Berberine: every public report we counted

Where these came from

• Diabetes.co.uk forum 13 reports
• Diabetes Daily forum 13 reports
• Mumsnet 8 reports
• City-Data forum 4 reports
• QVC Community 2 reports

Blood sugar and type 2 diabetes

27 reports: 14 helped, 9 no effect or worse, 4 mixed or too early.

• Helped Within about a week, after-meal readings were near 131 instead of 180-210 and morning readings fell from the 140s to the 120s. Diabetes.co.uk forum, 2023-12-16 (Only one week in; started cinnamon at the same time; planned to check with doctor because of heart medicines.)
• Worse After two weeks developed severe pain across the upper abdomen that stopped within 48 hours of quitting; a later report mentions stomach ache again. Side effects: severe upper abdominal pain. Diabetes.co.uk forum, 2023-12-16 (Poster attributes the pain to berberine because nothing else changed; no glucose result given.)
• Mixed A first brand made little difference and an HbA1c check was only slightly better; a later refrigerated brand seemed to bring readings into the 4s. Diabetes.co.uk forum, 2024-11-23 (Already in non-diabetic range; poster calls the first try inconclusive and possibly natural progress.)
• Helped After four months with bitter melon, halved diabetes medicine and was still having low blood sugar episodes. Side effects: low blood sugar episodes (hypos) while on gliclazide. Diabetes.co.uk forum, 2024-12-30 (Two supplements started together; the hypos happened alongside a sulfonylurea, the combination doctors warn about.)
• No effect Took it with every meal but could not tell how much it helped and it did not fix morning highs; metformin later worked far better. Diabetes.co.uk forum, 2024-08-12 (Poster judges berberine at most a small help; no numbers for the berberine period.)
• Worse Stopped after one week at 1,500 mg a day because of intestinal pain; fasting glucose was unchanged; later attempts caused the same pain. Side effects: intestinal pain. Diabetes.co.uk forum, 2023-10-18 (Only one week of glucose data; an earlier attempt was interrupted by diverticulitis.)
• No effect Switched from metformin because of side effects; berberine had no side effects but, like metformin, barely moved fasting glucose. Diabetes.co.uk forum, 2024-08-13 (Poster says HbA1c is hard to attribute because they use several measures at once.)
• Helped Takes it twice a day and thinks it helps; most recent HbA1c was 39 mmol/mol, in the normal range. Diabetes.co.uk forum, 2024-08-22 (No before value or duration given.)
• Worse Fine for a day, then severe stomach pain and diarrhoea worse than on metformin, so stopped; now controls glucose with diet. Side effects: severe diarrhoea, stomach pain. Diabetes.co.uk forum, 2024-05-02 (Short trial; no glucose result.)
• No effect Took two capsules a day for a while; any lowering of glucose was marginal and not worth it next to free metformin. Diabetes.co.uk forum, 2024-05-17 (Poster says it may have helped slightly.)
• Mixed Berberine alone did not work; after adding black seed oil, walking and fewer carbs, glucose became responsive. Quit twice early on from gut discomfort. Side effects: intestinal discomfort at the start. Diabetes.co.uk forum, 2023-09-26 (Several changes at once; no after value for HbA1c.)
• Worse After a couple of months it caused persistent diarrhoea, worse than standard metformin; will not try again. Side effects: chronic diarrhoea. Diabetes.co.uk forum, 2023-10-19 (No glucose result given.)
• Helped Used it for about a year and thinks it helped blood sugar; stopped over worries about long-term effects on gut bacteria. Diabetes Daily forum, 2025-07-18 (No numbers.)
• No effect Took three different brands for months at a time and saw no improvement in blood glucose or anything else. Diabetes Daily forum, 2025-07-22 (Brands not tested for content.)
• Helped About a week in, cut metformin to 500 mg and readings stayed in the 80s and low 90s; later said it beats metformin for them. Diabetes Daily forum, 2020-07-25 (Short time frame; another member notes the poster had lost weight and was mildly diabetic.)
• Helped Could not take metformin; has taken 1,500 mg a day for years with no side effects and sees higher readings when a dose is missed. Diabetes Daily forum, 2019-11-26 (Posted across several threads 2016-2020; no lab values.)
• Mixed Took it from October 2019; it worked somewhat but readings never fell below 195, and it stopped working after a few months. Diabetes Daily forum, 2020-07-29 (No baseline given.)
• Helped Average fasting glucose fell from 144 to 106 within about two weeks; a year later, on metformin too, still felt it helped. Diabetes Daily forum, 2020-07-30 (Cinnamon started at the same time; poster says they cannot prove it.)
• Helped With 500 mg three times daily and a diet change, HbA1c fell from 8.1% to 6.3% in three months, then 5.6%; lost 25 lb. Diabetes Daily forum, 2015-09-11 (Diet changed at the same time; another member questioned whether this new account was promoting a brand.)
• No effect Took a generic brand for three months and saw no change in blood glucose. Diabetes Daily forum, 2016-01-04 (Brand not tested; later planned to try another brand.)
• Helped Has gone on and off it and says it clearly cuts morning glucose release and improves after-meal readings after a few weeks. Diabetes Daily forum, 2016-01-16 (No numbers; long-time advocate in that forum.)
• Too early A few days in, a fasting reading was 86 and after-meal numbers looked lower than before. Diabetes Daily forum, 2016-01-19 (Only days of use; vinegar taken too.)
• Helped Replaced metformin with berberine plus a ketogenic diet; reports good glucose numbers and visible weight loss. Diabetes Daily forum, 2018-04-07 (Diet change is a large confounder; no lab values.)
• Helped A multi-ingredient product containing berberine lowered readings by about 30-40 points on days taken; weight did not change. Diabetes Daily forum, 2019-11-26 (Product is a blend, so berberine's share is unknown.)
• Helped Takes a low dose with other herbs; says it boosts metformin so less is needed, and manages diabetes with herbs, diet and exercise. City-Data forum, 2019-07-07 (Several herbs at once; no numbers.)
• Helped Replaced metformin with 1,200 mg a day plus diet; HbA1c 5.6%, the same as on metformin; also stopped a blood-pressure pill. City-Data forum, 2021-11-01 (Single HbA1c value; stopping a blood-pressure medicine was the poster's own choice.)
• Helped With diet, exercise, stress and sleep changes plus berberine, HbA1c fell from 14 to 8 in a year; metformin and glipizide had not suited. City-Data forum, 2022-01-28 (Many changes at once; berberine's share unknown.)

