Berberine

Pharmacology & Research

Berberine is a quaternary isoquinoline (protoberberine) alkaloid — the bright-yellow pigment of barberry, goldthread and goldenseal roots. For a single plant molecule it has an unusually large clinical literature, and almost all of it is on the isolated compound: multiple randomised trials and meta-analyses support modest metabolic benefits (blood sugar, cholesterol, fatty liver), while its classic antimicrobial activity is largely in vitro. One fact frames everything else — oral bioavailability is under ~1%, so most of what berberine does happens in the gut and liver rather than through high blood levels ^{9Reference 9Murakami T et al. · 2023ReviewApproaching strategy to increase the oral bioavailability of berberine, a quaternary isoquinoline alkaloid — reviewView study →}.

0. Evidence by application

Support is an experimental score I’m building — a composite weighted by study type (human > animal > in vitro > review) and study volume, tempered for isolate-vs-plant match and bioavailability. It’s a beta: a fast way to rank strength of evidence at a glance, not a validated metric, and I’ll keep honing it. Each application links down to its write-up.

Application	Support	Rests on
Glycaemic control	████████░░ 82%	Human RCTs + meta-analysis, incl. head-to-head vs metformin; trials small/short 1,2,3Reference 1Zhang Y et al. · 2008RCTTreatment of type 2 diabetes and dyslipidemia with the natural plant alkaloid berberine — randomised controlled trialView study →Reference 2Yin J et al. · 2008RCTEfficacy of berberine in patients with type 2 diabetes mellitus — randomised trial (head-to-head vs metformin)View study →Reference 3Lan J et al. · 2015Meta-analysisMeta-analysis of the effect and safety of berberine in the treatment of type 2 diabetes mellitus, hyperlipemia and hypertension — meta-analysis (27 trials, n=2,569)View study →
Cholesterol & triglycerides	████████░░ 78%	18-RCT placebo-controlled meta-analysis; effects modest 4Reference 4Blais JE et al. · 2023Meta-analysisOverall and sex-specific effect of berberine for the treatment of dyslipidemia in adults — systematic review and meta-analysis of randomised placebo-controlled trials (18 RCTs, n=1,788)View study →
Fatty liver (NAFLD)	██████░░░░ 64%	Multicentre RCT + 6-RCT meta-analysis 5,6Reference 5Yan HM et al. · 2015RCTEfficacy of berberine in patients with non-alcoholic fatty liver disease — randomised controlled trial (n=184)View study →Reference 6Wei X et al. · 2016Meta-analysisThe therapeutic effect of berberine in the treatment of nonalcoholic fatty liver disease — meta-analysis (6 RCTs, n=501)View study →
Polycystic ovary syndrome (PCOS)	█████░░░░░ 48%	Meta-analysis of 12 RCTs; mixed, no hard reproductive outcomes 7Reference 7Xie L et al. · 2019Meta-analysisThe effect of berberine on reproduction and metabolism in women with polycystic ovary syndrome — systematic review and meta-analysis of randomised controlled trials (12 RCTs)View study →
Gut antimicrobial & antidiarrhoeal	████░░░░░░ 40%	Traditional + in-vitro (incl. FtsZ mechanism); limited by bioavailability 8Reference 8Boberek JM et al. · 2010In vitroGenetic evidence for inhibition of bacterial division protein FtsZ by berberine — in vitroView study →

1. Glycaemic control

Berberine’s strongest evidence. A 2008 double-blind RCT (n=116, 1 g/day, 3 months) lowered HbA1c and fasting and post-prandial glucose versus placebo ^{1Reference 1Zhang Y et al. · 2008RCTTreatment of type 2 diabetes and dyslipidemia with the natural plant alkaloid berberine — randomised controlled trialView study →}. A separate 2008 trial ran berberine 0.5 g three times daily head-to-head with metformin in newly diagnosed type 2 diabetes and found a similar glucose-lowering effect, with HbA1c falling roughly 2 percentage points ^{2Reference 2Yin J et al. · 2008RCTEfficacy of berberine in patients with type 2 diabetes mellitus — randomised trial (head-to-head vs metformin)View study →}. A 2015 meta-analysis of 27 trials (2,569 patients) concluded berberine performed comparably to standard oral hypoglycaemics with no serious adverse events ^{3Reference 3Lan J et al. · 2015Meta-analysisMeta-analysis of the effect and safety of berberine in the treatment of type 2 diabetes mellitus, hyperlipemia and hypertension — meta-analysis (27 trials, n=2,569)View study →}. All used the isolated molecule.

