Written by Amy Brownstein, MS, RD
In searching for methods to manage and reverse type 2 diabetes, you may have encountered the supplement berberine. Berberine is a natural compound found in plants that may benefit blood sugar levels. In particular, berberine may be a beneficial alternative for people newly diagnosed with type 2 diabetes looking to reduce their blood sugar levels. Let’s discuss berberine — what it is, how it works, its benefits, and what you should know before adding this supplement to your daily routine.
The information shared in this article is educational. Always talk to your medical provider before making any medication changes or starting a new supplement.
What is berberine?
Berberine is the main active ingredient in the herb Rhizoma Coptidis. This herb has been used in traditional treatments of diabetes and hyperglycemia due to its hypoglycemic effects, or its ability to reduce blood sugar levels. 
Berberine is associated with improved blood glucose and HbA1c
Berberine improves HbA1c, fasting blood glucose, and two-hour postprandial (after a meal) blood glucose levels in people with type 2 diabetes. The higher your blood sugar and HbA1c values, the greater the effect of berberine. What’s more, people under the age of 60 appear more responsive to the benefits of berberine supplementation.[2,3]
Multiple systematic reviews (studies examining multiple studies) have found that berberine lowers HbA1c by 0.38%, fasting blood glucose by 5.22 mg/dL, and two-hour postprandial glucose by 10.26 mg/dL. [1,2,4]
Berberine and antidiabetic medications may have similar effects on blood glucose
Berberine may be as effective at lowering blood glucose levels as traditional antidiabetic medications, such as metformin, thiazolidinediones, and sulfonylureas. Systematic reviews found no significant difference in the effect on glucose metabolism between people taking berberine alone or other oral hypoglycemic medications. [1,3,5]
We never recommend stopping medications. Always talk to your medical provider before making any changes or discontinuing your medications.
Taking berberine and antidiabetic medications together may be the most effective
When berberine and metformin were taken together, the effects on HbA1c, fasting blood glucose, and two-hour postprandial blood glucose were even more significant. According to one systematic review, the combined use of berberine and an antidiabetic agent lowered HbA1c by 0.91%, fasting blood glucose by 19.08 mg/dL, and two-hour postprandial by 24.12 mg/dL.  Another systematic review supports these results: co-use of berberine and oral hypoglycemic medication decreased HbA1c by 0.53%, fasting blood glucose by 12.42 mg/dL, and postprandial blood glucose by 18.9 mg/dL. 
How does berberine lower blood glucose?
Berberine activates an AMP-protein kinase (AMPK) in glucose metabolism and energy production. AMPK is an enzyme (a protein that assists cells with carrying out their functions) in the body that helps with cell energy signaling. When cellular energy levels are low, AMPK is activated and tells the cells to remove glucose from the bloodstream or break down fatty acids to provide energy.  So by activating AMPK, berberine encourages greater removal of glucose, which leads to lower blood sugar levels.
Berberine works like metformin: both activate AMPK to encourage muscles to take up glucose and improve insulin sensitivity. 
Unlike diabetes medications such as sulfonylureas or glinides, which can cause hypoglycemia (low blood sugar), berberine influences the release of insulin in a way that prevents hypoglycemia. Berberine only works under hyperglycemic or high-glucose conditions. 
Berberine may improve insulin sensitivity
Berberine supplementation also improves insulin resistance.  Fasting insulin levels and the homeostatic model assessment for insulin resistance calculation (HOMA-IR) are two metrics for evaluating insulin resistance. Research shows berberine supplementation decreases fasting insulin levels and HOMA-IR, indicating improved insulin sensitivity. 
Additionally, in people with more advanced type 2 diabetes, berberine may revive damaged islet cells.  Islet cells, which include alpha and beta-cells, are the cells in the pancreas that produce hormones. Alpha cells make the hormone glucagon, which releases glucose into the bloodstream, and beta cells make the hormone insulin, which lowers the glucose level in the blood. In more advanced type 2 diabetes, beta-cell function is worse, so the beneficial effects of berberine on pancreatic islet cells may be an important component for improving insulin sensitivity.
Does berberine have any other health benefits?
Besides its effect on blood sugar levels, berberine has anti-inflammatory, antiobesity, and lipid-lowering effects.  Additionally, berberine may improve liver function in people with fatty liver disease. 
Berberine and weight loss
Berberine is associated with weight loss and changes in body composition and body mass index (BMI). One small study conducted in the United States observed an average weight loss of five pounds in otherwise healthy people with obesity. Participants were instructed to take 500 milligrams of berberine three times daily for 12 weeks and to maintain their regular eating and exercise habits. While there was no control group in this study, results are in line with previous research.  In particular, one randomized control trial observed significant weight loss in people newly diagnosed with type 2 diabetes taking 500 milligrams of berberine twice daily for 12 weeks. Furthermore, there was a statistically significant difference in weight loss and BMI between the treatment and placebo group. 
Berberine may help reduce visceral fat and central obesity
Berberine may improve insulin sensitivity and reduce visceral fat (the fat that coats the organs in your abdomen) and inflammation in people with metabolic syndrome. Metabolic syndrome comprises a group of health conditions — including high blood pressure, high blood sugar, excess abdominal fat, and abnormal cholesterol — that increase the risk of developing heart disease, stroke, and diabetes. A person is diagnosed with metabolic syndrome if they have three or more of the associated health conditions. Cellular research shows that berberine may prevent fat cells from increasing and enlarging. Larger fat cells are associated with greater insulin resistance and inflammation. Clinical studies confirm the influence of berberine on visceral fat: waist circumference and BMI decreased in people with metabolic syndrome who took berberine for three months. 
