Index of Herbs

Herbal formula

Turmeric and Black Pepper

Also known as Turmeric with black pepper, curcumin with piperine, curcumin–piperine, curcuminoids plus piperine, turmeric with BioPerine

Turmeric extract with piperine from black pepper to boost curcumin absorption; joint evidence is thin and liver and drug risks are real.

Main use: Knee osteoarthritis pain

Early or mixed evidence

2 ingredients

Updated October 10, 2026

Key points

  1. 01

    The famous 2000% comes from ten men

    A 1998 study gave ten young men curcumin with and without piperine. It measured blood levels, not symptoms, and later independent studies found no gain in free curcumin.

  2. 02

    Few trials test the pair itself

    Most turmeric trials did not use piperine. The main knee osteoarthritis trial of the combination had 40 patients and lasted six weeks.

  3. 03

    Pepper may add nothing for pain

    In a 2026 crossover trial, kitchen turmeric eased chronic pain equally with or without black pepper, although the study was small and had no placebo group.

  4. 04

    Liver injury is rare but real

    Regulators link liver injury mainly to high-dose, enhanced-absorption turmeric, often with pepper extract. Stop at once for yellow skin or eyes, dark urine, or unusual tiredness.

  5. 05

    Piperine can change drug levels

    Small studies found 20 mg of piperine raised levels of phenytoin, propranolol, and theophylline. Check with a pharmacist if you take any regular medicine.

Turmeric and black pepper is less a single branded product than a popular pairing. On supplement shelves it usually means capsules of turmeric rhizome extract, standardized to curcuminoids such as curcumin, with a small dose of piperine, the pungent alkaloid of black pepper, often as an extract standardized to about 95% piperine. In a 2026 survey of 125 turmeric supplements sold in Australia, Germany, India, the UK, and the USA, Rahim-Mahdy and Seifert found that black pepper extract was the most popular absorption enhancer, used in 23 products. Most clinical trials of the combination used tablets of 500 mg curcuminoids plus 5 mg piperine, taken one to three times a day. The pairing also turns up in the kitchen whenever turmeric and pepper go into the same dish, at far lower doses. This page covers the combination as a whole; the monographs on turmeric and black pepper cover each spice on its own.

Both spices have long histories in South Asian cooking and medicine. NCCIH, the US National Center for Complementary and Integrative Health, notes that turmeric has been used in Chinese, Indian (Ayurvedic), Islamic, and Thai traditional medicine for indigestion, colds, skin infections, arthritis, abdominal pain, and liver disease. The capsule pairing is much younger. In 1995 the supplement company Sabinsa filed a US patent, granted in 1996, on using piperine to increase the bioavailability of nutritional compounds, with Muhammed Majeed among the inventors. Two years later Shoba and colleagues (Planta Medica 1998), three of whose six authors, Majeed included, worked for the Bangalore supplier Sami Chemicals and Extracts, reported that piperine raised curcumin bioavailability by 2000%. That number became the standard selling point, and piperine became the most common absorption booster in curcumin research: Mimica and colleagues (Pharmaceuticals 2022) found it in 23% of 165 randomized trials.

The idea is simple. Curcumin is poorly absorbed and quickly converted in the gut wall and liver into glucuronide and sulfate conjugates. Piperine inhibits glucuronidation, and in laboratory studies it also blocks the drug pump P-glycoprotein and the drug-metabolizing enzyme CYP3A4, so adding it should let more curcumin reach the blood. Whether it does so in a way that matters for symptoms is disputed, and the same mechanism means piperine can raise blood levels of some prescription drugs. This page explains what the 1998 absorption study did and did not show, the few trials that tested curcumin with piperine for knee osteoarthritis and inflammation markers, how products are dosed, and the liver-injury warnings that regulators in Italy, Australia, and the European Union now attach to high-dose, enhanced-absorption turmeric. Nothing here is medical advice. Joint pain that is new, severe, or comes with swelling, redness, or fever needs a clinician’s assessment.

