Berberine Side Effects: Interactions, Kidneys, Liver and Who Should Avoid It

The most common berberine side effects are digestive: nausea, stomach cramps, bloating, constipation and diarrhea. They are usually mild and often ease when you take it with meals or split the dose. The more important safety points are less obvious. Berberine changes how your liver processes many medicines, it can add to the effect of blood sugar medicines, and it is not considered safe during pregnancy, while breastfeeding or for infants. This guide covers what studies found, kidneys and liver, interactions and who should skip berberine or check with a clinician first.

It is educational, not medical advice.

Key Takeaways

• Digestive side effects are the most common: in one 3-month trial at 500 mg three times a day, about a third of people had temporary stomach or bowel symptoms.
• It interacts with medicines: two weeks of berberine reduced the activity of three liver enzymes (CYP2D6, CYP2C9 and CYP3A4) that clear many common drugs.
• It adds to blood sugar medicines: berberine lowers blood sugar, so taking it with diabetes medicine can push levels too low.
• Not for pregnancy, breastfeeding or infants: the NIH says berberine has been linked to a harmful buildup of bilirubin in infants.
• Kidneys and liver: trials in adults have not reported kidney or liver damage, but people with kidney or liver disease should ask their doctor first.

Berberine Side Effects at a Glance

Most adults tolerate berberine well. Side effects in studies are mainly digestive, and trials have not linked it to liver or kidney damage; one 3-month trial saw none in any patient. The main liver point is about medicines: berberine slows liver enzymes that clear many common drugs.

How often	What it includes	What to know
Common	Nausea, stomach cramps, bloating, gas, constipation, diarrhea	Usually mild and temporary. Taking it with meals, starting low and splitting the dose often helps.
Less common	Rash, swelling or trouble breathing; signs of low blood sugar such as shakiness, sweating or dizziness	Stop and get help. Low blood sugar is mainly a concern alongside blood sugar medicine.
Liver and kidneys	No liver or kidney damage reported in trials	It slows liver enzymes (CYP2D6, CYP2C9, CYP3A4) that clear many medicines.
Check with a clinician first	Blood sugar, blood pressure, blood thinner or transplant medicines (such as cyclosporine); any daily prescription; liver or kidney disease; upcoming surgery	Ask your doctor or pharmacist before starting.
Skip it	Pregnancy, breastfeeding, infants	Do not take it.

Is Berberine Safe?

Berberine is a yellow compound found in plants such as goldenseal, barberry, Oregon grape and Chinese goldthread, and it has a long history in traditional medicine. Today it is sold as a supplement, usually as berberine HCl. You can read more about it on our berberine ingredient page.

For most healthy adults, berberine is well tolerated in the short term. The National Center for Complementary and Integrative Health (NCCIH) notes that the side effects reported in research studies are mainly digestive, such as nausea, abdominal pain, bloating, constipation or diarrhea (NCCIH, 2023). A 2025 review of randomized, placebo-controlled trials described berberine as having a favorable safety profile (Liu, 2025).

Most of that research lasted weeks to months, not years, and it was done with berberine on its own, not mixed with other medicines. That is why the interaction and pregnancy warnings below matter more than the common side effects.

Study	Who and how much	What was reported about safety
Yin, 2008 (3 months)	Adults with blood sugar problems; 500 mg three times a day	34.5 percent had temporary digestive side effects; no liver or kidney damage was seen in any patient.
Guo, 2012 (2 weeks)	Healthy men; 300 mg three times a day	Lower activity of liver enzymes CYP2D6, CYP2C9 and CYP3A4; the authors advised considering drug interactions.
Liu, 2025 (review)	Randomized placebo-controlled trials	Favorable safety profile overall.
NCCIH (2023)	Summary of research	Mainly digestive side effects; possible medicine interactions; likely unsafe for infants and possibly in pregnancy and breastfeeding.

The Most Common Berberine Side Effects

• Constipation.
• Diarrhea or loose stools.
• Stomach cramps, bloating and gas.
• Nausea.

In the 3-month trial above, 20 people (34.5 percent) had digestive side effects, and they were described as transient (Yin, 2008). That trial used 1,500 mg a day, a higher amount than many people take.

How to Reduce Stomach Side Effects

• Take it with or just before meals, not on an empty stomach.
• Start low and increase slowly.
• Split the dose across meals instead of taking it all at once.
• Drink water and eat fiber if constipation is a problem.

