Avoided in individuals with a known allergy or hypersensitivity to berberine, to plants that contain berberine [Hydrastis canadensis (goldenseal), Coptis chinensis (coptis or goldenthread), Berberis aquifolium (Oregon grape), Berberis vulgaris (barberry), and Berberis aristata (tree turmeric)], or to members of the Berberidaceae family. Allergic reactions have been reported, with symptoms of vomiting, itching, and a feeling of faintness.
Side Effects and Warnings
Berberine has been reported to cause nausea, vomiting, hypertension (high blood pressure), respiratory failure and paresthesias (abnormal sensations such as numbness or tingling); however, clinical evidence of such adverse effects is not prominent in the literature. Rare adverse effects including headache, skin irritation, facial flushing, headache, bradycardia (slowed heart rate) have also been reported with the use of berberine. Use cautiously when taking berberine for longer than eight weeks due to theoretical changes in bacterial gut flora.
Use cautiously in individuals with diabetes, as both human and animal studies indicate that berberine may decrease blood sugar levels. Also use cautiously in individuals with hypotension (low blood pressure), as berberine may have antihypertensive effects.
Patients with cardiovascular disease should also use caution as berberine has been associated with the development of ventricular arrhythmias in subjects with congestive heart failure.
Although not well studied in humans, berberine may also theoretically cause delays in small intestinal transit time or increase the risk of bleeding.
Berberine may cause abortion, eye or kidney irritation, nephritis (inflamed kidneys), dyspnea (difficulty breathing), flu-like symptoms, giddiness, lethargy, or liver toxicity.
Patients with leukopenia (abnormally low white blood cell count) should use cautiously due to the potential for development of leukopenia symptoms.
When injected under the skin, berberine may cause hyperpigmentation in the arm. Use berberine cautiously in individuals with high exposure to sunlight or artificial light due to potential for adverse phototoxic reactions.
Avoid in newborns due to potential for increase in free bilirubin, jaundice, and development of kernicterus (brain damage caused by severe newborn jaundice). Use berberine cautiously in children due to a lack of safety information.
Pregnancy and Breastfeeding
Berberine is not recommended in pregnant or breastfeeding women due to a lack of available scientific evidence. Although not well studied in humans, berberine has been suggested to have anti-fertility, abortifacient (abortion inducing), and uterine stimulant activity.
Berberine may cause kernicterus (brain damage) when used in newborn jaundiced babies, such as bilirubin encephalopathy (degenerative brain disease).
Adults (18 years and older)
A wide range of doses has been studied for berberine, although no dose has been proven effective. Berberine is possibly safe when taken by mouth in doses up to 2 grams daily for eight weeks. For hypercholesterolemia (high cholesterol), 0.5 gram of berberine twice daily for three months has been used. For infectious diarrhea, berberine sulfate 400 milligrams as a single dose has been used. For thrombocytopenia, berberine bisulfate 5 milligrams, three times daily (20 minutes before meals) for 15 days has been used.
As an injection into the vein, berberine has been infused at a rate of 0.2 milligrams/kilogram per minute for 30 minutes. Injections should only be given under the supervision of a qualified healthcare professional, including a pharmacist.
For trachoma, 0.2% berberine eye drops have been studied for eight weeks.
Children (younger than 18 years)
There is no proven effective dose for berberine in children. Nonetheless, berberine is possibly safe when used in otherwise healthy children, as young as two months, at recommended doses for treatment of diarrhea up to six days.
Interactions with Drugs
Berberine may counter or prevent irregular heartbeat. Caution is advised when taking berberine with other agents that alter heart rate.
Berberine may decrease the efficacy of tetracycline; in theory, berberine may decrease the efficacy of other agents with antibacterial activity.
Berberine bisulfate may stimulate platelet formation, and berberine may have an antiheparin action. Thus, berberine may interact with certain drugs that increase the risk of bleeding, and reduce their effectiveness. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin®) or heparin, anti-platelet drugs such as clopidogrel (Plavix®), and non-steroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®). However, berberine may be hepatoprotective (liver protective) when administered before toxic doses of acetaminophen.
