Intake & Dosage

What lies behind it

The form matters most. Turmeric powder consists of about 2–6% curcuminoids [4]; in an analysis of 28 spice products, pure turmeric powder averaged 3.14% curcumin, and curry powders contained clearly less, with large variation [5]. Extracts and capsules deliver many times more. For curcumin as a food colour (E 100), EFSA assumed an ADI of 3 mg per kg body weight per day in 2010. Intake from the normal diet was below 7% of that [1]. For 70 kg this is arithmetically 210 mg curcumin, or roughly 6.7 g of powder at 3.14% content. That is our own calculation, and the ADI applies to the additive, not to the spice.

What the sources show

Extracts: In a phase I study, 25 patients with precancerous conditions took curcumin for three months. There was no treatment-related toxicity up to 8,000 mg/day; higher amounts were unacceptable because of their volume [2]. In 15 patients with advanced colorectal cancer, 0.45–3.6 g/day was taken for up to four months without dose-limiting toxicity [6]. In healthy volunteers given single doses of 500–12,000 mg, 7 of 24 reported only minimal complaints that were not dose-related [7].

Turmeric water: The water solubility of curcumin is about 0.6 µg/ml; heating raised it to 7.4 µg/ml in the laboratory [3]. An infusion therefore contains only little dissolved curcumin.

Authorities: EMA describes turmeric rhizome for traditional herbal medicinal products as powder (0.5–1 g, 2 to 3 times daily) and tea (0.5–1 g in 150 ml boiling water). Possible side effects are mild dry mouth, flatulence and stomach irritation. It advises against use in bile duct obstruction, gallstones, liver and biliary disease, under 18 years of age, and in pregnancy and breastfeeding; EMA reports no interactions [8].

Liver: The US DILIN registry recorded ten cases of liver injury with turmeric products from 2004 to 2022; one patient died. Onset was after 1–4 months and was linked to HLA-B*35:01. All seven products analysed contained turmeric, three also piperine [9]. Another case report describes liver injury after a turmeric supplement [10].

Blood clotting: According to a review, curcumin inhibits platelet activation and aggregation, mostly in laboratory and animal experiments [11].

Health claims: For curcumin and joint function, EFSA in 2017 did not consider a cause-and-effect relationship established [12].

What this means in practice

Turmeric as a spice is far below the amounts examined in studies or in the ADI assessment. For extracts and capsules, the manufacturer's instructions apply. Anyone taking anticoagulants, liver-related drugs or other medication, with biliary problems, or who is pregnant should clarify intake with a doctor beforehand.

With gallstones or bile duct or liver disease, EMA advises against turmeric preparations [8]. If you notice yellowing of the skin, dark urine or persistent nausea, have it checked by a doctor.

Limits of this statement

The high-dose studies ran for four months at most and mostly in patients, not in healthy people. Data on intake over years are missing. The ADI assessment concerns the additive E 100. For turmeric water there are no human studies, only solubility data.

Common follow-up questions

Keep reading

• Intake guide: Bioavailability, modern formulations and the role of bioenhancers.
• Effects overview: General questions about uses of the turmeric active ingredient.
• Safety check: Safety, interactions and potential risks.
• Blood thinner focus: Interactions with blood-thinning medication.