Our guide to berberine phytosome vs HCl explains how the form of berberine affects absorption, and how long berberine takes to work covers timing with meals.

Berberine and Medications

This is the most important safety point. In a crossover study in healthy men, two weeks of berberine at 300 mg three times a day lowered the activity of three liver enzymes, CYP2D6, CYP2C9 and CYP3A4. These enzymes break down a large share of prescription drugs, so berberine can raise the levels of some medicines in the blood. The authors concluded that drug interactions should be considered when berberine is used (Guo, 2012).

NCCIH also notes that berberine has been shown to interact with cyclosporine, a transplant medicine (NCCIH, 2023), and that goldenseal, a berberine-containing herb, lowered levels of metformin by about 25 percent in healthy adults (NCCIH, 2025).

Talk with your doctor or pharmacist before taking berberine if you take:

• Diabetes or blood sugar medicines, including insulin, metformin or GLP-1 medicines. Together they can lower blood sugar too far.
• Blood thinners or other medicines with a narrow safe range.
• Blood pressure medicines.
• Transplant or immune-suppressing medicines, such as cyclosporine.
• Any daily prescription medicine, since many are cleared by the enzymes berberine affects.

If you take a GLP-1 medicine, our guide to berberine and semaglutide covers that combination in more detail.

Berberine and Low Blood Sugar

In the 3-month trial in adults with blood sugar problems, berberine lowered blood sugar by a similar amount to metformin at the same dose (Yin, 2008). If you already take blood sugar medicine, the two together can push your levels too low.

Signs of low blood sugar include shakiness, sweating, a racing heart, sudden hunger, dizziness and confusion. If you notice them, eat or drink something with sugar and contact your clinician.

If you drink, our guide to berberine and alcohol explains how the two overlap on blood sugar and when to skip a dose. If you are also considering chromium, our guide to chromium picolinate vs berberine explains how the two differ.

Is Berberine Bad for Your Kidneys?

In adults without kidney disease, trials have not shown kidney harm. In the 3-month trial, no kidney damage was seen in any patient (Yin, 2008). Animal studies have mostly looked at whether berberine protects the kidneys rather than harms them (Xu, 2025), but animal results do not tell us how it behaves in people with kidney disease.

If you have kidney disease, reduced kidney function, or take several medicines for it, ask your doctor before using berberine, both because of the kidneys themselves and because of the medicine interactions above.

Is Berberine Safe for Your Liver?

In trials, berberine has not been linked to liver damage, and the 3-month trial reported no liver damage in any patient (Yin, 2008). Because berberine works through the same liver enzymes that clear many medicines, people with liver disease or who take medicines processed by the liver should talk with their doctor first.

Pregnancy, Breastfeeding and Infants

Do not take berberine if you are pregnant or breastfeeding, and never give it to infants. NCCIH says exposure to berberine has been linked to a harmful buildup of bilirubin in infants, which can cause brain damage, and that it may also be unsafe during pregnancy or breastfeeding because of possible effects on the fetus or infant (NCCIH, 2023). Laboratory research found that berberine can push bilirubin off the protein that normally carries it in the blood (Chan, 1993).

For more on women's health questions, see berberine for women.

Who Should Avoid Berberine

• Pregnancy, breastfeeding or trying to conceive.
• Infants and children.
• Anyone taking diabetes or blood sugar medicine, unless a clinician is monitoring you.
• Anyone taking prescription medicines cleared by the liver, including transplant medicines and blood thinners.
• Kidney or liver disease.
• Low blood pressure or low blood sugar episodes.
• Upcoming surgery. Tell your surgical team, since berberine affects blood sugar and medicine levels.

For what berberine does and what trials measured, see our guide to berberine benefits.

If a berberine blend also contains bitter melon, our guide to bitter melon supplements covers its own list of who should skip it.

How to Take Berberine More Safely

• Check with your clinician first if you take any prescription medicine.
• Take it with or 15 to 30 minutes before meals.
• Follow the label. The 3-month trial above used 500 mg three times a day. Our Berberine Blend provides 500 mg of berberine per 2-capsule serving, with Ceylon cinnamon, bitter melon and chromium; the label suggests 1 to 2 capsules, 1 to 3 times daily, 15 to 30 minutes before meals.
• Choose third-party tested ingredients and a label that states the exact berberine amount.
• Stop and get help if you notice signs of low blood sugar, a rash, swelling or trouble breathing.