See also

Herbs for Joint Pain and Arthritis Herbs for Inflammation

02 The blend

What’s in it

Ingredients in label order. Results from trials of this formula belong to the combination, not to any single herb in it.

  1. Turmeric · Rhizome extract (curcuminoids)

    500 mg curcuminoids per tablet in most trials

    Curcuma longa

    Supplies curcumin and related curcuminoids. Retail labels range from about 250 to 3,000 mg per serving, often whole rhizome powder mixed with a smaller amount of extract standardized to 95% curcuminoids.

    Read the turmeric monograph →

  2. Black pepper · Fruit extract (piperine)

    5 mg piperine per tablet in most trials

    Piper nigrum

    Added to slow the breakdown of curcumin. Extracts are standardized to about 95% piperine and usually listed at 5 to 20 mg per serving; some products use ground pepper instead.

    Read the black pepper monograph →

03 Evidence

What the research shows

Early or mixed evidence

Our rating for knee osteoarthritis pain, based on trials of this combination.

The case for the pairing rests on Shoba and colleagues (Planta Medica 1998). Ten healthy men aged 20 to 26 took 2 g of curcumin alone and, after a two-week washout, the same dose with 20 mg of piperine. Curcumin alone was undetectable or very low in most blood samples, so its pharmacokinetics could not be calculated; with piperine, levels were higher from 15 minutes to one hour, and the authors reported a 2000% rise in bioavailability. That large percentage starts from a near-zero baseline and came from a team that included the supplier. Independent work with more precise mass spectrometry has not reproduced it. Kroon and colleagues (iScience 2025), funded by Amsterdam University Medical Centres, gave nine healthy men 2,400 mg of curcumin with or without 20 mg of piperine: free curcumin stayed below the detection limit either way, total exposure was similar, and they concluded piperine added no benefit. A 2026 review by an expert committee of the US Pharmacopeia (USP) reached the same view for the 5 to 20 mg typical of products. Blood levels, in any case, are not symptom relief.

Trials that gave curcumin with piperine for joint pain are few. The main one is a pilot, double-blind, placebo-controlled trial by Panahi and colleagues (Phytotherapy Research 2014), funded by Baqiyatallah University of Medical Sciences in Iran. Forty people with mild to moderate knee osteoarthritis took 1,500 mg of curcuminoids a day, with 15 mg of piperine according to the trial’s companion paper, or placebo for six weeks. The curcuminoid group improved more on the WOMAC osteoarthritis index, a pain scale, and the Lequesne index, in pain and physical function but not stiffness, with no notable side effects. In that companion paper, Rahimnia and colleagues (Drug Research 2015) found that inflammatory markers did not change differently from placebo. The only trial we found that tested what pepper adds was small. Durham and colleagues (Nutrients 2026), partly funded by the McCormick Science Institute, gave 30 adults with chronic pain encapsulated kitchen turmeric (300 mg, 1 g, or 3 g) for a week with and a week without 300 mg of ground black pepper. Pain fell over the study, but pepper made no significant difference, and there was no placebo group.

Most turmeric research did not use piperine at all. Mimica and colleagues found it in 23% of 165 randomized curcumin trials; others used phospholipid complexes, micelles, turmeric oils, or no enhancer. Reviews for knee osteoarthritis pool these products. Wai and colleagues (BMC Complementary Medicine and Therapies 2025) ran a network meta-analysis of 17 trials and found that every type of turmeric preparation reduced WOMAC pain compared with placebo; the bioavailability-enhanced group, which lumps piperine combinations together with micelles, nanoparticles, and other technologies, lowered pain by 2.47 points on average, but the certainty of evidence was rated low. A 2026 umbrella review by Shi and colleagues (Frontiers in Medicine) found consistent signals for pain and function across ten reviews, rated only three of them high quality, and noted that no head-to-head trials compare formulations. NCCIH calls the initial osteoarthritis evidence for turmeric or curcumin positive but says higher-quality studies are needed, as is more research on how bioavailability affects curcumin’s effects. These results support curcumin extracts in general, not the added pepper.