Gap: the trials are overwhelmingly small, short and single-region with high risk of bias — “comparable to metformin” is a short-term signal, not established equivalence ^{3Reference 3Lan J et al. · 2015Meta-analysisMeta-analysis of the effect and safety of berberine in the treatment of type 2 diabetes mellitus, hyperlipemia and hypertension — meta-analysis (27 trials, n=2,569)View study →}.

2. Cholesterol & triglycerides

A 2023 systematic review and meta-analysis of 18 placebo-controlled RCTs (n=1,788, 0.9–1.5 g/day) found berberine reduced LDL cholesterol by about 0.46 mmol/L, with similar falls in total cholesterol and triglycerides, a small sex-specific HDL rise, and no serious adverse events ^{4Reference 4Blais JE et al. · 2023Meta-analysisOverall and sex-specific effect of berberine for the treatment of dyslipidemia in adults — systematic review and meta-analysis of randomised placebo-controlled trials (18 RCTs, n=1,788)View study →}.

Gap: the effect sizes are modest (LDL ≈ 18 mg/dL) and heterogeneity across trials is high — berberine reads as an adjunct, not a statin substitute ^{4Reference 4Blais JE et al. · 2023Meta-analysisOverall and sex-specific effect of berberine for the treatment of dyslipidemia in adults — systematic review and meta-analysis of randomised placebo-controlled trials (18 RCTs, n=1,788)View study →}.

3. Fatty liver (NAFLD)

A multicentre RCT (n=184, 0.5 g three times daily plus lifestyle, 16 weeks) cut hepatic fat significantly more than lifestyle alone and beat pioglitazone on weight and lipids ^{5Reference 5Yan HM et al. · 2015RCTEfficacy of berberine in patients with non-alcoholic fatty liver disease — randomised controlled trial (n=184)View study →}. A meta-analysis of 6 RCTs (n=501) likewise found improvements in liver enzymes, lipids and glucose versus controls ^{6Reference 6Wei X et al. · 2016Meta-analysisThe therapeutic effect of berberine in the treatment of nonalcoholic fatty liver disease — meta-analysis (6 RCTs, n=501)View study →}.

Gap: the trials are few and of limited quality, and imaging endpoints (liver-fat fraction) carry more weight than the enzyme changes often reported ^{6Reference 6Wei X et al. · 2016Meta-analysisThe therapeutic effect of berberine in the treatment of nonalcoholic fatty liver disease — meta-analysis (6 RCTs, n=501)View study →}.

4. Polycystic ovary syndrome (PCOS)

A 2019 meta-analysis of 12 RCTs found berberine may improve insulin resistance, androgen levels and the LH/FSH ratio in women with PCOS, sometimes comparably to metformin ^{7Reference 7Xie L et al. · 2019Meta-analysisThe effect of berberine on reproduction and metabolism in women with polycystic ovary syndrome — systematic review and meta-analysis of randomised controlled trials (12 RCTs)View study →}.

Gap: the evidence is smaller and more heterogeneous than for diabetes, and there is no solid evidence berberine improves live birth or other hard reproductive outcomes ^{7Reference 7Xie L et al. · 2019Meta-analysisThe effect of berberine on reproduction and metabolism in women with polycystic ovary syndrome — systematic review and meta-analysis of randomised controlled trials (12 RCTs)View study →}.

5. Gut antimicrobial & antidiarrhoeal

Berberine is a traditional remedy for infectious diarrhoea and has broad in-vitro activity against bacteria (including drug-resistant strains), fungi and protozoa; genetic work shows one key antibacterial mechanism is inhibition of the bacterial cell-division protein FtsZ, rather than DNA binding ^{8Reference 8Boberek JM et al. · 2010In vitroGenetic evidence for inhibition of bacterial division protein FtsZ by berberine — in vitroView study →}. Because oral berberine concentrates in the gut lumen rather than the bloodstream, any real effect is plausibly enteric.

Gap: robust human trials for infection are lacking, and systemic antimicrobial use is precluded by <1% bioavailability ^{8,9Reference 8Boberek JM et al. · 2010In vitroGenetic evidence for inhibition of bacterial division protein FtsZ by berberine — in vitroView study →Reference 9Murakami T et al. · 2023ReviewApproaching strategy to increase the oral bioavailability of berberine, a quaternary isoquinoline alkaloid — reviewView study →}.