Cholesterol and blood fats

3 reports: 1 helped, 2 no effect or worse, 0 mixed or too early.

• Helped Cannot tolerate metformin, so takes 500 mg twice daily instead; says cholesterol is better and has had no side effects. Diabetes.co.uk forum, 2023-10-19 (No numbers; glucose effect not described.)
• Worse Over a 3.5-month trial, triglycerides rose 15%, LDL rose 2 points and HDL fell 10%. QVC Community, 2024-09 (Diet changed at the same time; small LDL change may be noise; thread posts dated September 2024.)
• No effect Took berberine with red yeast rice and other supplements for a long stretch on a cardiologist's advice with no improvement. QVC Community, 2024-09 (Familial high cholesterol; now on a prescription injection that works.)

Body weight

8 reports: 3 helped, 1 no effect or worse, 4 mixed or too early.

• No effect Lost 4 lb in week one, then nothing; about eighteen months later said it had not worked much and she gave up. Side effects: hunger and rumbling stomach in first days. Mumsnet, 2025-01-18 (Early loss may be normal fluctuation, as she noted.)
• Helped Taking 500 mg a day and lost 16 lb over about two months. Mumsnet, 2023-06-08 (Poster stresses a strict low-carb diet as well.)
• Too early About two weeks in, losing weight on a health drive and feels berberine is curbing appetite. Side effects: mild constipation (poster blames diet). Mumsnet, 2023-06-22 (No amounts; had read it can take three months.)
• Too early Ten days in, lost 4 lb and found appetite lower, while also fasting and eating fewer carbs. Side effects: more frequent bowel movements. Mumsnet, 2023-06-23 (Poster says diet may explain the appetite change.)
• Helped Took it with myo-inositol for over a year with diet and exercise; lost a stone and a half with no side effects. Mumsnet, 2023-06-22 (Several changes together; poster credits the combination.)
• Helped Lost 7.6 lb in three weeks and felt appetite suppressed, while also taking a fibre supplement and fasting 18 hours a day. Side effects: gas and bloating in week 3. Mumsnet, 2024-04-20 (Only three weeks; two other weight-loss measures at once.)
• Too early Took it for one day, was very gassy, and did not take it again. Side effects: gas. Mumsnet, 2022-10-25 (One day only.)
• Too early Nearly a month in with no ill effects once taken with food; had not weighed yet. Side effects: gas when taken before meals. Mumsnet, 2022-10-30 (No outcome measured.)

Other uses and general experience

2 reports: 0 helped, 1 no effect or worse, 1 mixed or too early.

• Mixed In 2020 said cholesterol labs improved on twice-daily berberine; in 2025 said a year of it made little or no difference. Diabetes Daily forum, 2025-07-18 (Two posts five years apart; the 2025 post does not say which measure.)
• Worse At 1,100 mg a day, normal blood pressure dropped too far; two weeks in had spinning vertigo that took two weeks to clear after stopping. Side effects: blood pressure dropped too low, vertigo lasting two weeks. City-Data forum, 2024-11-11 (Poster still believes it works; no glucose or weight result.)