For inflammation markers, the combination has its own meta-analyses. Karimi and colleagues (Food Science and Nutrition 2025) pooled 18 randomized trials with 1,063 participants, 16 of them run in Iran. Curcumin with piperine lowered interleukin-6 (IL-6), with moderate certainty, and the liver enzyme AST, but did not significantly change C-reactive protein (CRP) or tumor necrosis factor-alpha, both rated low certainty. Individual trials show a similar pattern. In 100 people with type 2 diabetes, Panahi and colleagues (Drug Research 2018) found that 500 mg of curcuminoids with 5 mg of piperine daily for three months lowered fasting glucose (by 9 versus 3 mg/dL) and HbA1c (by 0.9 versus 0.2 percentage points) more than placebo, but did not change high-sensitivity CRP. Majeed, the piperine patent’s co-inventor, co-authored that diabetes trial and a 2025 meta-analysis of inflammation outcomes (Hosseini and colleagues, Current Medicinal Chemistry). Changes in blood markers are not the same as less joint damage or fewer heart attacks.

No regulator has approved turmeric with black pepper as a medicine. In the United States these products are dietary supplements, which the Food and Drug Administration (FDA) does not approve before sale. In the European Union, the European Medicines Agency (EMA) has a monograph only for turmeric root on its own, as a traditional herbal medicine for adults with digestive complaints such as fullness, slow digestion, and flatulence, and its summary says combinations are not covered. The monograph’s highest daily dose, 4 g of turmeric, corresponds to at most about 209 mg of curcuminoids, a fraction of the 500 to 1,500 mg used in the combination trials. In a review adopted in November 2025, EMA’s herbal committee noted that liver-injury cases with enough product detail often involved pepper extract or intakes above the monograph’s doses, and said a drug-interaction warning for bioavailability enhancers should be explored at its next review. Italy has required liver and gallstone warnings on turmeric supplements since 2019, Australia’s Therapeutic Goods Administration (TGA) issued a liver-injury advisory in 2023, and USP recommended a liver caution for its turmeric monographs in 2026.

Much remains unknown. We found no adequately sized, independent, placebo-controlled trial comparing curcumin with and without piperine on a clinical outcome such as knee pain, so it is unproven that pepper adds anything beyond curcumin itself. A 2026 systematic review of 20 curcumin–piperine trials by Pan and colleagues (Frontiers in Nutrition) found sample sizes of 8 to 117 people and durations of 1 to 12 weeks, too small and short to judge rare harms or long-term effects. Results from turmeric trials without piperine cannot simply be borrowed for this pairing, because absorption, dose, and interaction risk differ between products; equally, results from the 500 mg-plus-5 mg trial tablets do not automatically apply to retail capsules with other amounts. Overall, we rate the evidence for knee osteoarthritis pain as mixed: one small positive pilot trial of the combination, supportive but low-certainty reviews of curcumin products in general, and a direct comparison that found no added benefit from the pepper.

04 In practice

How it is taken

Turmeric-and-black-pepper supplements come as capsules, tablets, softgels, gummies, and powders, sometimes with ginger or other herbs added. Labels vary widely. In a sample of about 40 products on the market that we checked in the Dietary Supplement Label Database of the NIH Office of Dietary Supplements in October 2026, turmeric was listed at roughly 250 to 3,000 mg per serving, often as whole rhizome powder plus a smaller amount of extract standardized to 95% curcuminoids. Black pepper extract was usually listed at 5 to 20 mg per serving; some products used 10 to 200 mg of ground pepper instead, and some gummies listed only 100 micrograms. Rahim-Mahdy and Seifert found that 34% of 125 turmeric supplements did not state their curcuminoid content at all. Whole rhizome powder is only a few percent curcuminoids (2.34% on average in batches tested for the European Pharmacopoeia, according to EMA), so 1,000 mg of powder is not 1,000 mg of curcumin. Turmeric with a pinch of pepper in cooking is food: TGA and the Italian Ministry of Health found no reason for concern about turmeric in normal dietary amounts.