References

• [1] EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS) (2010). Scientific Opinion on the re-evaluation of curcumin (E 100) as a food additive. EFSA Journal, 8(9):1679. DOI: 10.2903/j.efsa.2010.1679
• [2] Cheng, A. L. et al. (2001). Phase I clinical trial of curcumin, a chemopreventive agent, in patients with high-risk or pre-malignant lesions. Anticancer Research, 21(4B):2895–2900. PMID: 11712783
• [3] Kurien, B. T. et al. (2007). Improving the solubility and pharmacological efficacy of curcumin by heat treatment. Assay and Drug Development Technologies. DOI: 10.1089/adt.2007.064
• [4] Gupta, S. C., Patchva, S. & Aggarwal, B. B. (2013). Therapeutic roles of curcumin: lessons learned from clinical trials. The AAPS Journal, 15(1):195–218. DOI: 10.1208/s12248-012-9432-8
• [5] Tayyem, R. F. et al. (2006). Curcumin content of turmeric and curry powders. Nutrition and Cancer, 55(2):126–131. DOI: 10.1207/s15327914nc5502_2
• [6] Sharma, R. A. et al. (2004). Phase I clinical trial of oral curcumin: biomarkers of systemic activity and compliance. Clinical Cancer Research, 10(20):6847–6854. DOI: 10.1158/1078-0432.CCR-04-0744
• [7] Lao, C. D. et al. (2006). Dose escalation of a curcuminoid formulation. BMC Complementary and Alternative Medicine, 6:10. DOI: 10.1186/1472-6882-6-10
• [8] European Medicines Agency, HMPC (2018). European Union herbal monograph on Curcuma longa L., rhizoma (EMA/HMPC/329755/2017). ema.europa.eu
• [9] Halegoua-DeMarzio, D. et al. (2023). Liver injury associated with turmeric - a growing problem: ten cases from the Drug-Induced Liver Injury Network (DILIN). The American Journal of Medicine, 136(2):200–206. DOI: 10.1016/j.amjmed.2022.09.026
• [10] Suhail, F. K. et al. (2020). Turmeric supplement induced hepatotoxicity: a rare complication of a poorly regulated substance. Clinical Toxicology, 58(3):216–217. DOI: 10.1080/15563650.2019.1632882
• [11] Hussain, Y. et al. (2022). Regulatory effects of curcumin on platelets: an update and future directions. Biomedicines, 10(12):3180. DOI: 10.3390/biomedicines10123180
• [12] EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) (2017). Curcumin and normal functioning of joints: evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006. EFSA Journal, 15(5):4774. DOI: 10.2903/j.efsa.2017.4774

What lies behind it

Turmeric tastes fine without pepper; nobody needs piperine to use it as a spice. The question comes from bioavailability research: curcumin is poorly absorbed and quickly broken down, and piperine can inhibit this breakdown, for example glucuronidation [3]. More in the intake guide.

What the sources show

Without piperine: In healthy volunteers, no curcumin was detectable in serum after single doses of 500–8,000 mg of a curcuminoid extract, and only low amounts in two people at 10,000 and 12,000 mg [2]. Even after 2 g curcumin alone, serum levels were undetectable or very low [1].

With piperine: Together with 20 mg piperine, levels in eight healthy volunteers were clearly higher, and bioavailability rose by 2,000%. It was a small single-dose study, and no adverse effects occurred [1]. Inhibition of glucuronidation is regarded as the mechanism [1]. In the laboratory, piperine also inhibited the enzyme CYP3A selectively [6].

Safety: Isolated piperine taken as a bolus can change the absorption of several drugs, mostly increasing it. Animal studies with higher daily doses point to effects on spermatogenesis, fertility and the embryo; for pregnant women, avoiding piperine-containing supplements appears advisable [5]. According to a review, a few cases of liver injury were reported after prolonged intake of piperine together with curcumin; human trials are needed to clarify piperine's role [4]. Whether pepper as a spice acts like isolated piperine is unresolved [5].

What this means in practice

For seasoning, turmeric alone is enough. Pepper in food is a matter of taste. For capsules containing piperine, follow the manufacturer's instructions. If you take medication regularly, speak with your doctor or pharmacist before using piperine products. More in the answer on how much piperine per day.

Limits of this statement

The 2,000% comes from a single-dose study with eight healthy people and refers to 2 g curcumin. There is no such measurement for spice amounts, nor for long-term intake. No health benefit follows from it.

Common follow-up questions

Keep reading

• Intake guide: Bioavailability, modern formulations and the role of bioenhancers.
• Effects overview: General questions on effects and areas of use of the turmeric active ingredient.
• Safety check: Safety, interactions and possible risks.

