Bear Bile
Xióng Dǎn 熊胆 (active compound: UDCA)
Its real active compound is now a safe synthetic medicine.
Evidence tier
Banned / Harmful
Research weight
Not supported
Citations
19 verified / 19
Classification
TCM Herb
⊘
What the evidence says. Linked to serious harm and/or banned in sport and many jurisdictions. Listed for awareness and safety only — NOT a recommendation.
⚠
Health warning. International trade in bear bile is banned under CITES and bile-bear farming is widely condemned as cruel. The active compound (UDCA) is available as a safe, cheap synthetic medicine — there is no medical need for bear-derived bile.
What is Bear Bile?
Bear Bile (Xióng Dǎn 熊胆 (active compound: UDCA)) is a traditional Chinese medicine herb marketed for (compound) genuine: udca treats certain gallstones & liver disease. NutriDex grades the human evidence as Banned / Harmful. Bear bile is unusual: its principal compound, ursodeoxycholic acid (UDCA), genuinely treats some gallstones and liver conditions — and has been manufactured synthetically since the 1950s. That makes bile extracted from live, caged 'bile bears' both medically unnecessary and ethically indefensible. International trade is prohibited under CITES, and farming is illegal in several countries. Use the synthetic medicine instead.
Marketed Claims (unproven)
✕(Compound) genuine: UDCA treats certain gallstones & liver disease
✕(Claimed in TCM) 'clears heat', liver/eye complaints
Dosing & Compounds
Use & Legality
Do NOT use bear-derived bile. The legitimate medicine is synthetic ursodeoxycholic acid (UDCA), prescribed and dosed by a physician.
Active Compounds
Safety & Cautions
⚠ Farmed bear bile may be contaminated and is produced through extreme animal cruelty. Trade is banned (CITES). For genuine indications, only pharmaceutical synthetic UDCA should be used, under medical supervision. Educational only — always check with your doctor or pharmacist before combining Bear Bile with any medicine.
Evidence & Risk Findings ★ 19 studies
meta-analysis
UDCA gallstone prophylaxis meta-analysis 2023
✓ PubMed
Meta-analysis of 12 RCTs (n=2,767 bariatric surgery patients) found prophylactic ursodeoxycholic acid markedly reduced postoperative gallstone formation (risk ratio ~0.13, P<0.0001), confirming the synthetic compound's genuine efficacy.
meta-analysis
UDCA cardiometabolic meta-analysis 2025
✓ Full text
Systematic review and meta-analysis of 12 RCTs reported that ursodeoxycholic acid significantly improved several cardiometabolic risk factors (inflammation, blood pressure, and obesity-related markers) versus control.
meta-analysis
UDCA NAFLD meta-analysis 2024
✓ PubMed
Systematic review and meta-analysis of 7 RCTs found that ursodeoxycholic acid significantly reduced liver enzymes in nonalcoholic fatty liver disease patients (ALT p<=0.0001, AST p=0.0009, GGT p<=0.0001 versus control), indicating a hepatoprotective effect of the synthetic compound.
umbrella review
UDCA primary biliary cholangitis umbrella meta-analysis 2026
✓ Full text
Umbrella meta-analysis of 23 meta-analyses (45 unique RCTs, n=3,276) in primary biliary cholangitis found that synthetic UDCA monotherapy lowered alkaline phosphatase (mean difference -32.1 U/L, 95% CI -58.4 to -5.8) and that UDCA-fibrate combination therapy was superior (-85.4 U/L), supporting UDCA as the genuine first-line treatment.
Meta-analysis
BMC Cardiovasc Disord 2025
✓ Source
Systematic review and meta-analysis of 12 randomized trials (from 7,912 screened, searched through Aug 2024) evaluating UDCA effects on inflammation, blood pressure, and obesity-related cardiometabolic risk factors.