The trials used fixed amounts. Most gave tablets of 500 mg curcuminoids with 5 mg piperine, one to three times a day; the knee osteoarthritis pilot used 1,500 mg of curcuminoids and 15 mg of piperine daily for six weeks, and Pan and colleagues found piperine doses of 5 to 15 mg and curcumin doses of 500 to 1,500 mg a day across 20 trials. NCCIH considers conventionally formulated turmeric or curcumin, not modified to enhance absorption, likely safe in recommended amounts for up to two or three months; it does not extend that reassurance to enhanced-absorption products, and piperine combinations are sold as exactly that. If knee pain has not improved after the six weeks of the main trial, the research offers no evidence that a higher dose or a longer course will help. Stop at once and contact a clinician for any sign of liver trouble, and see a clinician rather than self-treating for a hot, swollen joint or pain after an injury.

When choosing a product, look for three numbers on the label: the amount of curcuminoids (not just “turmeric”), the amount of piperine or black pepper extract, and the number of capsules per serving. A label that states them lets you compare it with trial doses and tell a pharmacist exactly what you take. Avoid stacking several turmeric or curcumin products, or adding other enhanced-absorption formulas, since the liver cases involved high doses and enhanced absorption. The pepper itself is optional: independent pharmacokinetic studies found no gain in free curcumin, and the one direct pain trial found no added benefit. Norway’s Scientific Committee for Food Safety (VKM) judged 1.5 mg of piperine a day from supplements unlikely to cause harm and noted that doses above 10 mg might lead to clinically significant drug interactions, so people on regular medicines may prefer a product without piperine, after checking with a pharmacist. Supplements are not approved by the FDA before sale, and their contents are the manufacturer’s responsibility.

05 Caution

Before you use Turmeric and Black Pepper

Side effects in the combination trials were generally mild: the knee osteoarthritis pilot reported no considerable adverse effects, and Pan and colleagues found none of significance across 20 short trials. NCCIH lists nausea, vomiting, acid reflux, stomach upset, diarrhea, and constipation for oral turmeric. The most serious risk is liver injury. The US Drug-Induced Liver Injury Network (DILIN) described 10 cases of turmeric-associated liver injury enrolled since 2011, usually appearing one to four months after starting; five people were hospitalized, one died, and 3 of the 7 products tested also contained piperine (Halegoua-DeMarzio and colleagues, American Journal of Medicine 2023). In Tuscany, Lombardi and colleagues (British Journal of Clinical Pharmacology 2021) described seven cases of acute hepatitis up to September 2019, all linked to high-dose, high-bioavailability turmeric products. TGA had received 18 Australian reports by June 2023, including one death. The USP review notes that most injuries resolve once the product is stopped. A case report also describes iron-deficiency anemia that resolved after a man stopped high-dose turmeric capsules (Smith and Ashar, Cureus 2019).

Avoid these supplements if you have, or have had, liver disease or a supplement-related liver injury; TGA advises people with existing or previous liver problems to avoid curcumin products. EMA does not recommend medicinal turmeric with bile-duct obstruction, cholangitis, liver disease, gallstones, or other biliary disease, because it may stimulate bile secretion, and Italy’s label warning says the same for altered liver or bile function and gallstones. EMA does not recommend turmeric medicines in pregnancy or breastfeeding, NCCIH says turmeric supplements may be unsafe in pregnancy, and the USP review reports that Italy added a warning against use in pregnancy and breastfeeding in 2022; we found no human safety data on concentrated piperine in pregnancy. EMA does not recommend medicinal turmeric for anyone under 18, and Norway’s piperine assessment covered only people aged 10 and over, so these products are not for children or teenagers. People with anemia, a bleeding disorder, or upcoming surgery should talk to a clinician first.