References

• [1] Shoba, G. et al. (1998). Influence of piperine on the pharmacokinetics of curcumin in animals and human volunteers. Planta Medica. DOI: 10.1055/s-2006-957450
• [2] Lao, C. D. et al. (2006). Dose escalation of a curcuminoid formulation. BMC Complementary and Alternative Medicine, 6:10. DOI: 10.1186/1472-6882-6-10
• [3] Anand, P. et al. (2007). Bioavailability of curcumin: problems and promises. Molecular Pharmaceutics, 4(6):807–818. DOI: 10.1021/mp700113r
• [4] Stati, G. et al. (2021). Curcuma longa Hepatotoxicity: A Baseless Accusation. Cases Assessed for Causality Using RUCAM Method. Frontiers in Pharmacology. DOI: 10.3389/fphar.2021.780330
• [5] Ziegenhagen, R., Heimberg, K., Lampen, A. & Hirsch-Ernst, K. I. (2021). Safety Aspects of the Use of Isolated Piperine Ingested as a Bolus. Foods. DOI: 10.3390/foods10092121
• [6] Volak, L. P. et al. (2008). Curcuminoids Inhibit Multiple Human Cytochromes P450, UDP-Glucuronosyltransferase, and Sulfotransferase Enzymes, whereas Piperine Is a Relatively Selective CYP3A4 Inhibitor. Drug Metabolism and Disposition. DOI: 10.1124/dmd.108.020552

What lies behind it

The amount depends on the form: spice powder, standardised extract, or a product with absorption technology. Little curcumin is absorbed after eating; even after large amounts, only very low concentrations are detectable in blood [2]. Milligram figures from different products therefore cannot be compared directly. More in the intake guide.

What the sources show

ADI: In 2010 EFSA derived an ADI of 3 mg/kg body weight per day for curcumin as a food additive (E 100). At 70 kg this is arithmetically 210 mg. It is a toxicological reference value for an additive, not a dosing recommendation for food supplements [1].

Content in powder: In a US analysis of 28 spice products, pure turmeric powder averaged 3.14% curcumin, while curry powders contained clearly less, with large variation [3]. In India, branded powders contained 2.2–3.7% and loose powders 0.3–2.6% [4]. Arithmetically (our own calculation with 3.14%), 3 g of powder supplies about 94 mg curcumin. EMA names 0.5–1 g powder, two to three times daily, for traditional herbal medicinal products [5].

Study doses: In 18 studies in people with metabolic syndrome and related conditions, the daily curcumin amount ranged from 70 to 2,400 mg, and duration from 4 to 36 weeks [6]. Formulations differ greatly: in a crossover study in healthy volunteers, one formulation produced 45.9 times more curcuminoids in the blood than unformulated curcumin [7].

High amounts: In a study of healthy volunteers, single doses of 500–12,000 mg were given; only 7 of 24 people had minimal complaints, which were not dose-related [8]. In a phase I study of 25 patients, there was no treatment-related toxicity up to 8,000 mg/day over three months; more was unacceptable because of the volume [9].

What this means in practice

When cooking there is no fixed milligram limit. For capsules and extracts, the manufacturer's instructions apply; curcuminoid content and type of absorption technology matter, because at the same amount blood levels can differ greatly [7]. EMA advises against turmeric in gallstones and diseases of the bile ducts or liver [5].

Limits of this statement

The study doses come from patient and healthy groups, partly with single administration, and are not a recommendation. The ADI concerns the additive E 100. No health claims are authorised in the EU for curcumin. Long-term data over years are limited. If you take medication, are pregnant, have gallbladder or liver conditions, or before surgery, please check with a doctor.

Common follow-up questions

Keep reading

• Intake guide: Bioavailability, formulations and absorption barriers.
• Safety check: Side effects, risks and interactions at a glance.
• Effects overview: Overview of the researched areas of use.

