Last updated: October 2026
Berberine is a yellow plant compound found in barberry, goldenseal and Oregon grape. Trials suggest it can modestly lower blood sugar and cholesterol, but weight loss is small, around 1 to 2kg on average, so it isn’t “nature’s Ozempic”. It interacts with many medicines and should be avoided in pregnancy. Speak to a GP or pharmacist first.
Below: the research, berberine vs metformin and weight loss injections, study doses, side effects and interactions.
The short version: berberine isn’t a treatment for diabetes, high cholesterol or obesity, and never a substitute for prescribed medicine. If you take any regular medicine, check with your GP or pharmacist first, and never stop or swap a prescribed medicine for a supplement.
What is berberine?
Berberine is an alkaloid, a natural plant compound, with a deep yellow colour that has long been used as a dye. It’s found in several plants, including:
- barberry (Berberis), the shrub in our photo
- goldenseal
- Oregon grape
- Chinese goldthread (Coptis) and tree turmeric
These plants have a long history in traditional Chinese medicine and Ayurveda. Today berberine is sold as a purified supplement, mostly studied for diabetes and cholesterol.
Berberine vs berberine HCl: berberine HCl (hydrochloride) is a common salt form, used in many trials, including the IBS trial below. It’s the same active compound.
Berberine vs dihydroberberine: dihydroberberine is a related form marketed as better absorbed. A 2021 pilot study in just five men found 100mg or 200mg of dihydroberberine gave higher blood berberine levels than 500mg of berberine, but no difference in blood sugar, and one author advised a supplement maker. There’s no good evidence yet that it works better.
What does the evidence show?
Most berberine trials are small, short (usually 4 to 24 weeks) and were run in Asia, mostly China, often in people who already had diabetes or raised cholesterol. Reviewers regularly rate the quality as low. Here’s what the larger reviews found:
| Area | What reviews of trials found | How sure can we be? |
|---|---|---|
| Blood sugar | Across 20 placebo-controlled trials (1,761 people), fasting blood sugar fell by about 0.5 mmol/L and HbA1c (the three-month average) by about 4.5 mmol/mol. Effects were larger in people with diabetes. | Fair, but most trials were small and in Asia. Earlier reviews rated quality as low. |
| Cholesterol | Across 18 placebo-controlled trials (1,788 people), LDL (“bad”) cholesterol fell by about 0.46 mmol/L and triglycerides by about 0.34 mmol/L. HDL rose very slightly. | Fair. The authors call the effects small. |
| Weight | Average weight loss of about 0.9kg (23 trials) to 2.1kg (12 trials), with waist size down by 1 to 1.3cm. | Low. Many studies at high risk of bias. |
| PCOS (PMOS) | Ten trials (713 women) added berberine to standard medicines and reported better ovulation and pregnancy rates. | Low. Needs confirming in better trials. |
| Gut (IBS and SIBO) | One trial of 132 people with diarrhoea-type IBS reported less diarrhoea, tummy pain and urgency over 8 weeks. One unrandomised SIBO study used multi-herb products that contained berberine. | Very low. Too few studies. |
Blood sugar. A 2012 review of 14 trials (1,068 people with type 2 diabetes) found berberine lowered blood sugar more than lifestyle changes alone, and added to diabetes tablets it gave extra lowering. It didn’t beat metformin or other tablets, and the trials were low quality.
Cholesterol. A 2021 review of trials using berberine on its own found similar falls in triglycerides, total cholesterol and LDL. These effects are modest, and berberine isn’t a replacement for a statin.
PCOS (now PMOS) and gut health. Berberine is popular in online “PCOS stacks” alongside inositol. Our guide to inositol compares the two, and what the new PMOS name means explains the condition. For gut symptoms, start with our guides to gut health and supplements for digestion, and see a GP about ongoing diarrhoea or tummy pain.
Berberine for weight loss: is it “nature’s Ozempic”?
No. TikTok made “nature’s Ozempic” famous, but the numbers don’t support it.
- A 2020 review of 12 trials found an average weight loss of about 2kg and a fall in BMI of about half a point.
- A larger 2026 review of 23 trials found an average weight loss of under 1kg (0.88kg), with waist size down by about 1.3cm and no change in waist-to-hip ratio.
- The US National Center for Complementary and Integrative Health (NCCIH) says the evidence is “not conclusive”. Effects were seen mainly above 1g a day for more than 8 weeks, and many studies had a high risk of bias.
By comparison, people in the main trial of semaglutide 2.4mg (the dose used for weight loss) lost an average of 14.9% of their body weight over 68 weeks. In the main tirzepatide trial, average losses were 15% to 21% over 72 weeks. For someone weighing 100kg, that’s roughly 15kg or more, against 1 to 2kg in berberine trials.
If weight is a worry, a GP can talk you through options. We take the same honest look at other popular claims in magnesium and weight loss and CBD and weight loss. Tummy fat in midlife has its own causes: see menopause weight gain and cortisol belly. If cravings are the struggle, our guide to sugar cravings may help.
