In the Spotlight: Berberine

by Amylee Amos PhD, RDN, IFMCPNutrition
Berberine plant on hanging on a tree

Berberine is a supplement often recommended for individuals following the Bredesen Protocol, specifically for those who have or are at risk of developing subtype 1.5 (glycotoxic) Alzheimer’s disease.

What is berberine?

Berberine is an alkaloid that is extracted from the roots of various plants used commonly in Chinese medicine, including goldenseal, European barberry, and phellodendron (1). Bitter in taste and bright yellow in color, berberine has been used for conditions including diabetes, hyperlipidemia, hypertension, polycystic ovarian syndrome and more. Though many of the purported uses of berberine have inconsistent results in research, the overall consistency of research results in berberine’s ability to lower blood glucose is very high (2). Additionally, berberine is often used as a selective antibacterial agent, as it has powerful antimicrobial properties.

What does the research show?

Taking 500mg of berberine two to three times per day for two to three months reduced biomarkers of diabetes including fasting blood glucose, post prandial blood glucose, and hemoglobin A1c (3). The effect of berberine was comparable to diabetes medications including metformin and rosiglitazone. In a meta analysis of berberine, researchers found that two to three divided doses totaling 0.9-1.5 grams of berberine per day along with glucose lowering lifestyle interventions reduced fasting blood glucose by 16 milligrams per deciliter, reduced post prandial blood glucose by 34 milligrams per deciliter, and reduced hemoglobin A1c by 0.7% compared with blood glucose lowering lifestyle interventions alone (1). Berberine also appears to lower fasting insulin levels, another important biomarker in measuring insulin resistance and the metabolic dysfunction that leads to diabetes (4). The mechanism through which berberine is able to increase insulin sensitivity seems to be though its activation of adenosine monophosphate activated protein kinase (AMPK) and its inhibition of protein tyrosine phosphatase 1B (PTP1B) (5). Secondary mechanisms that may explain how berberine alleviates the severity of diabetes signs and symptoms and improves metabolic syndrome include its ability to lower the systemic inflammatory response of the body (6).

Should I take berberine?

While berberine appears to be an effective herbal supplement to improve and optimize blood glucose in those with diabetes and prediabetes, its use as a therapeutic intervention is not without limitations. Berberine supplementation may have severe interactions with certain classes of medications, which must be considered before starting to take this supplement. Berberine has moderate interactions with antiplatelet and anticoagulant drugs, anti-diabetes drugs, antihypertensive drugs, central nervous system depressants, and cytochrome P450 substrates, among other classes of pharmaceuticals. Berberine has a major potential for adverse reaction when combined with cyclosporine (3). Thus, you should carefully discuss taking berberine with your doctor and dietitian before starting this supplement.


  1. Lan, J., Zhao, Y., Dong, F., Yan, Z., Zheng, W., Fan, J., & Sun, G. (2015). Meta-analysis of the effect and safety of berberine in the treatment of type 2 diabetes mellitus, hyperlipemia and hypertension. Journal of Ethnopharmacology, 161, 69-81. doi: 10.1016/j.jep.2014.09.049
  2. Patel, K. (2020, November). Berberine.
  3. Natural Medicines (2021, January). Berberine.,-herbs-supplements/professional.aspx?productid=1126
  4. Yin, J., Xing, H., & Ye, J. (2008). Efficacy of berberine in patients with type 2 diabetes mellitus. Metabolism: clinical and experimental,57(5), 712–717.
  5. Yin, J., Ye, J., & Jia, W. (2012). Effects and mechanisms of berberine in diabetes treatment ,Acta Pharmaceutica Sinica B, 2(4), 327-334.
  6. Cao, C., & Su, M. (2019). Effects of berberine on glucose-lipid metabolism, inflammatory factors and insulin resistance in patients with metabolic syndrome.E xperimental and therapeutic medicine,17(4), 3009–3014.