References

• [1] EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS) (2010). Scientific Opinion on the re-evaluation of curcumin (E 100) as a food additive. EFSA Journal, 8(9):1679. DOI: 10.2903/j.efsa.2010.1679
• [2] Metzler, M. et al. (2013). Curcumin uptake and metabolism. BioFactors, 39(1):14–20. DOI: 10.1002/biof.1042
• [3] Tayyem, R. F. et al. (2006). Curcumin content of turmeric and curry powders. Nutrition and Cancer, 55(2):126–131. DOI: 10.1207/s15327914nc5502_2
• [4] Dixit, S. et al. (2009). Surveillance of the quality of turmeric powders from city markets of India on the basis of curcumin content and the presence of extraneous colours. Food Additives & Contaminants: Part A, 26(9):1227–1231. DOI: 10.1080/02652030903016586
• [5] European Medicines Agency, HMPC (2018). European Union herbal monograph on Curcuma longa L., rhizoma (EMA/HMPC/329755/2017). ema.europa.eu
• [6] Akbari, M. et al. (2019). The effects of curcumin on weight loss among patients with metabolic syndrome and related disorders: a systematic review and meta-analysis of randomized controlled trials. Frontiers in Pharmacology, 10:649. DOI: 10.3389/fphar.2019.00649
• [7] Jäger, R. et al. (2014). Comparative absorption of curcumin formulations. Nutrition Journal, 13:11. DOI: 10.1186/1475-2891-13-11
• [8] Lao, C. D. et al. (2006). Dose escalation of a curcuminoid formulation. BMC Complementary and Alternative Medicine, 6:10. DOI: 10.1186/1472-6882-6-10
• [9] Cheng, A. L. et al. (2001). Phase I clinical trial of curcumin, a chemopreventive agent, in patients with high-risk or pre-malignant lesions. Anticancer Research, 21(4B):2895–2900. PMID: 11712783

What lies behind it

Piperine is the main pungent compound of black pepper (Piper nigrum) [3]. In research it is studied as an additive that may improve curcumin absorption: curcumin is metabolised quickly in the liver and gut wall, and piperine inhibits glucuronidation, among other things [1]. There is no daily recommendation as there is for vitamins; the figures come from studies and regulatory assessments. More on bioavailability is in the intake guide.

What the sources show

The "20 mg" dose goes back to Shoba et al. (1998). After a single dose of 2 g curcumin, serum levels in healthy volunteers were undetectable or very low. Together with 20 mg piperine they were clearly higher, and bioavailability rose by 2,000%. No adverse effects occurred at the doses used [1]. It was a small study with a single administration; Hewlings & Kalman (2017) repeat the figure in their review [4]. Stati et al. (2021) report a few cases of liver injury after prolonged intake of the piperine-curcumin combination and call for human trials to clarify this [5].

In the laboratory, piperine inhibited human CYP3A enzymes relatively selectively (IC50 5.5 µM). This was an enzyme assay, not a study in people [6].

Ziegenhagen et al. (2021), authors at the German Federal Institute for Risk Assessment, review the data on isolated piperine [2]:

• With single or short-term administration, interactions with several drugs were seen, mostly with increased drug uptake.
• Animal studies with higher daily doses point to disturbed spermatogenesis and to harm to fertility and the embryo; meaningful human data are lacking. For pregnant women, avoiding piperine-containing supplements appears advisable.
• In 2015 EFSA derived a NOAEL of 5 mg/kg body weight per day from a 90-day rat study (endpoint: cholesterol increase in male animals). As a flavouring, it saw no safety concern at the estimated intakes [2, 7].
• For isolated piperine taken as a bolus, the authors calculate a health-based guidance value of about 2.3 mg per day. This is their own calculation, not an official limit.
• Australia recommended at most 10 mg per day for medicinal preparations, and Health Canada names at most 14 mg per day. Food supplements often contain 5–30 mg per daily dose.

Piperine from food: pepper contains about 2–9% piperine. The BfR estimated in 2018 for men in Germany 24–36 mg piperine per day on average and 64–96 mg at the 95th percentile, with considerable uncertainty [2]. Whether pepper as a spice influences curcumin absorption as strongly as isolated piperine is unresolved. Other pepper constituents and how finely it is ground may play a role [2].

What this means in practice

No generally valid daily amount can be derived from the sources. The 20 mg come from a short-term study, the regulatory values are lower, and data on long-term intake of isolated piperine are lacking [2].

Piperine can change how drugs are absorbed [2]. If you take medication regularly, speak with your doctor or pharmacist before using a piperine product.

Limits of this statement

The human data come from small short-term studies in healthy adults. The NOAEL is based on rat data, and the reproductive findings also come from animal studies. For children, pregnant or breastfeeding women, and people with existing conditions or medication, the data are not robust enough; the decision belongs with a doctor. More under Curcumin side effects.