Mechanisms

Target / pathway	Effect	Relevant to
AMPK activation	↑ glucose uptake, ↓ hepatic gluconeogenesis & lipogenesis	glycaemic control, cholesterol, fatty liver
Hepatic LDL-receptor upregulation	↑ LDL clearance from blood	cholesterol & triglycerides
Gut-microbiota modulation	altered bile-acid & short-chain-fatty-acid signalling	glycaemic control, fatty liver
Bacterial FtsZ inhibition	blocks cell division (bacteriostatic)	gut antimicrobial

Pharmacokinetics

Berberine’s defining pharmacological fact is poor oral bioavailability — under ~1% (reported as low as ~0.4% in animals) — the result of low solubility, self-aggregation, extensive first-pass metabolism and active efflux back into the gut by P-glycoprotein ^{9Reference 9Murakami T et al. · 2023ReviewApproaching strategy to increase the oral bioavailability of berberine, a quaternary isoquinoline alkaloid — reviewView study →}. It is metabolised to several active or semi-active metabolites (berberrubine, thalifendine, demethyleneberberine, jatrorrhizine), and the gut microbiota convert some berberine to dihydroberberine, a reduced form that is absorbed far better ^{9,10Reference 9Murakami T et al. · 2023ReviewApproaching strategy to increase the oral bioavailability of berberine, a quaternary isoquinoline alkaloid — reviewView study →Reference 10Dehau T et al. · 2023ReviewBerberine–microbiota interplay: modulation of the gut microbiota and metabolic transformation into bioactive metabolites — reviewView study →}. The practical upshot: much of berberine’s benefit is exerted locally in the gut and liver, plasma levels stay low, and formulation (or dihydroberberine) rather than raw dose is the main lever on exposure ^{9,10Reference 9Murakami T et al. · 2023ReviewApproaching strategy to increase the oral bioavailability of berberine, a quaternary isoquinoline alkaloid — reviewView study →Reference 10Dehau T et al. · 2023ReviewBerberine–microbiota interplay: modulation of the gut microbiota and metabolic transformation into bioactive metabolites — reviewView study →}.

Clinical trials

Berberine has been tested in many investigator-led randomised trials — chiefly in type 2 diabetes, dyslipidaemia, NAFLD and PCOS — but as an off-patent natural product it attracts little registered industry-sponsored trial activity.

Completed	Planned	Terminated	Preclinical
Many (metabolic)	Several	—	Extensive

Last checked: July 2026.

Monoamine oxidase (MAO) inhibition

Berberine is also a weak monoamine oxidase inhibitor — a reported IC50 around 126 µM for MAO-A, with similarly high (weak) MAO-B values ^{18Reference 18Kong et al. · 2001Monoamine oxidase inhibitors from rhizoma of Coptis chinensisView study →} — i.e. concentrations far higher than those at which it acts on its metabolic targets. MAO inhibition is therefore a minor footnote in berberine’s pharmacology rather than a primary mechanism, and it is comfortably outclassed by the flavonoid and β-carboline inhibitors covered in the natural MAO inhibitors guide.

Isolate vs. Plant Studies

Almost all of berberine’s clinical evidence comes from the isolated molecule — the diabetes, lipid, NAFLD and PCOS trials used purified berberine (typically the hydrochloride salt), not whole-plant preparations ^{1,2,4Reference 1Zhang Y et al. · 2008RCTTreatment of type 2 diabetes and dyslipidemia with the natural plant alkaloid berberine — randomised controlled trialView study →Reference 2Yin J et al. · 2008RCTEfficacy of berberine in patients with type 2 diabetes mellitus — randomised trial (head-to-head vs metformin)View study →Reference 4Blais JE et al. · 2023Meta-analysisOverall and sex-specific effect of berberine for the treatment of dyslipidemia in adults — systematic review and meta-analysis of randomised placebo-controlled trials (18 RCTs, n=1,788)View study →}. That makes berberine unusual among plant constituents: its human data genuinely describe the compound, not a plant extract standing in for it. The whole-plant relationship runs the other way — traditional use of barberry, goldthread or goldenseal root is often attributed to berberine, but those roots carry many alkaloids (jatrorrhizine, palmatine, and in goldenseal hydrastine), so a whole-root effect can’t be assumed to be berberine alone. Read the trials as evidence for the molecule and the traditional record as evidence for the plants.

