Berberine is an alkaloid found in many plants, but most notably in goldenseal (Hydrastis canadensis), barberry (Berberis vulgaris), Oregon grape (Berberis aquifolium), and goldthread (Coptis chinensis). These plants have a long history of use in a long list of health conditions. Many double-blind clinical studies with isolated berberine have shown significant success in the treatment of acute diarrhea, the irritable bowel syndrome, type 2 diabetes, high blood pressure, elevated blood lipids, Alzheimer’s disease, and cancer.

Berberine in Acute Diarrhea:

Berberine has been found effective against diarrheas caused by a number of different types of organisms including E. coli (traveler’s diarrhea), Shigella dysenteriae (shigellosis), Salmonella paratyphi (food poisoning), B. Klebsiella, Giardia lamblia (giardiasis), Entamoeba histolytica (amebiasis), and Vibrio cholerae (cholera).

These results indicate berberine appears to be effective in treating the majority of common gastrointestinal infections with results comparable to standard antibiotics in most cases. In fact, results were better in several studies. The advantage of berberine over conventional antibiotics is that it exerts selective antimicrobial action as it targets a wide range of disease-causing organisms including Candida albicans, yet exerts no action against health promoting bacterial species such as Lactobacilli and Bifidobacter species.

Berberine in SIBO and IBS:

Berberine has been shown to be effects in the irritable bowel syndrome (IBS) and several preliminary studies suggest berberine may also be effective in small intestinal overgrowth (SIBO).

IBS is associated with some combination of:

  • Abdominal pain or distension
  • Altered bowel function, constipation, or diarrhea
  • Hypersecretion of colonic mucus
  • Dyspeptic symptoms (flatulence, nausea, anorexia)
  • Varying degrees of anxiety or depression

With SIBO, there are often other associated symptoms including:

  • Brain “fogginess”
  • Fatigue
  • Joint pain
  • Skin issues: acne, eczema, rashes, or rosacea
  • Weight loss

In a 2015 double-blind study, 196 patients with diarrhea-predominant IBS were randomized to receive either berberine (200 mg) or a placebo (vitamin C 200 mg) twice a day for eight weeks. The berberine group, but not the placebo group, reported significant improvement in diarrhea and less urgency and frequency of defecation. The berberine group also experienced a 64.6% reduction in abdominal pain compared with initial scores at the end of the score. Berberine significantly decreased the overall IBS symptom score, anxiety score, and depression score. Lastly, and not surprisingly, berberine was associated with an increased quality of life score in patients while no such change was seen in the placebo group.

Several studies suggest berberine may be effective in SIBO. In addition to the benefits noted above in IBS, berberine clearly inhibits bacterial and yeast overgrowth in the small intestine, in animal models berberine improves intestinal motility.11 This action is another key goal in patients with SIBO (and IBS).

Berberine’s Effects on Blood Sugar, Lipids, and Hypertension:

Berberine has been extensively studied in clinical trials for lowering blood sugar, lipids, and hypertension. Recently, the Journal of Ethnopharmacology published a detailed review of the 27 clinical studies with berberine in these disorders that provided clear answer questions on its safety and efficacy.

Results showed quite convincingly that in the treatment of type 2 diabetes mellitus, berberine (500 mg two to three times daily) along with lifestyle intervention lowered the level of fasting blood sugar levels, after-meal blood sugar levels and glycosylated hemoglobin (HbA1c) more than lifestyle intervention alone or placebo. When berberine was compared to oral hypoglycemic drugs used in type 2 diabetes like metformin, glipizide and rosiglitazone, there was no statistical significance between the treatment of berberine and these drugs. In other words, the clinical results seen with berberine are on par with the drugs, but with no significant side effects.

The same sort of comparative results seen in type 2 diabetes were found in the treatment of elevated blood lipids (cholesterol and triglycerides) and high blood pressure. In regards to its effects on blood lipids not only does it lower total and LDL cholesterol, unlike statins, berberine also lowers blood triglycerides and raises beneficial HDL cholesterol. Berberine has also been shown to lower apolipoprotein B by 13-15%, which is another very important risk factor to reduce heart disease. Studies also supported that berberine combined with conventional drugs in these conditions is safe and can produce better results than the drugs used alone. Side effects with berberine occurred at much lower rates and were milder than prescription drugs. Side effects were seen mainly at higher doses (e.g., 500 mg three times a day) and included such as nausea, diarrhea, constipation, abdominal distension, and abdominal pain.

Berberine produces these metabolic effects on through various physiological mechanisms. Most of its actions involve AMP-activated protein kinase (AMPK) – an enzyme involved in regulating the body’s energy levels. By targeting this pathway, berberine induces the uptake of glucose into cells, where it is converted into energy. Activating AMPK is also key to berberine’s function in regulating blood lipids, such as LDL cholesterol, total cholesterol and triglycerides. This enzyme acts as a master switch, regulating energy production and storage as well as lipid metabolism. It helps burn fatty acids within cells, stabilize the receptors for LDL cholesterol and inhibit the formation of lipids by the liver.

It also promotes insulin sensitivity by increasing the number and activity of available insulin receptors. This allows the same concentration of insulin to be more effective at moving glucose out of the bloodstream. Using insulin more efficiently is a foundation for successfully supporting healthy blood sugar levels.

Berberine in Weight Loss:

Berberine has also been examined as a weight loss aid in two double-blind clinical trials.  In one study, 37 men and women with metabolic syndrome were given 300 mg of berberine three times per day for three months. The body mass index (BMI) levels dropped from 31.5 to 27.4. In another study, 500 mg of berberine three times per day caused an average of 5 pounds of weight loss over a 12-week period. There were also improvements in insulin sensitivity and fat-regulating hormones.

Recommended adult dose

One 500 mg capsule before meals with a glass of water two to three times daily.

Side Effects:

Berberine is generally well-tolerated at recommended dosage levels. In clinical studies at 500 mg two to three times daily side effects are generally mild and may include nausea, diarrhea, constipation, abdominal distension, and/or abdominal pain.

Berberine and berberine-containing plants are not recommended for use during pregnancy.


Berberine may interfere with the absorption of tetracycline and related antibiotics. Berberine produces significant inhibition of CYP3A enzymes in humans. Because most drugs are metabolized by these enzymes, berberine may decrease the clearance of many medications thereby potentiating their effect.

Berberine-containing plants may enhance the effects of oral hypoglycemic drugs through its multitude of anti-diabetic effects. People on oral hypoglycemic drugs should monitor blood glucose levels if taking berberine. Adjustment of drug dosage may be required.


Like all supplements, keep out of reach of children.