Common follow-up questions

Keep reading

• Intake guide: Bioavailability, formulations and the role of bioenhancers.
• Safety check: Safety, interactions and possible risks.
• Effects overview: Fields of application of the turmeric active ingredient in research.
• Piperine guide: Piperine and possible interactions with medications.

References

• [1] Shoba, G. et al. (1998). Influence of piperine on the pharmacokinetics of curcumin in animals and human volunteers. Planta Medica. DOI: 10.1055/s-2006-957450
• [2] Ziegenhagen, R., Heimberg, K., Lampen, A. & Hirsch-Ernst, K. I. (2021). Safety Aspects of the Use of Isolated Piperine Ingested as a Bolus. Foods. DOI: 10.3390/foods10092121
• [3] Gorgani, L. et al. (2017). Piperine—The Bioactive Compound of Black Pepper: From Isolation to Medicinal Formulations. Comprehensive Reviews in Food Science and Food Safety. DOI: 10.1111/1541-4337.12246
• [4] Hewlings, S. J. & Kalman, D. S. (2017). Curcumin: A Review of Its Effects on Human Health. Foods. DOI: 10.3390/foods6100092
• [5] Stati, G. et al. (2021). Curcuma longa Hepatotoxicity: A Baseless Accusation. Cases Assessed for Causality Using RUCAM Method. Frontiers in Pharmacology. DOI: 10.3389/fphar.2021.780330
• [6] Volak, L. P. et al. (2008). Curcuminoids Inhibit Multiple Human Cytochromes P450, UDP-Glucuronosyltransferase, and Sulfotransferase Enzymes, whereas Piperine Is a Relatively Selective CYP3A4 Inhibitor. Drug Metabolism and Disposition. DOI: 10.1124/dmd.108.020552
• [7] EFSA CEF Panel (2015). Scientific Opinion on Flavouring Group Evaluation 86, Revision 2 (FGE.86Rev2). EFSA Journal. DOI: 10.2903/j.efsa.2015.3998

What lies behind it

Turmeric juice is pressed from the fresh root. The active compound curcumin dissolves poorly in water [1]; how much of it passes into an aqueous juice and how much stays in the pulp, we found in no source. For orientation: in one analysis, turmeric powder (dried root) contained on average 3.14 % curcumin by weight [2].

What the sources show

We found no study that examined turmeric juice in defined amounts, so a recommendation in millilitres cannot be backed up.

For the isolated compound curcumin (food additive E 100), EFSA derived an ADI (acceptable daily intake) of 3 mg per kg body weight; intake from the normal diet is below 7 % of the ADI [3]. For 70 kg this is 210 mg of curcumin per day by calculation.

For tolerability of higher amounts there are studies with curcumin capsules: in a phase I study of 25 patients with pre-malignant conditions, no treatment-related toxicity occurred up to 8,000 mg of curcumin daily for three months [4]. In 24 healthy volunteers, single doses of 500 to 12,000 mg caused only minor, non-dose-related complaints [5]. These results concern capsules, not juice.

What this means in practice

Turmeric juice is a food; there is no evidence-based upper or lower limit. No juice amount can be derived from the capsule studies. If you take medication or have biliary problems, talk to a doctor before regularly drinking larger amounts.

Limits of this statement

The figures come from studies with capsules, partly in patients, partly with single doses. For fresh juice, additions such as black pepper or ginger, and long-term consumption, the sources checked contain no data.

Frequently asked follow-up questions

Read more

Want to dive deeper into the subject? Continue here:

• Intake guide: How water solubility and the first-pass effect control absorption.
• Safety check: What risks and interactions exist with additives such as piperine.