Berberine is often paired with Ceylon cinnamon; see berberine and Ceylon cinnamon together and our Ceylon cinnamon ingredient page. For the bigger picture, see metabolic health and energy balance, and to compare products, our berberine buyer’s guide. Cinnamon is also made into a simple drink; see cinnamon water for how to make it and how much is safe. For meal timing and how to split doses, see our guide to the best time to take berberine.

Frequently Asked Questions

What cannot be taken with berberine?

Be careful combining berberine with diabetes or blood sugar medicines, cyclosporine and other transplant medicines, blood thinners, and other prescription drugs cleared by the liver enzymes CYP2D6, CYP2C9 and CYP3A4. Ask your doctor or pharmacist before combining them.

What happens when you take berberine every day?

Most trials gave berberine daily for weeks to a few months. The most common effects were digestive, such as constipation, diarrhea or cramps, which often ease over time or with meals. It also lowers blood sugar, which matters if you take medicine for it.

Is berberine bad for your kidneys?

Trials in adults have not reported kidney damage, and one 3-month trial saw none in any patient. There are no good studies in people with kidney disease, so check with your doctor first if you have it.

Is berberine hard on the liver?

Trials have not linked berberine to liver damage. It does slow some liver enzymes that clear medicines, so talk with your doctor if you have liver disease or take prescription drugs.

What are the side effects of berberine on the liver?

None have been reported in trials: a 3-month trial saw no liver damage in any patient, and a 2025 review of placebo-controlled trials described a favorable safety profile. Berberine does slow liver enzymes that clear many drugs, so check with your clinician first if you have liver disease or take prescription medicines.

Are berberine HCl side effects different?

Berberine is usually sold as berberine HCl, so the side effects in this guide are the ones to expect: mainly digestive, and often eased by taking it with meals. Our guide to dihydroberberine vs berberine compares another form.

Is it safe to take berberine long term?

Most research gave berberine daily for weeks to a few months, and most adults tolerated it well. For longer use, follow the label, check with your clinician if you take prescription medicine, and choose third-party tested ingredients; our guide to what third-party tested means shows how to check.

Why don't some doctors recommend berberine?

Mainly because of medicine interactions, the risk of low blood sugar when combined with diabetes medicine, limited long-term data, and variable quality between supplement brands. A doctor who knows your medicines can tell you whether it fits.

Can berberine cause low blood sugar?

The main risk is combining it with insulin, metformin or other blood sugar medicines, since the effects can add up and push levels too low.

Is berberine safe during pregnancy?

No. NCCIH says berberine is likely unsafe for infants and may be unsafe during pregnancy and breastfeeding because of a possible buildup of bilirubin in the baby.

Do berberine side effects go away?

Digestive side effects are often temporary. Taking berberine with meals, starting with a smaller dose and splitting it across the day usually helps.

Sources

• National Center for Complementary and Integrative Health. Berberine and Weight Loss: What You Need To Know. Updated November 2023. NCCIH
• National Center for Complementary and Integrative Health. Goldenseal. Updated February 2025. NCCIH
• Yin J, et al. Efficacy of berberine in patients with type 2 diabetes mellitus. Metabolism. 2008. PubMed 18442638
• Guo Y, et al. Repeated administration of berberine inhibits cytochromes P450 in humans. Eur J Clin Pharmacol. 2012. PubMed 21870106
• Liu D, et al. Efficacy and safety of berberine on the components of metabolic syndrome: a systematic review and meta-analysis of randomized placebo-controlled trials. Front Pharmacol. 2025. PubMed 40740996
• Xu W, et al. The therapeutic effect of berberine on rodent models of kidney injury: a systematic review and meta-analysis. BMC Nephrol. 2025. PubMed 40597833
• Chan E. Displacement of bilirubin from albumin by berberine. Biol Neonate. 1993. PubMed 8513024

These statements have not been evaluated by the Food and Drug Administration. This content is for education and is not medical advice. Our products are not intended to diagnose, treat, cure or prevent any disease. Talk with a healthcare provider before starting a new supplement if you are pregnant, breastfeeding or taking medication.