Both ingredients interact with medicines. Piperine inhibits P-glycoprotein and CYP3A4 in laboratory studies (Bhardwaj and colleagues, Journal of Pharmacology and Experimental Therapeutics 2002). In small human studies, 20 mg a day for a week raised blood levels of propranolol and theophylline in six volunteers per drug (Bano and colleagues, European Journal of Clinical Pharmacology 1991), and a single 20 mg dose raised phenytoin levels in 20 people with epilepsy (Pattanaik and colleagues, Phytotherapy Research 2006). In breast cancer patients, curcumin with piperine lowered exposure to endoxifen, the active form of tamoxifen, by 12.4% (Hussaarts and colleagues, Cancers 2019). Not every drug is affected: a curcuminoid–piperine product did not change midazolam, flurbiprofen, or paracetamol in eight volunteers (Volak and colleagues 2013). Memorial Sloan Kettering Cancer Center (MSKCC) warns that turmeric may raise bleeding risk with warfarin and other blood thinners and lists tacrolimus, and the combination lowered blood glucose in the diabetes trial. Anyone taking an epilepsy drug, blood thinner, diabetes medicine, transplant drug, tamoxifen, or other cancer treatment should ask a pharmacist first.

Stop the product and contact a clinician promptly for yellowing of the skin or eyes, dark urine, itching, nausea or vomiting, unusual tiredness or weakness, loss of appetite, or stomach or abdominal pain; TGA and NCCIH list these as possible signs of liver injury, and early recognition reduces the risk of severe harm. Do not restart the product to see whether it was the cause. Severe abdominal pain, especially with fever or yellowing, needs urgent care, particularly in anyone with known gallstones. A joint that is suddenly hot, red, and swollen, especially with fever, needs same-day medical assessment rather than a supplement, as does new joint pain after an injury. Unusual bruising or bleeding in someone on a blood thinner, or shakiness and sweating suggesting low blood sugar in someone on diabetes medicines, should also be reported. Tell every clinician who treats you, including surgeons and anesthetists, about any turmeric or piperine product you take, and tell your prescriber when you start or stop one, since stopping can change drug levels again.

06 Questions

Frequently Asked Questions

Less clearly than labels suggest. The famous figure comes from a 1998 study in which 20 mg of piperine raised curcumin bioavailability about 2000% in ten young men, measured as blood levels, not symptoms. Later independent studies with more precise methods found that piperine did not raise free curcumin, and a 2026 trial found that kitchen turmeric eased chronic pain equally with or without black pepper. For each spice on its own, see the turmeric and black pepper monographs.

No. Turmeric powder is only a few percent curcuminoids, about 2.3% on average in batches tested for the European Pharmacopoeia, while supplement extracts are often standardized to 95% and trial tablets held 500 mg of curcuminoids each. A pinch of pepper also supplies far less piperine than a capsule extract. Australia’s TGA and Italy’s Ministry of Health found no reason for concern about turmeric in normal dietary amounts; their liver warnings are about concentrated supplements.

Possibly, but the evidence for the pair itself is thin. One pilot trial in 40 people with knee osteoarthritis found that 1,500 mg of curcuminoids with piperine daily for six weeks eased pain and improved function more than placebo. Reviews of curcumin products in general are encouraging but rate the certainty of evidence low, and most of those products contained no piperine. Whether the black pepper adds anything is unproven, and knee pain that keeps you from walking or sleeping deserves a clinician’s assessment.

It changes some blood markers but not others. A 2025 meta-analysis of 18 trials found that curcumin with piperine lowered interleukin-6 but did not significantly lower C-reactive protein, the most widely used inflammation test. In the knee osteoarthritis trial, inflammatory markers did not change differently from placebo, and the authors concluded that the pain relief could not be explained by a body-wide anti-inflammatory effect. Laboratory anti-inflammatory activity does not make it a substitute for treating inflammatory disease.