Prevalence in Nature

Berberine is made by plants across at least five families — Ranunculaceae (Coptis, Hydrastis/goldenseal, Xanthorhiza), Berberidaceae (Berberis, Mahonia, Nandina), Rutaceae (Phellodendron, Zanthoxylum), Papaveraceae (Argemone, Eschscholzia/California poppy, Sanguinaria) and Menispermaceae ^{11Reference 11Neag MA et al. · 2018ReviewBerberine: botanical occurrence, traditional uses, extraction methods, and relevance in cardiovascular, metabolic, hepatic, and renal disorders — reviewView study →}. It concentrates in roots, rhizomes and bark rather than leaves: the richest sources are the rhizomes of Coptis species and the inner bark of Phellodendron amurense (Amur cork tree), reported from the low single digits up to roughly 8% of dry weight, with Berberis stem/bark and goldenseal rhizome lower ^{11Reference 11Neag MA et al. · 2018ReviewBerberine: botanical occurrence, traditional uses, extraction methods, and relevance in cardiovascular, metabolic, hepatic, and renal disorders — reviewView study →}.

Biosynthetically it is a benzylisoquinoline alkaloid built from two molecules of the amino acid tyrosine. The pathway runs through (S)-reticuline — the branch-point of this whole alkaloid family — to (S)-scoulerine in the committed step, catalysed by the berberine bridge enzyme, a flavin-dependent oxidase that forms the characteristic “berberine bridge” carbon, and then on through canadine to berberine ^{12Reference 12Bird DA · 2001Berberine bridge enzyme, converting (S)-reticuline to (S)-scoulerine in benzylisoquinoline alkaloid biosynthesis — plant biochemistryView study →}. Berberine is essentially a plant product, with no established natural animal, fungal or bacterial source; recent work has both shown the pathway can evolve convergently (Phellodendron forms the bridge with a different, cytochrome-P450 enzyme) and reconstructed the full route in engineered yeast ^{13Reference 13Xu Z et al. · 2024Convergent evolution of berberine biosynthesis — plant genomicsView study →}.

Discovery & Synthesis

Berberine was first isolated in the early nineteenth century and takes its name from the genus Berberis (barberry), from which it was among the first alkaloids obtained; its vivid yellow colour made it a dye long before its pharmacology was studied ^{11Reference 11Neag MA et al. · 2018ReviewBerberine: botanical occurrence, traditional uses, extraction methods, and relevance in cardiovascular, metabolic, hepatic, and renal disorders — reviewView study →}. The first total chemical synthesis was reported by Kametani and co-workers in 1969 (as the iodide salt) ^{17Reference 17American Chemical SocietyMolecule of the Week: BerberineView study →}. Commercially, though, berberine is almost never synthesised: the plants that make it — chiefly Coptis chinensis rhizome (huánglián), Phellodendron bark and Berberis species — are so rich in it that solvent extraction is far cheaper than total or semi-synthesis, so essentially all supplement-grade berberine (usually berberine hydrochloride) is plant-extracted ^{11Reference 11Neag MA et al. · 2018ReviewBerberine: botanical occurrence, traditional uses, extraction methods, and relevance in cardiovascular, metabolic, hepatic, and renal disorders — reviewView study →}.

Patents: not yet researched (future patent-loop pass).

Toxicity & Safety

Berberine is generally well tolerated at the doses used in trials (~0.9–1.5 g/day), with adverse effects that are mostly gastrointestinal — constipation, diarrhoea, cramping or nausea — more frequent than placebo but rarely serious ^{3,4Reference 3Lan J et al. · 2015Meta-analysisMeta-analysis of the effect and safety of berberine in the treatment of type 2 diabetes mellitus, hyperlipemia and hypertension — meta-analysis (27 trials, n=2,569)View study →Reference 4Blais JE et al. · 2023Meta-analysisOverall and sex-specific effect of berberine for the treatment of dyslipidemia in adults — systematic review and meta-analysis of randomised placebo-controlled trials (18 RCTs, n=1,788)View study →}. The interactions matter more than the side effects: a controlled human study showed repeated oral berberine inhibits the drug-metabolising enzymes CYP2D6, CYP2C9 and CYP3A4, so it can raise blood levels of many medications ^{14Reference 14Guo Y et al. · 2011RCTRepeated administration of berberine inhibits cytochromes P450 in humans — randomised human pharmacokinetic studyView study →}, and combined CYP3A4-plus-P-glycoprotein inhibition raised cyclosporine concentrations in transplant recipients — a clinically important effect for narrow-margin drugs ^{15Reference 15Wu X et al. · 2005Clinical trialEffects of berberine on the blood concentration of cyclosporin A in renal transplant recipients — controlled clinical studyView study →}. No formal maximum tolerated dose is established; trials generally cap around 1.5 g/day, above which GI intolerance rises ^{4,14Reference 4Blais JE et al. · 2023Meta-analysisOverall and sex-specific effect of berberine for the treatment of dyslipidemia in adults — systematic review and meta-analysis of randomised placebo-controlled trials (18 RCTs, n=1,788)View study →Reference 14Guo Y et al. · 2011RCTRepeated administration of berberine inhibits cytochromes P450 in humans — randomised human pharmacokinetic studyView study →}.