References

• [1] Zheng, B. & McClements, D. J. (2020). Formulation of more efficacious curcumin delivery systems using colloid science: enhanced solubility, stability, and bioavailability. Molecules. DOI: 10.3390/molecules25122791
• [2] Tayyem, R. F. et al. (2006). Curcumin content of turmeric and curry powders. Nutrition and Cancer. DOI: 10.1207/s15327914nc5502_2
• [3] EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS) (2010). Scientific Opinion on the re-evaluation of curcumin (E 100) as a food additive. EFSA Journal 8(9):1679. DOI: 10.2903/j.efsa.2010.1679
• [4] Cheng, A. L. et al. (2001). Phase I clinical trial of curcumin, a chemopreventive agent, in patients with high-risk or pre-malignant lesions. Anticancer Research 21(4B):2895–2900. PMID: 11712783
• [5] Lao, C. D. et al. (2006). Dose escalation of a curcuminoid formulation. BMC Complementary and Alternative Medicine. DOI: 10.1186/1472-6882-6-10

What lies behind it

Three different things stand behind the question: turmeric as a spice powder (ground root), isolated curcumin as the food colour E 100, and capsules with extracts. There is a regulatory reference value for the isolated colour, but not for spice powder.

What the sources show

ADI. EFSA re-evaluated curcumin (E 100) and derived an ADI of 3 mg per kg body weight per day; an earlier value was 0–3 mg/kg. For 70 kg this is 210 mg of curcumin per day by calculation. Intake from the normal diet is below 7 % of the ADI [1].

Curcumin content of the powder. One analysis found an average of 3.14 % curcumin by weight in pure turmeric powder; curry powder contained much less and varied widely [2]. An Indian survey found 2.2–3.7 % curcumin in branded powders and 0.3–2.6 % in loose goods, and an unapproved colour in 17 % of the loose samples [3]. By calculation, 3 g of powder at 3.14 % contain about 94 mg of curcumin; a level teaspoon is roughly 2 to 3 g (household estimate, no study source). For 500 mg of curcumin, about 16 g of powder would be needed by calculation.

Study doses. These amounts are far below what was given in studies with extracts and capsules:

• 15 patients with advanced colorectal cancer received 440 to 2,200 mg of Curcuma extract daily (36–180 mg curcumin) for up to four months; no dose-limiting toxicity was observed [4].
• In another study of 15 patients, 0.45 to 3.6 g of curcumin daily was given for up to four months, again without dose-limiting toxicity [5].
• In 24 healthy volunteers, single doses of 500 to 12,000 mg were given; seven people had minor, non-dose-related complaints [6].
• In 25 patients with pre-malignant conditions, no treatment-related toxicity occurred up to 8,000 mg daily for three months [7].

What this means in practice

Spice amounts of a few grams per day are, by calculation, far below the ADI for curcumin. The study doses are not an intake recommendation. For capsules, the manufacturer's stated daily amount applies. If you take medication, have biliary problems or are about to have surgery, talk to a doctor first.

Limits of this statement

The ADI is a regulatory value for the additive, not a dosing recommendation. The studies partly involved patients, partly single doses, and extracts rather than spice powder. The curcumin content of kitchen powder cannot be determined without laboratory analysis. The sources checked contain no data on long-term intake of high amounts.

Frequently asked follow-up questions

Further reading

• Intake guide: Bioavailability, formulations and the first-pass effect.
• Bioavailability: Which formulations achieve higher blood levels in studies.
• Safety check: Side effects, risks and the safety profile at a glance.
• Quality check: How to recognise high-quality turmeric powder.
• Kitchen tips: Using turmeric in everyday cooking.
• Effects overview: Overview of the researched areas of use.

References

• [1] EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS) (2010). Scientific Opinion on the re-evaluation of curcumin (E 100) as a food additive. EFSA Journal 8(9):1679. DOI: 10.2903/j.efsa.2010.1679
• [2] Tayyem, R. F. et al. (2006). Curcumin content of turmeric and curry powders. Nutrition and Cancer. DOI: 10.1207/s15327914nc5502_2
• [3] Dixit, S. et al. (2009). Surveillance of the quality of turmeric powders from city markets of India on the basis of curcumin content and the presence of extraneous colours. Food Additives & Contaminants: Part A 26(9):1227–1231. DOI: 10.1080/02652030903016586
• [4] Sharma, R. A. et al. (2001). Pharmacodynamic and pharmacokinetic study of oral Curcuma extract in patients with colorectal cancer. Clinical Cancer Research 7(7):1894–1900. PMID: 11448902
• [5] Sharma, R. A. et al. (2004). Phase I clinical trial of oral curcumin: biomarkers of systemic activity and compliance. Clinical Cancer Research. DOI: 10.1158/1078-0432.CCR-04-0744
• [6] Lao, C. D. et al. (2006). Dose escalation of a curcuminoid formulation. BMC Complementary and Alternative Medicine. DOI: 10.1186/1472-6882-6-10
• [7] Cheng, A. L. et al. (2001). Phase I clinical trial of curcumin, a chemopreventive agent, in patients with high-risk or pre-malignant lesions. Anticancer Research 21(4B):2895–2900. PMID: 11712783