Rarely, yes. The US Drug-Induced Liver Injury Network described 10 turmeric-related cases, usually one to four months after starting, with one death; 3 of the 7 products tested contained piperine. Italy, Australia, and the European Medicines Agency link the risk mainly to high-dose, enhanced-absorption products, which often contain pepper extract. Most people recover after stopping. Stop at once and see a clinician for yellow skin or eyes, dark urine, itching, nausea, unusual tiredness, loss of appetite, or abdominal pain.

Piperine raised blood levels of phenytoin, propranolol, and theophylline in small studies, and curcumin with piperine lowered levels of the active form of tamoxifen in breast cancer patients. Turmeric may add to the bleeding risk of warfarin and other blood thinners, and the combination lowered blood glucose in people with type 2 diabetes. Other drugs, such as midazolam and paracetamol, were unaffected in one short study. If you take any regular medicine, ask a pharmacist before starting, and tell your prescriber if you start or stop.

People with current or past liver disease or supplement-related liver injury; people with gallstones, bile-duct obstruction, or other biliary disease; pregnant or breastfeeding women; and children and teenagers under 18. People taking blood thinners, epilepsy drugs, diabetes medicines, transplant drugs, or cancer treatment should check with a pharmacist first, and anyone facing surgery should tell the surgical team. Turmeric and pepper in ordinary cooking are a different, much smaller exposure.

Usually 5 to 20 mg per serving, from extracts standardized to about 95% piperine, although some products use ground pepper and some gummies contain only a fraction of a milligram. Trials of the combination used 5 to 15 mg a day, and the 1998 absorption study used 20 mg. Norway’s food safety committee judged 1.5 mg a day from supplements unlikely to cause harm and noted that doses above 10 mg might cause clinically significant drug interactions. More piperine has not been shown to mean more benefit.

07 References

Sources

These references support the claims on this page. They are not an endorsement of any product. Each ingredient’s monograph carries its own full source list.

  1. Influence of piperine on the pharmacokinetics of curcumin in animals and human volunteers

    Planta Medica (PubMed 9619120), 1998

    Shoba et al.: randomized crossover in ten healthy men aged 20–26; 2 g curcumin alone mostly undetectable; 20 mg piperine raised bioavailability 2000%; compounds supplied by Sami Chemicals and Extracts, employer of three authors.

  2. A pharmacokinetic study and critical reappraisal of curcumin formulations enhancing bioavailability

    iScience (PubMed 40487425), 2025

    Kroon et al.: independent crossover in nine healthy men; adding 20 mg piperine to 2,400 mg curcumin did not raise free or total curcumin; funded by Amsterdam UMC.

  3. Methods Used for Enhancing the Bioavailability of Oral Curcumin in Randomized Controlled Trials: A Meta-Research Study

    Pharmaceuticals (PubMed 36015087), 2022

    Mimica et al.: of 165 curcumin RCTs, 64% used an absorption-enhancing method and 23% added piperine; very few compared products.

  4. Curcuminoid treatment for knee osteoarthritis: a randomized double-blind placebo-controlled trial

    Phytotherapy Research (PubMed 24853120), 2014

    Panahi et al.: pilot RCT in 40 patients; 1,500 mg/day curcuminoids for six weeks improved WOMAC, pain scale, and Lequesne scores but not stiffness; university funded.

  5. Impact of Supplementation with Curcuminoids on Systemic Inflammation in Patients with Knee Osteoarthritis: Findings from a Randomized Double-Blind Placebo-Controlled Trial

    Drug Research (PubMed 25050518), 2015

    Rahimnia et al.: same 40-patient trial; confirms 15 mg/day piperine was added; changes in IL-4, IL-6, hs-CRP, TNF-α, TGF-β, and ESR did not differ from placebo.