Systematic review
Gazda et al. 2022
✓ PubMed
Systematic review/meta-analysis of 16 UDCA treatment-response endpoints and 96 external validations in PBC found the continuous GLOBE and UK-PBC Risk Scores to be the most accurate validated predictors of long-term outcome; ALP plus total bilirubin normalization proposed as the optimal trial endpoint guiding second-line therapy allocation.
Meta-analysis
Ovadia et al. 2021
✓ PubMed
IPD meta-analysis (6,974 women, 34 studies) in intrahepatic cholestasis of pregnancy: UDCA had no significant effect on stillbirth overall (aOR 1.04), but when restricted to RCTs it was associated with a reduced composite of stillbirth plus preterm birth (aOR 0.60, 95% CI 0.39-0.91; p=0.016).
Guideline
EASL Clinical Practice Guidelines 2017
✓ PubMed
European Association for the Study of the Liver recommends oral UDCA 13-15 mg/kg/day as first-line therapy for all patients with PBC and elevated cholestatic enzymes, to slow disease progression and prevent end-stage liver disease.
Agency / regulator
CITES
✓ Source
International commercial trade in bear bile is prohibited.
RCT
PITCHES (Chappell et al.) 2019
✓ PubMed
Double-blind multicenter RCT (n=605) in intrahepatic cholestasis of pregnancy: UDCA did NOT reduce the composite adverse perinatal outcome (perinatal death, preterm birth, neonatal unit admission) vs placebo (23% vs 27%; adjusted RR 0.85, 95% CI 0.62-1.15). Routine use for this indication should be reconsidered.
review
Bears in TCM welfare-economics review 2025
✓ Source
Critical review argues that the use of bears in traditional Chinese medicine inflicts severe welfare harms on the ~17,000 farmed bears and is not kinder than modern medicine, given that synthetic UDCA fully substitutes for bile.
cohort study
UDCA and COVID-19 cohort 2023
✓ PubMed
Propensity-matched cohort of 450 chronic liver disease patients found UDCA users had a lower SARS-CoV-2 infection rate (85.3% vs 94.2%, p=0.002; OR~0.32) and faster recovery, supporting the FXR/ACE2 mechanism.
cohort study
UDCA and severe COVID-19 OpenSAFELY 2024
✓ Full text
Large OpenSAFELY population cohort study evaluated whether ursodeoxycholic acid was associated with reduced severe COVID-19 outcomes (hospitalisation/death), providing real-world data on the repurposed synthetic drug.
Observational
Brevini 2022 (Nature)
✓ Full text
UDCA downregulates ACE2 expression via FXR inhibition, reducing SARS-CoV-2 cell entry in human and animal models, suggesting a host-directed prophylactic mechanism against COVID-19.
Review
Substitute review 2017
✓ PubMed
Synthetic UDCA and herbal alternatives make farmed bile medically unnecessary.
Cohort
Harms et al. (Global PBC Study Group) 2019
✓ PubMed
International cohort of 3,902 PBC patients: UDCA therapy was associated with markedly improved 10-year transplant-free survival (79.7% vs 60.7% untreated) and a 54% lower risk of liver transplant or death (HR 0.46, 95% CI 0.40-0.52; p<0.001). Benefit held across all disease stages and even in incomplete biochemical responders (HR 0.56). Supports UDCA as universal standard of care.
field study
Bear farming motivations Vietnam 2022
✓ Source
Mixed-methods study of bear bile farming in Vietnam found that despite a 2005 ban and available synthetic/herbal alternatives, an illegal captive-bile industry persists, driven by entrenched demand and farmer economics.
Mechanism
Brevini et al. 2022
✓ PubMed
Nature study: FXR directly regulates ACE2 transcription; UDCA (an FXR inhibitor) downregulated ACE2 and reduced SARS-CoV-2 susceptibility in human organoids, animals, and ex situ perfused human lungs/livers, and lowered nasal ACE2 in humans. Retrospective registry and liver-transplant cohort data linked UDCA use to better COVID-19 outcomes.
Mechanism
UDCA pharmacology
✓ Full text
Ursodeoxycholic acid genuinely treats certain gallstones/liver disease — and is made synthetically.