) approval in the mid-90s for lowering blood sugar levels in people with type 2 diabetes, though it has some off-label uses—right now it’s being studied for longevity (3). Its use in the U.S. is on the rise, with the number of prescriptions nearly doubling from about 41 million in 2004 to more than 91 million in 2021 (4).
Type 2 diabetes is characterized by high blood sugar levels and insulin resistance, both of which are also linked to obesity and weight gain (2). Metformin lowers blood sugar levels and helps increase insulin sensitivity (5).
“Metformin works by primarily reducing the liver’s ability to release glucose from its stores,” Menka says. “Metformin has also been shown to inhibit the absorption of glucose from the intestines.”
About the Experts
Menka Gupta, M.D., FMCP, a functional medicine doctor with over 20 years of experience, and founder of NutraNourish. She has experience treating people with anxiety, depression, insomnia, digestive disorders, chronic fatigue, thyroid issues, and diabetes.
Lauren Thayer, R.N., a registered nurse at Health Canal. She specializes in pediatrics, rehabilitation, and as of late, clinical informatics.
Berberine
Berberine is an herbal supplement you can buy over the counter, including online. It’s a compound derived from various plants, such as barberry, goldenseal, goldthread, Oregon grape, phellodendron, and tree turmeric (6).
“Berberine activates the AMP-activated protein kinase (AMPK),” Lauren Thayer, R.N. says. AMPK helps to regulate metabolism and blood sugar levels in the body. “This activation process is believed to be what helps treat diabetes,” she says, explaining a few biomarkers—including Hemoglobin A1c and cholesterol levels—may improve after taking berberine.
If you’re taking metformin, don’t take berberine without first consulting your doctor. Using a combination of the two could cause hypoglycemia, where blood sugar drops too low.
Which Is Best for Treating Diabetes?
In various studies, berberine has been shown to have similar effects as metformin in people with type 2 diabetes (7, 8).
Both compounds have been shown to do the following:
Lower fasting glucose: blood sugar levels after fasting (8, 9)
Lower postprandial glucose: blood sugar levels after eating (8, 9)
Lower hemoglobin A1c: a measure of average glucose levels over about three months (8, 10)
Lower fasting triglycerides: lipids (fats) in the blood after fasting (11, 9)
Improving all of these biomarkers is beneficial for longevity, metabolic health, weight loss, and more (16).
“Berberine helps reduce inflammation,” Menka says. “Its anti-inflammatory properties help treat diabetes and other inflammation-related health conditions. Research also suggests that berberine could help lower LDL cholesterol and triglyceride levels. It does so by affecting lipid metabolism.”
Metformin has a long-standing history of helping with these same biomarkers. Plus, both metformin and berberine may help prevent cancer, but more research is needed (17, 18).
However, berberine does have one interesting advantage, Menka notes. “Berberine has an antibacterial action that seems to remove the harmful bacteria in the gut and enhance the growth of healthy bacteria (19). This improvement in gut microbiome balance leads to improved gut health.”
Ultimately, research on berberine is still in the relatively early stages, whereas more research is available on the efficacy and safety of metformin.
“Berberine is not approved by the FDA to treat any conditions and is considered a dietary supplement,” Thayer explains. “Metformin is FDA approved and is regulated and tested for safety and effectiveness. While Berberine is generally considered safe for adults, it has not undergone the same rigorous testing that metformin has.”
Both metformin and berberine can cause side effects, often related to the gut.
The most common side effects of Metformin include (20):
abdominal pain
diarrhea
loss of appetite
metallic taste
nausea
vomiting
After taking berberine, some people experience side effects including (21):
abdominal pain
constipation
diarrhea
gas
stomach upset
A Longer Life? Sounds Pretty Good.
Metformin, now available from Hone, may help you ward off age-related illnesses. Connect with a doctor and get treatment delivered—without leaving home.
Metformin is a prescription medication, while berberine is an herbal supplement you can buy over the counter. Both compounds help lower blood sugar and improve biomarkers related to longevity, metabolic health, and weight management. Metformin is approved for the treatment of type 2 diabetes, while berberine is not approved to treat any disease.
If you have prediabetes or type 2 diabetes, your doctor may prescribe metformin. However, if your doctor says you don’t need metformin, you may consider taking berberine to help manage blood sugar levels and prevent the development of metabolic health issues. As always, speak with your physician ahead of introducing any new supplement into your diet.
Jennifer Chesak is a freelance science and medical journalist and editor who covers the pandemic, chronic health issues, medical rights, healthcare, and the scientific evidence around health and wellness trends. Her work has appeared in Washington Post, Prevention, Healthline, Health, The Daily Beast, Runner's World, Greatist, Real Simple, and more.