  6. Bioenhancer Assessment of Black Pepper with Turmeric on Self-Reported Pain Ratings in Adults: A Randomized, Cross-Over, Clinical Trial

    Nutrients (PubMed 41599836), 2026

    Durham et al.: 30 adults with chronic pain; culinary turmeric with or without 300 mg black pepper for a week each; pain fell but pepper made no difference; no placebo; partly funded by the McCormick Science Institute.

  7. Effect of turmeric products on knee osteoarthritis: a systematic review and network meta-analysis

    BMC Complementary Medicine and Therapies (PubMed 40731001), 2025

    Wai et al.: 17 RCTs; all turmeric preparations reduced WOMAC pain versus placebo; piperine products pooled with other enhanced forms; low certainty of evidence.

  8. Effects of Curcuminoids Plus Piperine Co-Supplementation on Liver Enzymes and Inflammation in Adults: A GRADE-Assessed Systematic Review and Meta-Analysis

    Food Science and Nutrition (PubMed 40661794), 2025

    Karimi et al.: 18 RCTs, 1,063 participants, 16 trials from Iran; IL-6 and AST reduced; CRP and TNF-α not significantly changed.

  9. Effects of Curcuminoids Plus Piperine on Glycemic, Hepatic and Inflammatory Biomarkers in Patients with Type 2 Diabetes Mellitus: A Randomized Double-Blind Placebo-Controlled Trial

    Drug Research (PubMed 29458218), 2018

    Panahi et al.: 100 patients; 500 mg curcuminoids plus 5 mg piperine daily for three months lowered glucose and HbA1c versus placebo but not hs-CRP.

  10. Turmeric: Usefulness and Safety

    National Center for Complementary and Integrative Health (NIH), 2025

    Products often contain piperine; initial osteoarthritis evidence positive but more research needed on bioavailability; conventional forms likely safe for 2–3 months; liver damage with bioavailable forms; pregnancy caution.

  11. Curcumae longae rhizoma: EU herbal monograph and 2025 assessment addendum

    European Medicines Agency (EMA), Committee on Herbal Medicinal Products, 2026

    Traditional use for mild digestive complaints in adults; not recommended with biliary disease, in pregnancy, or under 18; combinations not covered; 2025 addendum links liver risk to high-dose, high-bioavailability products often containing pepper extract.

  12. Medicines containing turmeric or curcumin - risk of liver injury

    Therapeutic Goods Administration (Australia), 2023

    18 Australian reports to June 2023 including one death; risk may be higher for enhanced-absorption or higher-dose products; not linked to dietary amounts; warning symptoms listed.

  13. Integratori alimentari contenenti estratti e preparati di Curcuma longa

    Ministero della Salute (Italian Ministry of Health), 2019

    After cholestatic hepatitis cases, mostly with high-curcumin products often combined with absorption enhancers, Italy required label warnings for liver, bile, and gallstone disorders and medicine users.

  14. Liver Injury Associated with Turmeric—A Growing Problem: Ten Cases from the Drug-Induced Liver Injury Network [DILIN]

    The American Journal of Medicine (PubMed 36252717), 2023

    Halegoua-DeMarzio et al.: 10 US cases since 2011; latency 1–4 months; five hospitalized, one death; 3 of 7 products tested contained piperine; strong HLA-B*35:01 link.

  15. Rarely reported cases of hepatotoxicity associated with turmeric- and curcuminoid-containing dietary supplements: a comprehensive review by USP

    Pharmaceutical Biology (PubMed 42364655), 2026

    USP expert committee: liver injury rare, typically after 1–4 months and resolving on stopping; typical 5–20 mg piperine doses do not meaningfully raise curcuminoids; recommends a liver caution; summarizes Italian 2022 label changes.

  16. Effect of piperine on bioavailability and pharmacokinetics of propranolol and theophylline in healthy volunteers

    European Journal of Clinical Pharmacology (PubMed 1815977), 1991

    Bano et al.: six volunteers per drug; 20 mg piperine daily for 7 days raised peak levels and exposure of propranolol and theophylline.