Pregnancy & lactation

Avoid. Berberine displaces bilirubin from serum albumin — in vitro far more potently than the reference drug phenylbutazone — and it crosses the placenta and enters breast milk; in a newborn, whose liver cannot yet clear bilirubin, this raises the risk of kernicterus (bilirubin brain injury) ^{16Reference 16Chan E · 1993In vitroDisplacement of bilirubin from albumin by berberine — in vitro and rat studyView study →}. It is therefore contraindicated in pregnancy, breastfeeding and neonates ^{16,17Reference 16Chan E · 1993In vitroDisplacement of bilirubin from albumin by berberine — in vitro and rat studyView study →Reference 17American Chemical SocietyMolecule of the Week: BerberineView study →}.

Dosage

Clinical trials have most often used 900–1,500 mg per day of berberine (usually the hydrochloride), split into two or three doses with meals — divided dosing is standard because absorption is low and saturable ^{1,3Reference 1Zhang Y et al. · 2008RCTTreatment of type 2 diabetes and dyslipidemia with the natural plant alkaloid berberine — randomised controlled trialView study →Reference 3Lan J et al. · 2015Meta-analysisMeta-analysis of the effect and safety of berberine in the treatment of type 2 diabetes mellitus, hyperlipemia and hypertension — meta-analysis (27 trials, n=2,569)View study →}.

Application	Form	Dose (studied)	Source
Type 2 diabetes	Berberine HCl	500 mg ×2–3/day	1,2Reference 1Zhang Y et al. · 2008RCTTreatment of type 2 diabetes and dyslipidemia with the natural plant alkaloid berberine — randomised controlled trialView study →Reference 2Yin J et al. · 2008RCTEfficacy of berberine in patients with type 2 diabetes mellitus — randomised trial (head-to-head vs metformin)View study →
Dyslipidaemia	Berberine HCl	900–1,500 mg/day	4Reference 4Blais JE et al. · 2023Meta-analysisOverall and sex-specific effect of berberine for the treatment of dyslipidemia in adults — systematic review and meta-analysis of randomised placebo-controlled trials (18 RCTs, n=1,788)View study →
NAFLD	Berberine HCl	500 mg ×3/day	5Reference 5Yan HM et al. · 2015RCTEfficacy of berberine in patients with non-alcoholic fatty liver disease — randomised controlled trial (n=184)View study →

Bioavailability-enhanced forms (e.g. dihydroberberine, or berberine paired with absorption enhancers) reach higher plasma levels at lower doses but are less studied for hard outcomes ^{9Reference 9Murakami T et al. · 2023ReviewApproaching strategy to increase the oral bioavailability of berberine, a quaternary isoquinoline alkaloid — reviewView study →}. These are doses studied in research and are not a personal recommendation — appropriateness depends on the individual, their medications (see interactions above) and professional guidance.

