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Updated on 3 October 2026 with 1,115 reviews from people who took British Supplements' berberine, written between July 2019 and September 2026, 4 studies of people taking berberine published between 2021 and 2026, and 9 sources on its plants and history, from Culpeper's Complete Herbal to a 2026 review of the Amur cork tree.
Someone on Mumsnet put it simply: they'd thought of trying berberine for a month, and they were wondering whether to bother. It's a fair thing to ask about something most people had never heard of. The place to start is what berberine actually is, where it comes from, and what's been measured.
We went through every review of British Supplements' Clean Genuine Berberine, 1,115 of them, written between July 2019 and September 2026, 1,071 of them by verified buyers. The research comes from four studies, in Frontiers in Pharmacology, the Journal of Nutrition, JAMA Network Open and Nature Communications. The history and the plants come from reviews and studies in Frontiers in Pharmacology, Molecules and Communications Biology, among others.
Berberine at a glance
| What it is | A plant compound, an alkaloid |
|---|---|
| Where it comes from | The roots, bark and stems of plants such as barberry, Indian barberry, the Amur cork tree, Chinese goldthread, goldenseal and Oregon grape |
| Colour and taste | Bright yellow and bitter |
| Forms sold | Mostly capsules and tablets of berberine HCl |
| In the UK | Sold as a food supplement |
Sources: Frontiers in Pharmacology (2018), Molecules (2026) and the Museum of Fine Arts, Boston.
What is berberine?
Berberine is a plant compound, an alkaloid, found in the roots, bark and stems of a long list of plants, according to a 2018 review in Frontiers in Pharmacology. The barberries, the 450 to 500 species of Berberis, are its main natural source.
Berberine is yellow. The inner bark of the Amur cork tree is bright yellow and bitter, according to a 2026 review in Molecules, and berberine is the yellow in the barberry dye once used on wool, silk and leather, according to the Museum of Fine Arts, Boston.
So when someone asks what berberine is and what it does, the short answer is a yellow, bitter compound that plants make, and what it does in people has been measured in trials for blood sugar, cholesterol and waist size. In the UK, berberine is sold as a food supplement, usually as capsules or tablets of berberine extract.
What is the history of berberine?
Berberine's history is the history of the yellow plants that carry it: barberry fruit is written on Assyrian clay tablets from around 650 BC, according to the 2018 Frontiers in Pharmacology review, and cork tree bark and goldthread root are both in the Shennong Bencao Jing, one of the oldest Chinese books on herbs, written between 25 and 220 AD. In order:
- Around 650 BC: barberry fruit is recorded on clay tablets in the library of the Assyrian king Ashurbanipal, according to the 2018 Frontiers in Pharmacology review.
- Ancient India: Indian barberry, the Himalayan shrub also called tree turmeric, has been used in traditional practice, Ayurveda included, for more than 2,500 years, according to a 2024 review in the Journal of Applied Biology and Biotechnology.
- 25 to 220 AD: Huang Lian, the root of Chinese goldthread, is first mentioned in the Shennong Bencao Jing (Shennong's Classic of Materia Medica), written in China's Eastern Han dynasty, according to a 2024 review in Frontiers in Pharmacology. Huang Bai, the bark of the cork trees, has its earliest record in the same book, according to the 2026 Molecules review.
- The 1650s: Nicholas Culpeper (1616 to 1654) gives barberry its own entry in The Complete Herbal.
- Before the 1800s: Native Americans used goldenseal's yellow root as a dye and in their own traditional practice, and settlers took it up in the 19th century, according to a US Forest Service bibliography of goldenseal.
- In the dye pot: barberry stems and roots were boiled to make a yellow dye for wool, leather and silk, and a yellow pigment for colouring prints, according to the Museum of Fine Arts, Boston.
- The early 1800s: seedless barberry growing starts in South Khorasan in Iran, where the dried berries, zereshk, are still grown around Birjand and Qaen, according to a 2014 review in Pharmacognosy Reviews.