Berberine vs metformin vs GLP-1 injections
They’re often lumped together online, but they’re very different things. Never use berberine in place of a medicine you’ve been prescribed.
| Berberine | Metformin | GLP-1 injections (semaglutide, tirzepatide) | |
|---|---|---|---|
| What it is | A plant compound sold as a supplement | A diabetes medicine | Weekly injected medicines that mimic gut hormones |
| UK status | Food supplement, not a licensed medicine | Prescription only | Prescription only (NHS or private) |
| Used for | Not approved to treat any condition | Type 2 diabetes, gestational diabetes, PMOS symptoms | Type 2 diabetes and obesity |
| Weight change in trials | About 1 to 2kg on average, low certainty | Prescribed for blood sugar, not as a weight loss medicine | About 15% to 21% of body weight over 68 to 72 weeks |
| Common side effects | Nausea, tummy pain, bloating, constipation, diarrhoea | Nausea, diarrhoea, tummy pain, low vitamin B12 | Nausea, vomiting, constipation, diarrhoea, tiredness |
| Key cautions | Interacts with many medicines; avoid in pregnancy and breastfeeding | Tell your doctor about any supplements | Buy only from a registered pharmacy; tell your doctor about supplements |
Berberine vs metformin: a small 2008 pilot trial in 36 adults with new type 2 diabetes found similar blood sugar lowering with either, at 0.5g three times a day. One pilot doesn’t make them interchangeable, and the 2012 review found berberine no better than diabetes tablets. Taken together, their effects could add up, so ask your GP or pharmacist first. Metformin can also lower vitamin B12 over time.
Berberine with Mounjaro or Wegovy: the NHS says some supplements may not mix well with these medicines, so check with your prescriber first. See also can’t sleep on Mounjaro? and magnesium and Mounjaro.
How much berberine do studies use?
There’s no official recommended amount in the UK. These are the doses used in research, not advice to take them:
| Study area | Doses used in trials |
|---|---|
| Cholesterol (18 trials) | 900mg to 1,500mg a day |
| Type 2 diabetes (2008 pilot) | 500mg three times a day for 3 months |
| Weight (NCCIH summary) | Effects mainly above 1g a day for more than 8 weeks |
| Diarrhoea-type IBS | 400mg a day of berberine HCl, split into two doses, for 8 weeks |
Best time to take berberine: trials usually split the daily amount into two or three doses, and the absorption study above gave doses with breakfast, lunch and dinner. No time of day has been shown to work better. Stomach upset is more common at higher doses.
Berberine patches: these are sold online, but the trials above used tablets or capsules taken by mouth, so they tell us nothing about patches.
Strength and quality vary between brands, and safety beyond about six months hasn’t been well studied.
Side effects
The most common side effects are stomach-related: nausea, tummy pain, bloating, constipation or diarrhoea. Appetite loss and rash have also been reported.
- In the cholesterol review, stomach side effects were reported in 2% to 23% of people taking berberine, against 2% to 15% on a placebo. No serious side effects were reported.
- In the 2008 diabetes study, about a third of people (34.5%) had short-lived stomach side effects.
If you feel shaky, sweaty, confused or very hungry, especially on diabetes medicines, your blood sugar may be too low: stop berberine and get medical advice. Sleepiness after meals is a separate issue; see tired after eating.
Medicine interactions
This is the biggest safety issue with berberine. A 2012 study in healthy men found that two weeks of berberine (300mg three times a day) slowed three liver enzymes, CYP3A4, CYP2D6 and CYP2C9, that break down many common medicines. That can raise the level of a medicine in your blood. Check with a pharmacist if you take:
- Ciclosporin or tacrolimus (transplant medicines). In kidney transplant patients, ciclosporin levels were about 29% higher with berberine than without. A raised tacrolimus level with kidney harm has been reported in a child.
- Diabetes medicines, including metformin, sulfonylureas and insulin. Adding berberine could push blood sugar too low.
- Blood thinners. A 2022 case report described a harmful interaction between berberine and the blood thinner rivaroxaban.
- Some cancer medicines, such as bosutinib.
- Any regular prescription medicine, especially one with a narrow safe range. Your pharmacist can check how it’s broken down.
Always tell your GP, pharmacist or surgeon that you take berberine, as you would any medicine.
Who should avoid berberine
- Pregnancy and breastfeeding. NCCIH says berberine may be unsafe in pregnancy and while breastfeeding because of possible effects on the baby. Memorial Sloan Kettering Cancer Center advises avoiding it, as it may worsen jaundice in newborns or lead to kernicterus, a rare type of brain damage caused by very high bilirubin. Lab research found berberine pushes bilirubin off the protein that normally carries it safely in the blood. We don’t recommend our products during pregnancy or breastfeeding.
- Babies and children. Berberine is likely unsafe for infants. Don’t give it to children or teenagers.
- Anyone on regular medicines (see above), or with a long-term health condition, unless a GP or pharmacist has agreed it.
- Anyone trying to conceive, unless your GP or fertility clinic has agreed it.
Is berberine legal in the UK?