Berberine positively influences dyslipidemia
Berberine improves dyslipidemia (abnormally high cholesterol levels). Supplementing with berberine may lower total cholesterol, triglycerides, and low-density lipoprotein (LDL) or “bad” cholesterol, and raise high-density lipoprotein (HDL) or “good” cholesterol levels. [1,7] One study demonstrated a 23% decrease in triglycerides and a 12.2% decrease in cholesterol levels in men with obesity who took 500 milligrams of berberine three times per day for 12 weeks.  Another study of people with hypercholesterolemia (abnormally high LDL cholesterol) found that supplementing with berberine reduced cholesterol by 29%, triglycerides by 35%, and LDL cholesterol by 25%. 
Berberine with lifestyle interventions is better at lowering lipid levels than lifestyle interventions alone. Similarly, a combined treatment of lipid-lowering medication and berberine reduces lipid levels more effectively than just lipid-lowering medications. And compared to lipid-lowering drugs, berberine appears more successful at lowering triglyceride levels and increasing HDL cholesterol. 
Berberine and non-alcoholic fatty liver disease
Non-alcoholic fatty liver disease (NAFLD) is one of the leading causes of chronic liver disease. It occurs when fat accumulates in the liver and is accompanied by insulin resistance and impaired glucose and lipid metabolism.  Additionally, NAFLD is correlated with type 2 diabetes and cardiovascular disease.
One clinical trial comparing the effect of lifestyle interventions combined with berberine or pioglitazone (an antidiabetic medication from the thiazolidinedione class that reduces blood sugar by making the body more sensitive to insulin) showed similar results in reducing liver fat content and the liver enzymes ALT and AST. Likewise, similar changes in blood glucose control and insulin sensitivity were observed between the two groups. Both groups (lifestyle and berberine, and lifestyle and pioglitazone) achieved better results than just lifestyle interventions alone. However, weight loss and changes in body composition (waist circumference and BMI) were the most significant in the lifestyle and berberine group. 
How should berberine be used?
Most of the research on berberine uses doses of 1.5 to 2 grams per day. But supplementing with less than 1 gram per day also shows promising effects on fasting blood glucose levels, especially in people who have had type 2 diabetes for less than five years.  Research suggests that supplementing for at least three months may be the most effective for influencing blood glucose levels. 
Berberine in doses of 300 to 500 milligrams two to three times per day before meals effectively reduces fasting blood glucose and postprandial blood glucose, particularly in people newly diagnosed with type 2 diabetes. [6,14] Studies have evaluated the effectiveness and safety of berberine for up to six months. However, beyond that, it is unclear if berberine is associated with any long-term issues.
Side effects and supplement safety
Always consult your healthcare provider before starting or stopping a medication. And double check with your doctor that berberine is safe for you to use.
The FDA does not regulate supplements, so it is important to verify that what you are getting is berberine.
Berberine has few side effects. Some people taking berberine have noted abdominal pain. But not many adverse effects have been reported.  Adjusting the dosage appears effective for reducing gastrointestinal side effects associated with berberine.
Can anyone take berberine?
Overall, berberine appears safe to use in most people. However, berberine is not recommended for people who are pregnant or breastfeeding.
Does berberine interact with any medications?
The risk of hypoglycemia may increase if taking both berberine and an antidiabetic medication together. In particular, berberine and metformin may interact with each other. Specifically, it is possible that taking berberine two hours before metformin increases the amount of metformin in the body. However, simultaneously taking berberine and metformin does not appear to have this effect. Additional research is needed to understand the interaction between berberine and metformin fully. 
Similarly, as berberine is processed in the liver, it may interact with other medications that are metabolized (broken down) by the liver. Talk to your doctor about possible medication interactions before trying berberine.
Limitations of the research
Many of the studies on berberine for glucose control were conducted in China, so this medicinal plant may be less effective at lowering blood glucose levels in other populations. Similarly, significant variation between the different studies makes establishing broad recommendations for supplement dosage and duration difficult.
Additionally, more research is needed on the long-term use of berberine, as only a few studies exist that examine the safety and efficacy of berberine for more than six months.
Which brand of berberine should you take?
Always consult your medical provider before starting a new supplement to ensure it will be safe and effective for you.
If you choose to take berberine, we recommend Ancient Bliss. Ancient Bliss uses organic and naturally sourced compounds in their supplements. And Ancient Bliss’ products are GMP-certified and undergo a rigorous quality assurance process to provide a safe and effective product. Use this link for a 10% discount on berberine supplements.
Let's recap: berberine and type 2 diabetes
Berberine significantly lowers blood glucose, HbA1c, and two-hour postprandial glucose when used alone or with antidiabetic medication. Moreover, berberine has other beneficial effects that may reduce risk factors associated with insulin resistance and other comorbidities, such as hyperlipidemia and fatty liver disease. Berberine may be more effective in people newly diagnosed with type 2 diabetes who are younger than 60 years of age.
Berberine is safe to use, with only mild gastrointestinal symptoms reported. Currently, supplementing with 1.5 to 2 grams daily appears safe and is associated with glucose metabolism-related benefits. As always, consult your medical provider before starting a new supplement.