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Effects of Berberine on Diabetes

Michelle Park

October 5, 2009


Diabetes is “a disorder of the endocrine system in which the body is unable to produce insulin (Type 1) or is unable to properly utilize this pancreatic hormone (Type 2)” (Straub, 2006, p. 293). According to Traditional Chinese Medicine, diabetes is called the Wasting-Thirst Syndrome because the most common symptoms “of diabetes are excessive thirst, hunger, and urination” ( The Chinese have been treating diabetes with Chinese herbs for over two thousand years ( One such herb used in Chinese herbal medicines is berberine, which is “a plant alkaloid isolated from the roots and bark of several herbs” ( Berberine has been used by the ancient Chinese as a way to treat diabetes, and with the increase of people with diabetes and their search for treatments for this disorder, questions about berberine’s efficacy and safety as a remedy for diabetes have risen.


The Chemical Structure of Berberine An Oregon grape root—yellow part in the      middle is the berberine.


On the World Wide Web

Berberine is thought to decrease blood glucose in diabetic people. The first research on the effects of berberine on diabetes was conducted in China by Ni Yanxi. Diabetic patients, who had high fasting blood sugar, took berberine orally three times a day for one to three months. The results were that the patients who took berberine were less thirsty and thus “consumed less water and urinated less, had improved strength, and had lower blood pressure; the symptoms declined in correspondence with declining blood levels” (  Berberine has this effect because it prevents the absorption of sugars from the intestine and increases the production of insulin. Also, Ni stated that clinical trials showed doses of 2 grams per day of berberine did not produce any side effects. This information about Ni’s study was presented by the Director of the Institute for Traditional Medicine probably because since he is the director and the Institute “is dedicated to preserving and protecting the world’s traditional medicines through education and training,” ( he has to present information that supports traditional medicine. However, he only mentions one study that supports his belief about the effectiveness of berberine, and one study alone is not sufficient evidence to conclude this idea.

In another website created by a medical doctor, he states the potential benefits of berberine. He cites Sydney’s Garvan Institute’s claim that berberine could be helpful. The Institute conducted research showing that berberine activates an enzyme that is involved in increasing tissue sensitivity to insulin in the muscle and liver, which helps lower blood glucose levels; it is also possible that berberine helps “reduce body weight” ( The doctor goes on to quote the head of Garvan's Diabetes & Obesity Research Program, who states that there have hardly been any reported side effects of berberine, although it has probably been used for centuries. Nonetheless, he warns that despite the prevalence of berberine’s use in traditional medicine and berberine’s possibility as a new treatment for type 2 diabetes, berberine has to go through more clinical tests. The website was probably created because the doctor wants people to buy his berberine supplement called Zyflamend. Also, like the website mentioned above, this website only has one study to support the belief that berberine effectively treats diabetes; yet, it lists other research showing that berberine is good for other health conditions.

 Zyflamend (

While the above two are examples of websites with specific authors, most websites do not name their authors. In fact, most websites with information about berberine are maintained by individuals who simply want to share information they found on the Web about a specific subject with other people who might also be interested in that topic. Thus, some people post this information on their blogs (  Multiple websites use the same article to support the idea that berberine is an effective treatment for diabetes, and as a result, the websites all say berberine is from the bark and roots of certain plants and lowers blood glucose level by activating an enzyme that enhances body tissues’ sensitivity to insulin ( Furthermore, many websites emphasis that berberine has few known side effects; the majority of the websites only mention one study that supports the belief of berberine’s effectiveness in treating diabetes, but only one study is not adequate to conclude this belief.

In Published Scientific Literature

        Since “type 1 diabetes is caused by T cell-mediated destruction of beta cells and severe islet inflammation,” the researchers believed that berberine could help treat “type 1 diabetes through its immune regulation properties” (Cui et al., 2009, p. 28420). Sixteen 11-week-old female NOD (non-obese diabetic) mice were treated with either phosphate-buffered saline (PBS) or berberine orally every day for 2 weeks, and they were monitored for 33 weeks to see if they developed diabetes (Cui et al., 2009). “Nonfasting blood glucose was measured in the tail vein every week…with a glucose meter throughout the study, and mice were considered diabetic when the blood glucose level exceeded 250 mg/dl. The nonfasting blood glucose level of all mice was below 250 mg/dl before starting the study” (Cui et al., 2009, p. 28421). All the mice in the PBS group became diabetic, while only 50% of the mice in the berberine group became diabetic (Cui et al., 2009). From the data, it can be concluded that berberine prevented the progression of type 1 diabetes in half of the NOD mice. Even though the sample size is small, the conclusions are reliable because the replicates had very little intrinsic variation as they were all females who were genetically engineered to be NOD.