Yes. Berberine is sold in the UK as a food supplement, not a licensed medicine. Food supplements are regulated as food and aren’t meant to treat or prevent disease, so they don’t go through the checks that medicines do.
No health claims are authorised for berberine: it isn’t on the GB nutrition and health claims register. Be wary of any label or advert saying it lowers blood sugar, cholesterol or weight.
Supporting the basics
For blood sugar, cholesterol and weight, the strongest evidence is for the everyday basics: regular meals, fibre, movement, sleep and the treatment your GP recommends. Our guide to magnesium for PCOS looks at one nutrient that’s often low.
We don’t sell berberine. Our Magnesium Glycinate Sleep Complex is a warm evening drink with magnesium bisglycinate and citrate, glycine and L-theanine. Magnesium contributes to the reduction of tiredness and fatigue and to normal psychological function. It isn’t a weight loss or blood sugar product. It’s for adults only, and we don’t recommend our products during pregnancy or breastfeeding.
See also black seed oil benefits for blood sugar and cholesterol, rated by evidence.
See also do probiotics help weight loss? for an honest look at the gut supplement claims.
FAQs
What is berberine good for?
It’s mainly been studied for blood sugar and cholesterol, where trials show modest falls, mostly in people with type 2 diabetes or raised cholesterol. Weight loss in trials is small. It isn’t a treatment for any condition and doesn’t replace prescribed medicine.
Is berberine “nature’s Ozempic”?
No. Reviews of trials found average weight loss of about 1 to 2kg. In the main trials of weight loss injections, people lost around 15% to 21% of their body weight.
Can I take berberine with metformin?
Only if your GP or pharmacist agrees. Both lower blood sugar, so together they could add up, and the NHS says to tell your doctor about any supplements you take with metformin. Never stop or swap a prescribed medicine for a supplement.
What is the best time to take berberine?
No time of day has been shown to work better. Trials usually split the daily amount into two or three doses, often with meals. Follow the label and your pharmacist’s advice.
How long does berberine take to work?
In one small diabetes study, blood sugar started to fall within the first week. Weight effects were mainly seen after more than 8 weeks at over 1g a day, and were small. Most trials lasted 4 to 24 weeks, so long-term effects aren’t well known.
Is berberine safe in pregnancy or breastfeeding?
No. It’s linked to a harmful build-up of bilirubin in babies, which can cause brain damage, so it should be avoided in pregnancy and while breastfeeding. Never give it to babies or children.
Sources
- NCCIH. Berberine and weight loss: what you need to know.
- Memorial Sloan Kettering Cancer Center. Berberine.
- Zhao JV et al (2023). Overall and sex-specific effect of berberine on glycemic and insulin-related traits: a systematic review and meta-analysis of randomized controlled trials. Journal of Nutrition.
- Dong H et al (2012). Berberine in the treatment of type 2 diabetes mellitus: a systemic review and meta-analysis. Evidence-Based Complementary and Alternative Medicine.
- Blais JE et al (2023). Overall and sex-specific effect of berberine for the treatment of dyslipidemia in adults. Drugs; and Ye Y et al (2021). Efficacy and safety of berberine alone for several metabolic disorders. Frontiers in Pharmacology.
- Asbaghi O et al (2020). The effect of berberine supplementation on obesity parameters, inflammation and liver function enzymes. Clinical Nutrition ESPEN; and Elahi Vahed I et al (2026). The effect of berberine on obesity indices: a systematic review and meta-analysis. International Journal of Obesity.
- Yin J et al (2008). Efficacy of berberine in patients with type 2 diabetes mellitus. Metabolism.
- Ha S, Song X (2024). Berberine as adjuvant therapy for treating reduced fertility potential in women with polycystic ovary syndrome. Explore; Chen C et al (2015). A randomized clinical trial of berberine hydrochloride in patients with diarrhea-predominant irritable bowel syndrome. Phytotherapy Research; Chedid V et al (2014). Herbal therapy is equivalent to rifaximin for the treatment of small intestinal bacterial overgrowth. Global Advances in Health and Medicine.
- Moon JM et al (2021). Absorption kinetics of berberine and dihydroberberine and their impact on glycemia. Nutrients.
- Guo Y et al (2012). Repeated administration of berberine inhibits cytochromes P450 in humans; Wu X et al (2005). Effects of berberine on the blood concentration of cyclosporin A in renal transplanted recipients. European Journal of Clinical Pharmacology; Bonnichsen M et al (2022). Safety first, a harmful interaction between rivaroxaban and berberine. Internal Medicine Journal.
- Chan E (1993). Displacement of bilirubin from albumin by berberine. Biology of the Neonate.
- Wilding JPH et al (2021). Once-weekly semaglutide in adults with overweight or obesity; Jastreboff AM et al (2022). Tirzepatide once weekly for the treatment of obesity. New England Journal of Medicine.
- NHS. Metformin, Semaglutide and Tirzepatide.
- Food Standards Agency. Food supplements; Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register.
This guide is general information, not medical advice. Evopure doesn’t sell berberine. Evopure makes the Magnesium Glycinate Sleep Complex.