- Late 1800s to early 1900s: the UK roots out its barberry, because the shrub is the alternate host of wheat stem rust, a crop disease; the last UK epidemic of it was in 1955, according to a 2018 study in Communications Biology led by the John Innes Centre.
- 1926: Yoshion Murakami and colleagues in Japan isolate berberine from the Japanese variety of the Amur cork tree, according to the 2026 Molecules review.
- 1941: the Amur cork tree's bark gets a record of its own, in the Korean Pharmacopoeia, after centuries of going by one name, Huangbai, with the Chinese cork tree's bark, according to the 2026 Molecules review.
- 1997: goldenseal is listed in Appendix II of CITES, the international trade convention, after demand and lost habitat cut its wild numbers, according to the US Forest Service bibliography.
- 1999: China protects the Amur cork tree as a National Second-Class Key Protected Plant, after its wild numbers fell, according to the 2026 Molecules review.
- 2004 to 2023: the 12 placebo-controlled trials pooled in a 2025 review in Frontiers in Pharmacology are published, in China, Mexico and India.
- 2005: China's pharmacopoeia lists Amur cork tree bark separately from Chinese cork tree bark for the first time, according to the 2026 Molecules review.
- 2013: wheat stem rust turns up on a single wheat plant in southern England, the first UK case in nearly 60 years, as barberry is being replanted for the endangered barberry carpet moth, according to the 2018 Communications Biology study.
Where does berberine come from?
Berberine comes from plants: the 2018 Frontiers in Pharmacology review lists it in the barberries, the cork trees, goldenseal, Chinese goldthread and Oregon grape, among others, with the bark and roots holding more of it than the rest of the berberine plant.
Berberine itself has no other name, but its plants do: in Chinese, Huang Bai is the cork tree bark and Huang Lian the goldthread root, and in India daruharidra is Indian barberry. Six of the plants, starting with the Amur cork tree:
What is the Amur cork tree?
The Amur cork tree, Phellodendron amurense, is a tree of north-east China, the Korean Peninsula, Japan and the Russian Far East, 10 to 20 metres tall, according to the 2026 Molecules review from Changchun University and Tonghua Normal University. Its outer bark is a thick, grey layer of cork with deep grooves, and under it sits a thin inner bark that's bright yellow, bitter and sticky.
The inner bark is the part used as Huang Bai, and berberine is one of the compounds in it. Huang Bai is recorded in the Shennong Bencao Jing, though for most of history the Amur cork tree's bark and the Chinese cork tree's bark went by that one name. Records of the Amur bark on its own start with the Korean Pharmacopoeia in 1941, and China's pharmacopoeia has listed it separately since 2005.
Berberine was isolated from the Japanese variety of the tree in 1926. Its wood is valued for fine furniture.
The review is plain about supply: wild Amur cork trees have declined since the 1960s through over-harvesting of the bark, felling and land clearance. China has protected the species since 1999, its Species Red List assesses it as Vulnerable, and a tree grown for its bark takes 10 to 15 years before it's harvested.
Why we use Amur cork tree bark
Our berberine comes from the bark of the Amur cork tree, one of the two barks the Chinese have called Huang Bai since the Shennong Bencao Jing, nearly two thousand years ago. The extract we buy is made from that bark: 35 kilos of it go into every kilo, refined to 97% berberine by the HCl method.
We specify all of it: the tree, the part, the ratio, the purity and then make the supplements ourselves in our own factory in Gilford: 422.5mg of berberine, plus 48.4mg of our Uptake Blend, which is equal parts black pepper, ginger and cumin extracts. Some brands fill that space with rice flour; ours carries the three spices instead.
What are barberries?
Barberries are the fruit of the barberry shrubs, Berberis, and common barberry, Berberis vulgaris, grows in British hedgerows, according to the 2018 Communications Biology study. Its stems and roots carry the berberine, and the bark of common barberry is about 5% berberine, according to the 2018 Frontiers in Pharmacology review.