        Another study was conducted that tested the usefulness and safety of berberine in treating patients with type 2 diabetes and dyslipidemia, which is “elevation of plasma cholesterol, triglycerides (TGs), or both, or a low high density lipoprotein level that contributes to the development of atherosclerosis” ( One hundred sixteen patients with type 2 diabetes and dyslipidemia were randomly placed into two groups: one that received berberine daily and another that received the placebo (Zhang et al., 2008). The patients were given berberine or placebo for three months, and when “compared with subjects who received [the] placebo, those receiving berberine had a significant improvement in fasting plasma glucose and 2-h OGTT plasma glucose, HbA1c, triglyceride, total cholesterol, and LDL-c” (Zhang et al., 2008, p. 2561). Additionally, there was a greater reduction in the body mass index of the berberine group compared to the placebo group after three months. To make sure the study was not harming the patients, “safety parameters including renal and hepatic function, serum electrolytes, blood counts, and urinary analysis were assessed” throughout the study (Zhang et al., 2008, p. 2563). Self-reported side effects were recorded, but there were no serious effects. Although mild to moderate constipation occurred in both groups, the rate at which constipation occurred did not differ significantly (Zhang et al., 2008). This study’s conclusion that berberine is an effective and safe way to treat type 2 diabetes and dyslipidemia is dependable because of the following: the sample size is large (n=116); the study was a double blind trial with a placebo; the patients were from multiple centers; and the patients were screened before they could participate in the study to decrease variation and prevent the possible skewing of data by a small number of patients who have severe diabetes.

        Similarly, a third study wanted to investigate the effects of berberine on diabetes, specifically type 2, and its influence on insulin secretion. Fifty-one out of sixty healthy male Wistar rats were randomly selected and IV injected with streptozotocin or STZ (Leng, Lu, & Xu, 2004). STZ is an anticancer drug that damages white blood cells, and consequently, suppresses the immune system ( Two weeks later, there were forty four impaired glucose tolerance (IGT) rats, which were randomly divided into four groups: the low dose berberine group, the high dose berberine group, the metformin group, and the control group. The nine rats that were not injected with STZ served as the normal group (Leng et al., 2004). “After rats were treated for 4 weeks, oral glucose tolerance was determined, and for 8 weeks, the fasting blood glucose, insulin, lipid series were determined” (Leng et al., 2004, p. 496). The levels of fasting blood glucose, triglycerides, total cholesterol, free fatty acid, and apolipoprotein B were reduced significantly in the groups treated with berberine compared to the control group (Leng et al., 2004). In conclusion, berberine has anti-diabetic effects by lowering blood glucose levels and altering lipids, and the design of the study (with five groups) and a relatively large sample size increases the validity of this study.

        “Berberine can improve insulin resistance, lower blood glucose, and regulate lipid metabolism disorders which cause endothelial dysfunction, leading to vascular complications of type 2 diabetes mellitus” (Wang et al., 2009, p. 131). Thus, the goal of the study was to examine “the effects of berberine on endothelial dysfunction of aortas in type 2 diabetes mellitus rats and its mechanism” (Wang et al., 2009, p. 131). Six-week old Wistar rats were randomly divided into four groups: diabetic rats, control rats, diabetic rats treated with berberine, and control rats treated with berberine. The body weight did not significantly differ among the four groups, and the data indicated that “berberine treatment significantly decreased fasting blood glucose and triglyceride levels compared with untreated diabetic groups” (Wang et al., 2009, p. 133). Even though the sample size of the study was not given, it is mentioned that the rats were all “housed in an environmentally controlled breeding room,” (Wang et al., 2009, p.132) which controls for variations that may have potentially resulted because of the environment. Despite not mentioning the sample size, the conclusions of this study are valid because the results were consistent with similar experiments that were conducted previously.

Summary and Conclusion

Both the information on the World Wide Web and the published scientific studies support the fact that berberine is useful in treating diabetes. Most of the websites on the World Wide Web only mentioned berberine’s efficacy in ameliorating type 2 diabetes. However, according to published scientific literature, berberine is useful for remedying both types of diabetes as well as other disorders associated with diabetes, such as dyslipidemia. Berberine is usually taken orally, even by the mice in the studies, and has few side effects. As a consequence, current research supports the ancient Chinese’s belief that berberine is an effective way to treat diabetes. Yet, since only a small number of clinical trials involving berberine have been conducted, one should be cautious about taking berberine until more clinical studies are carried out.



Cui, G., Qin, X., Zhang, Y., Gong, Z., Ge, B., & Zang, Y. Q. (2009). Berberine differentially modulates the activities of Erk, p38 MAPK and JNK to suppress Th17 and Th1 T cell differentiation in type 1 diabetic mice. The Journal of Biological Chemistry, 284, 28420-28429.

Leng, S. H., Lu, F. E., & Xu, L. J. (2004). Therapeutic effects of berberine in impaired glucose tolerance rats and its influence on insulin secretion. Acta Pharmacologica Sinica, 25(4), 496-502.

Straub, R. O. (2006). Health psychology: A biopsychosocial approach. New York: Worth.

Wang, C., Li, J., Lv, X., Zhang, M., Song, Y., Chen, L., & Liu, Y. (2009). Ameliorative effect of berberine on endothelial dysfunction in diabetic rats induced by high-fat diet and streptozotocin. European Journal of Pharmacology, 620(1-3), 131-137.

Zhang, Y., Li, X., Zou, D., Liu, W., Yang, J., Zhu, N., Huo, Li., Wang, M., Hong, J., Wu, P., Ren, G., & Ning, G. (2008). Treatment of type 2 diabetes and dyslipidemia with the natural plant alkaloid berberine. The Journal of Clinical Endocrinology and Metabolism, 93(7), 2559-2565.




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