Berberine may lower blood sugar levels. Caution is advised when using medications that may also lower blood sugar. Patients taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
Berberine may decrease total and LDL cholesterol, as well as triglycerides. Caution is advised in patients taking any cholesterol-lowering agents.
There may be additive hypotensive (blood pressure lowering) effects and bradycardia (slowed heart rate) when combining berberine with agents that lower blood pressure. Caution is advised.
Berberine may modulate the expression and function of PGP-170 in hepatoma cells. In theory, berberine may interact with antineoplastic agents.
Berberine and berberine sulfate have anti-inflammatory effects and may interact with COX-2 inhibitors. COX-2 inhibitor drugs include celecoxib (Celebrex®) and rofecoxib (Vioxx®).
Berberine may elevate the blood concentration of cyclosporin A. Caution is advised.
Berberine may interfere with the way the body processes certain drugs using the liver's "cytochrome P450" enzyme system. As a result, the levels of these drugs may be increased in the blood, and may cause increased effects or potentially serious adverse reactions. Patients using any medications should check the package insert, and speak with a qualified healthcare professional, including a pharmacist, about possible interactions.
Although not well studied in humans, there may be a potential for synergism between berberine chloride and fluconazole. Berberine and L-phenylephrine may have additive effects when administered concurrently. Furthermore, berberine may reverse the secretory properties of neostigmine (Prostigmin®).
Berberine and 1,3-bis (2-chloroethyl)-1-nitosurea (BCNU) may have additive effects.
Berberine may increase sensitization to acetylcholine's hypotensive (blood pressure lowering) effects.
P-glycoprotein may contribute to the poor intestinal absorption of berberine.
It is been purported that berberine may have sedative effects. Although human study is lacking, caution is advised.
Berberine may competitively inhibit the binding of yohimbine to platelets. Patients taking yohimbine should consult with a qualified healthcare professional, including a pharmacist, to check for interactions.
Interactions with Herbs and Dietary Supplements
Berberine may counter or prevent irregular heartbeat. Caution is advised when taking berberine with other herbs that alter heart rate.
Berberine may decrease the efficacy of tetracycline; thus, in theory, berberine may decrease the efficacy of herbs with antibacterial activity.
Berberine bisulfate may stimulate platelet formation, and berberine may have an antiheparin action. Thus, berberine may interact with certain herbs that increase the risk of bleeding and reduce their effectiveness. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.
There may be additive hypotensive (blood pressure lowering) effects and bradycardia (slowed heart rate) when combining berberine with herbs that lower blood pressure. Caution is advised.
Berberine may lower blood sugar levels. Caution is advised when using herbs or supplements that may also lower blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.
Berberine may decrease total and LDL cholesterol, as well as triglycerides. Caution is advised in patients taking herbs or supplements with cholesterol-lowering effects, such as red yeast rice.
Concomitant use of berberine-containing herbs may increase the risk of berberine toxicity. Berberine-containing herbs include: bloodroot, goldenseal, celandine, Chinese goldthread, goldthread, Oregon grape (Mahonia species), amur cork tree, and Chinese corktree.
Berberine may interfere with the way the body processes certain herbs or supplements using the liver's "cytochrome P450" enzyme system. As a result, the levels of other herbs or supplements may become too high in the blood. It may also alter the effects that other herbs or supplements possibly have on the P450 system.
Although not well studied in humans, berberine may have sedative effects.
Based on clinical study, tyramine-containing foods, such as wine, cheese, and chocolate, may have an interaction with berberine due to berberine's effect on decreasing levels of tyramine.
Berberine may competitively inhibit the binding of yohimbine to platelets. In addition, due to the antifertililty properties of berberine, use of yohimbe for fertility may not be effective.
Berberine may decrease the metabolism of vitamin B; therefore, the concomitant use of berberine with vitamin B should be avoided.