Barberry is the shrub the UK rooted out in the late 1800s and early 1900s, because it hosts wheat stem rust. It has since been replanted, partly to give a home to the endangered barberry carpet moth, according to the same study.
What is Berberis aristata?
Berberis aristata is Indian barberry, also called tree turmeric, an evergreen shrub up to 4 metres tall that grows in the Himalayas, in India, Nepal and Bhutan, and in Sri Lanka, according to the 2024 Journal of Applied Biology and Biotechnology review. Its roots, bark and fruit are used in Ayurveda, where it goes by the name daruharidra, and its root is bitter.
The same review says the plant is in serious danger in the Indian Himalaya, because its roots are collected on a large scale for their berberine.
What is Coptis chinensis?
Coptis chinensis is Chinese goldthread, the plant whose root-like stem is Huang Lian, the berberine source first mentioned in China's Eastern Han dynasty, according to the 2024 Frontiers in Pharmacology review. The 2018 Frontiers in Pharmacology review puts it, with barberry, among the natural sources with the highest concentration of berberine.
What is goldenseal?
Goldenseal, Hydrastis canadensis, is a perennial of the buttercup family that grows in the rich hardwood forests of the north-eastern United States and Canada, according to the US Forest Service bibliography. Native Americans used its yellow root as a dye before settlers took it up in the 1800s.
Demand and lost habitat have cut its wild numbers so far that it has been listed in Appendix II of CITES, the international trade convention, since 1997.
What is Oregon grape?
Oregon grape, Mahonia aquifolium (also listed as Berberis aquifolium), is a shrub of the barberry family, and its roots contain berberine, according to the 2018 Frontiers in Pharmacology review, which lists the Mahonia shrubs among the plants that carry it.
What foods contain berberine?
Barberries are the food people mean, the berries of the barberry shrubs, but the plant keeps more of its berberine in its roots and bark than in its fruit, according to the 2018 Frontiers in Pharmacology review. So which fruit is high in berberine? Barberry, though its berries hold less of it than its roots and bark.
In Iran the dried berries are called zereshk, barberries in English, and are grown in South Khorasan, according to the 2014 review in Pharmacognosy Reviews, and they go into rice dishes such as zereshk polo. A supplement is different: the berberine is extracted and purified, and the amount in each capsule is printed on the label in milligrams.
How is berberine made?
Berberine is made by soaking dried bark or root in a solvent, such as ethanol, methanol or water with a little acid in it, which draws the berberine out, according to the 2018 Frontiers in Pharmacology review. The acid turns berberine into a salt that dissolves, and with hydrochloric acid you get berberine HCl.
The same review says berberine breaks down with heat and light, so how the bark is dried and how hot the extraction runs both change how much berberine you end up with. Shade-dried plant material gave much more than oven-dried in one study it describes.
Two numbers describe an extract. The ratio, such as 35 to 1, means 35 kilograms of dried bark went into each kilogram of extract; it says how much plant went in, not how much berberine comes out.
The percentage, such as 97%, is how much of the finished extract is berberine, so multiply it by the extract weight and you have the berberine itself: 500mg of extract at 97% is 485mg of berberine. Check whether a label gives that per capsule or per serving of two or three, because that changes the sum.
What is berberine HCl?
Berberine HCl is berberine hydrochloride, the salt berberine forms with hydrochloric acid, which is the acid used in an HCl extraction. It's what "berberine HCl" or "berberine hydrochloride" on a label means, and it's the same berberine: HCl names the salt, not a different compound. The 12 trials in the 2025 Frontiers in Pharmacology review all gave purified berberine, more than 95% pure, as tablets or capsules.
What does berberine do?