References

1. Zhang Y, Li X, Zou D, Liu W, Yang J, Zhu N, et al. (2008). Treatment of type 2 diabetes and dyslipidemia with the natural plant alkaloid berberine — randomised controlled trial. Journal of Clinical Endocrinology & Metabolism, 93(7), 2559–2565. https://pubmed.ncbi.nlm.nih.gov/18397984/
2. Yin J, Xing H, Ye J. (2008). Efficacy of berberine in patients with type 2 diabetes mellitus — randomised trial (head-to-head vs metformin). Metabolism, 57(5), 712–717. https://pubmed.ncbi.nlm.nih.gov/18442638/
3. Lan J, Zhao Y, Dong F, Yan Z, Zheng W, Fan J, Sun G. (2015). Meta-analysis of the effect and safety of berberine in the treatment of type 2 diabetes mellitus, hyperlipemia and hypertension — meta-analysis (27 trials, n=2,569). Journal of Ethnopharmacology, 161, 69–81. https://pubmed.ncbi.nlm.nih.gov/25498346/
4. Blais JE, Huang X, Zhao JV. (2023). Overall and sex-specific effect of berberine for the treatment of dyslipidemia in adults — systematic review and meta-analysis of randomised placebo-controlled trials (18 RCTs, n=1,788). Drugs, 83(5), 403–427. https://pubmed.ncbi.nlm.nih.gov/36941490/
5. Yan HM, Xia MF, Wang Y, Chang XX, Yao XZ, Rao SX, et al. (2015). Efficacy of berberine in patients with non-alcoholic fatty liver disease — randomised controlled trial (n=184). PLoS ONE, 10(8), e0134172. https://pubmed.ncbi.nlm.nih.gov/26252777/
6. Wei X, Wang C, Hao S, Song H, Yang L. (2016). The therapeutic effect of berberine in the treatment of nonalcoholic fatty liver disease — meta-analysis (6 RCTs, n=501). Evidence-Based Complementary and Alternative Medicine, 2016, 3593951. https://doi.org/10.1155/2016/3593951
7. Xie L, Zhang D, Ma H, He H, Xia Q, Shen W, et al. (2019). The effect of berberine on reproduction and metabolism in women with polycystic ovary syndrome — systematic review and meta-analysis of randomised controlled trials (12 RCTs). Evidence-Based Complementary and Alternative Medicine, 2019, 7918631. https://pubmed.ncbi.nlm.nih.gov/31915452/
8. Boberek JM, Stach J, Good L. (2010). Genetic evidence for inhibition of bacterial division protein FtsZ by berberine — in vitro. PLoS ONE, 5(10), e13745. https://pubmed.ncbi.nlm.nih.gov/21060782/
9. Murakami T, Bodor E, Bodor N. (2023). Approaching strategy to increase the oral bioavailability of berberine, a quaternary isoquinoline alkaloid — review. Expert Opinion on Drug Metabolism & Toxicology, 19(3). https://pubmed.ncbi.nlm.nih.gov/37057922/
10. Dehau T, Cherlet M, Croubels S, Van De Vliet M, Goossens E, Van Immerseel F. (2023). Berberine–microbiota interplay: modulation of the gut microbiota and metabolic transformation into bioactive metabolites — review. Frontiers in Pharmacology, 14, 1281090. https://doi.org/10.3389/fphar.2023.1281090
11. Neag MA, Mocan A, Echeverría J, Pop RM, Bocsan CI, Crişan G, Buzoianu AD. (2018). Berberine: botanical occurrence, traditional uses, extraction methods, and relevance in cardiovascular, metabolic, hepatic, and renal disorders — review. Frontiers in Pharmacology, 9, 557. https://pubmed.ncbi.nlm.nih.gov/30186157/
12. Bird DA, Facchini PJ. (2001). Berberine bridge enzyme, converting (S)-reticuline to (S)-scoulerine in benzylisoquinoline alkaloid biosynthesis — plant biochemistry. Planta, 213(6), 888–897. https://pubmed.ncbi.nlm.nih.gov/11722125/
13. Xu Z, et al. (2024). Convergent evolution of berberine biosynthesis — plant genomics. Science Advances, 10, eads3596. https://pubmed.ncbi.nlm.nih.gov/39612339/
14. Guo Y, Chen Y, Tan ZR, Klaassen CD, Zhou HH. (2011). Repeated administration of berberine inhibits cytochromes P450 in humans — randomised human pharmacokinetic study. European Journal of Clinical Pharmacology, 68(2), 213–217. https://pubmed.ncbi.nlm.nih.gov/21870106/
15. Wu X, Li Q, Xin H, Yu A, Zhong M. (2005). Effects of berberine on the blood concentration of cyclosporin A in renal transplant recipients — controlled clinical study. European Journal of Clinical Pharmacology, 61(8), 567–572. https://pubmed.ncbi.nlm.nih.gov/16133554/
16. Chan E. (1993). Displacement of bilirubin from albumin by berberine — in vitro and rat study. Biology of the Neonate, 63(4), 201–208. https://pubmed.ncbi.nlm.nih.gov/8513024/
17. American Chemical Society. Molecule of the Week: Berberine. https://www.acs.org/molecule-of-the-week/archive/b/berberine.html
18. Kong, L. D., Cheng, C. H. K., & Tan, R. X. (2001). Monoamine oxidase inhibitors from rhizoma of Coptis chinensis. Planta Medica, 67(1), 74-76. https://pubmed.ncbi.nlm.nih.gov/11270727/