What berberine does for the body has been measured in people mostly for blood sugar, blood fats and waist size, according to a review of 12 placebo-controlled trials published in Frontiers in Pharmacology in July 2025, which pooled 889 people given 300mg to 1,500mg a day for 12 to 20 weeks.
So does berberine work? The trials give an answer question by question, and so do the people who took it: of 1,115 reviews of British Supplements' Clean Genuine Berberine, 143 mention cravings or appetite, 138 blood sugar and 124 weight.
When people search for berberine benefits, what berberine is good for or what it's used for, these are the questions they ask, with blood sugar, the one the trials measured most and the one people call the main benefit, first:
How does berberine work?
How berberine works is described in the lab studies the 2025 Frontiers in Pharmacology review draws on: it switches on an enzyme called AMPK, which cells use to manage their energy, so that tissues take up more glucose and handle fats differently, and that's the explanation the papers give for the blood sugar and blood fat changes measured in the trials.
How berberine works for weight loss comes back to the same enzyme, which is why the weight trials measured waists and blood fats.
Does berberine lower blood sugar?
In the trials, yes: fasting blood sugar came out 0.52 mmol/L lower on berberine than on placebo across 18 trials, and HbA1c 4.48 mmol/mol lower across seven, according to a review of placebo-controlled trials published in the Journal of Nutrition in October 2023.
The Journal of Nutrition review found the drops were bigger in people with diabetes, so berberine for diabetics is where the research is firmest, and the 2025 Frontiers in Pharmacology review found the same direction, 0.515 mmol/L lower across six trials.
Karen H. wrote that her HbA1c went from 48 to 44 over seven months of taking it, and she's one of 77 people who took British Supplements' Clean Genuine Berberine and wrote that it helped their blood sugar; six wrote that it made no difference or that their readings went up.
Does berberine help with weight loss?
Yes, say 51 people who took British Supplements' Clean Genuine Berberine, Heather among them: she wrote that she's lost a stone in a year, slow but consistent. Six wrote that it didn't help and five that their weight stayed put.
In the trials, the change that held up was in waist size: across four placebo-controlled trials in the 2025 Frontiers in Pharmacology review, waists came out 3.27 cm smaller on berberine than on the dummy capsule.
Does berberine reduce belly fat?
Waists, yes, in the trials; the deep fat round the organs, no: waists came out 3.27 cm smaller on berberine in the Frontiers in Pharmacology review, while a six-month trial of 337 adults with obesity, published in JAMA Network Open in January 2026, found no drop in visceral or liver fat on 1,000mg a day.
Joidy T., Sarah C. and Suzanne H. are three of the people who took British Supplements' Clean Genuine Berberine and wrote that they lost weight round the middle.
Does berberine suppress appetite?
Is berberine an appetite suppressant? Yes, say 46 people who took British Supplements' Clean Genuine Berberine and wrote that their appetite got smaller, Patrice W. among them, who wrote after nearly a month that it does suppress her appetite. 96 wrote that their cravings for sweet things eased, and four wrote that it didn't help or made them hungrier.
Can berberine lower cholesterol?
In the trials, yes: LDL cholesterol came out 0.495 mmol/L lower on berberine than on placebo across eight trials and 750 people, and total cholesterol 0.451 mmol/L lower across seven, according to the 2025 Frontiers in Pharmacology review. HDL, the kind you want higher, barely moved.
Phyllida E., who took it alongside a change of diet, is one of two people who took British Supplements' Clean Genuine Berberine and wrote that their cholesterol moved the right way. 44 reviews mention cholesterol; 12 of those people were still waiting on a result, and two wrote that nothing had changed or they weren't sure.
Is berberine good for PCOS?
Yes, say 15 people with PCOS who took British Supplements' Clean Genuine Berberine, Daniella B. among them, who wrote after more than six months that her PCOS symptoms have eased. Of the 19 reviews that mention PCOS, none says it didn't help.
Does berberine lower blood pressure?
Not in the trials: the three placebo-controlled trials in the 2025 Frontiers in Pharmacology review that measured blood pressure found no real difference between berberine and placebo. Seven people who took British Supplements' Clean Genuine Berberine wrote that theirs came down, Margaret N. and Mr g. among them.
How long does berberine take to work?
The trials ran 12 to 20 weeks in the 2025 Frontiers in Pharmacology review and six months in the JAMA Network Open trial, so that's the time the research gave it.
People who took British Supplements' Clean Genuine Berberine wrote about anything from weeks to a year: Suzanne H. and Vic S. both saw a change at three weeks, Suzanne in her cravings and Vic on her monitor, Karen H. had a lower HbA1c after seven months, and Heather lost a stone over a year.
What happens when you first start taking berberine, going by the reviews about weight, is that the cravings ease before the scales move; most who wrote about their weight noticed a change inside the first month or two.
What are the side effects of berberine?
Is berberine safe to take? Low blood sugar, nausea, constipation and mild stomach discomfort were the side effects reported most across the 12 trials in the 2025 Frontiers in Pharmacology review, and none of them was significantly more common on berberine than on placebo.
That's the downside to berberine as the trials recorded it: the review put the relative risk at 1.07 for any side effect and 1.44 for stomach and bowel ones, neither of them significant.
43 reviews of British Supplements' Clean Genuine Berberine mention side effects, and 11 of them say there weren't any. Kay A. wrote that it hasn't given her any side effects.
Is berberine bad for kidneys?
Not in the trials that checked: four of the 12 trials in the 2025 Frontiers in Pharmacology review tested kidney function with blood tests such as creatinine and found it normal, though none of the 12 was run in people with kidney disease.
The same four trials checked liver function and found it normal too, which is as far as the trials go on whether berberine can damage the liver or is hard on your liver and kidneys. Nobody who reviewed British Supplements' Clean Genuine Berberine wrote about their kidneys, and five wrote that they get up less often in the night to wee.
Is it safe to take berberine every day?
The trials gave berberine every day, for 12 to 20 weeks in the Frontiers in Pharmacology review and for six months in the JAMA Network Open trial, which recorded side effects at similar rates on berberine and placebo.
How long can you take berberine? Six months is the longest any of those trials ran, so the long-term record past that is people's own: Mrs h.l. wrote that she's taken British Supplements' Clean Genuine Berberine for about two years, and Marlene R. for a few years.
Can I take berberine if I'm not diabetic?
A trial of 15 healthy men from Capital Medical University in Beijing, published in Nature Communications in September 2021, found that a single 1g dose didn't change fasting blood sugar against placebo. Pilvi A., who wrote that she isn't diabetic, took British Supplements' Clean Genuine Berberine for her sweet tooth and says she no longer wants to eat the lot.
Low blood sugar is on the list of side effects the Frontiers in Pharmacology review's trials reported most, so if your blood sugar runs low, ask a pharmacist or GP first.
Who should avoid taking berberine?
Ask a pharmacist or your GP before taking berberine if you:
- take any medication
- are pregnant or breastfeeding
- have an operation booked
- have a liver or kidney condition
- have had an eating disorder
That list is also the answer to what not to mix berberine with: if it's prescribed, ask first.
How should I take berberine?
The trials gave berberine by mouth, two or three times a day, as tablets or capsules, according to the 2025 Frontiers in Pharmacology review, and most of the 46 people who took British Supplements' Clean Genuine Berberine and wrote how many they take settled on one or two a day.
How much berberine should I take a day?
The trials gave 300mg to 1,500mg a day, according to the 2025 Frontiers in Pharmacology review, and the 46 people who took British Supplements' Clean Genuine Berberine and wrote how many they take ranged from two or three capsules a week to four a day.
15 take one a day, 15 take two, 8 went from one to two, 6 take three or one with every meal. The most any of the 12 trials gave was 1,500mg a day, in three doses, which is as far as the research goes on how much berberine is too much.
Gordon N. takes two, one with breakfast and one with his evening meal.
Should berberine be taken at night or morning?
The trials split it into two or three doses through the day, according to the 2025 Frontiers in Pharmacology review, and of the 28 people who took British Supplements' Clean Genuine Berberine and wrote when they take it, 8 take it before a meal, 11 with or after food, and 1 on an empty stomach.
Vic S. takes one in the morning and one in the evening, and paul t. wrote that he sleeps better when he takes it before bed.
Where can I buy berberine in the UK?
You can buy berberine in the UK without a prescription, because it's sold as a food supplement: online, in health food shops and in pharmacies. British Supplements makes its own, Clean Genuine Berberine, in its factory in Gilford, Northern Ireland, and sells it with its reviews on its website.
Thinking of trying berberine?
Have a look at British Supplements' Clean Genuine Berberine: 422.5mg of berberine HCl from Amur cork tree bark in every capsule, made in our own UK factory with no fillers. 1,124 reviews as of 3 October 2026, rated 4.7 out of 5. Read them; they're real.
FAQ
Can you buy berberine over the counter in the UK?
You can: berberine is sold in the UK as a food supplement, so you don't need a prescription and you can buy it online, in health food shops and in pharmacies. If you take any medication, are pregnant or breastfeeding, or have a liver or kidney condition, ask a pharmacist or your GP before you start.
Is berberine vegan?
Berberine itself comes from plants, so yes, though whether a berberine supplement is vegan depends on the capsule and anything else that goes in it. British Supplements' Clean Genuine Berberine comes in a veg capsule and is listed as vegan on its product page.
What colour should berberine be?
Bright yellow: berberine is the compound that turns certain barks and roots yellow, and it was once used as a yellow dye for wool, silk and leather, according to the Museum of Fine Arts, Boston. Gary S. headed his review of British Supplements' Clean Genuine Berberine "Golden yellow and bitter taste as you would expect".
Is berberine a supplement?
Yes, in the UK berberine is sold as a food supplement, usually as capsules or tablets of berberine extract. It's a plant compound, an alkaloid, rather than a vitamin or a mineral, and it's extracted mostly from the bark and roots of plants such as the Amur cork tree and the barberries.
Is berberine the same as barberry?
No. Barberry is a plant, the Berberis shrubs, and berberine is a compound found in it, mostly in the roots and stem bark, according to the 2018 Frontiers in Pharmacology review. Berberine is also found in plants that aren't barberries at all, such as the Amur cork tree and goldenseal.
Is berberine just turmeric?
No. Turmeric is a different plant altogether, the root spice used in cooking, and berberine comes from plants such as barberry and the Amur cork tree. The two share a colour and, in one case, a name: Indian barberry, one of the berberine plants, is also called tree turmeric.
How do you know if berberine is working?
26 people who took British Supplements' Clean Genuine Berberine wrote that a blood test or a monitor reading came down, 10 of them with the figures; Vic S. wrote that her morning reading went from 7.8 to 5.5 mmol/L in three weeks. Four wrote that theirs didn't change or went up. Take any reading to a pharmacist or GP first.
Does berberine affect sleep?
Julie M. and Vuyo H. both wrote that they sleep better since taking British Supplements' Clean Genuine Berberine, Julie through the night, and nobody who took it wrote that their sleep got worse. If you sleep badly after starting it, tell a pharmacist or your GP.
Thinking of giving berberine a go?
Ours is 422.5mg per capsule, from Amur cork tree bark, made in our own factory with no fillers. 1,124 people have left a review, read a few before you decide. That's what they're there for.
Claire Cane
Claire is the researcher behind the berberine guides at British Supplements, where every capsule is made, packed and shipped from the company's own factory in Gilford.
Every article she writes is built from three things: the label, the published trials, and what the people who actually took it wrote in their reviews. No claims, just what happened to them and what the studies measured.