What lies behind it

Piperine is the main pungent compound of black pepper (Piper nigrum) [1]. After ingestion, curcumin is poorly absorbed and is rapidly converted in the liver and gut wall. Piperine inhibits enzymes involved in this conversion.

What the sources show

In a small study of healthy volunteers, blood levels of curcumin after 2 g of curcumin alone were undetectable or very low. When 20 mg of piperine was added, levels were clearly higher; the authors calculated a 2,000 % increase in bioavailability, and no adverse effects were reported [2]. This is the result of a single, small study.

As for the mechanism: in rat liver and after oral dosing in rats, piperine inhibited drug-metabolising enzymes, including a glucuronidation reaction [3]. In laboratory experiments with human enzymes, piperine mainly inhibited CYP3A, an important enzyme for breaking down many drugs [4]. Inhibition of the transport protein P-glycoprotein has also been described [5].

Whether this matters in humans is shown by interaction studies with small numbers of participants:

• Five healthy volunteers took 20 mg of piperine daily for 7 days; afterwards the antiepileptic phenytoin reached higher blood levels (larger area under the concentration curve) and a longer half-life [6].
• In 20 healthy volunteers, three days of pretreatment with 15 mg piperine prolonged the half-life of the sedative midazolam and the duration of sedation [7].
• In contrast, a combination of 4 g curcuminoids and 24 mg piperine given over 2 days did not meaningfully change blood levels of midazolam, flurbiprofen or paracetamol in eight healthy volunteers [8].

What this means in practice

In the studies, piperine was taken at the same time as the curcumin, in amounts of 15 to 24 mg; these are study doses, not an intake recommendation. If you take medicines regularly, especially ones with a narrow therapeutic range, talk to your doctor or pharmacist before taking piperine. Which interactions occur cannot be derived from a single study.

Limits of this statement

The studies include only 5 to 20 participants, in part single or short-term doses. Some of the enzyme inhibition data come from rat and laboratory experiments. The sources used here contain no long-term data on continuous piperine intake or on health effects. How much piperine you take in through culinary pepper cannot be quantified from these sources.

Frequently asked follow-up questions

Read further

Want to go deeper into the subject? Here's where to continue:

• Intake guide: Everything about bioavailability, modern formulations and the role of piperine.
• Safety check: A detailed look at safety, interactions and potential risks.
• Effects overview: Answers to general questions about effects and areas of research.
• Medication focus: Specific information on piperine and its interactions with medicines.

References

• [1] Gorgani, L. et al. (2017). Piperine—The Bioactive Compound of Black Pepper: From Isolation to Medicinal Formulations. Comprehensive Reviews in Food Science and Food Safety. DOI: 10.1111/1541-4337.12246
• [2] Shoba, G. et al. (1998). Influence of piperine on the pharmacokinetics of curcumin in animals and human volunteers. Planta Medica. DOI: 10.1055/s-2006-957450
• [3] Atal, C. K. et al. (1985). Biochemical basis of enhanced drug bioavailability by piperine: evidence that piperine is a potent inhibitor of drug metabolism. Journal of Pharmacology and Experimental Therapeutics. DOI: 10.1016/s0022-3565(25)20081-7
• [4] Volak, L. P. et al. (2008). Curcuminoids inhibit multiple human cytochromes P450, UDP-glucuronosyltransferase, and sulfotransferase enzymes, whereas piperine is a relatively selective CYP3A4 inhibitor. Drug Metabolism and Disposition. DOI: 10.1124/dmd.108.020552
• [5] Bhardwaj, R. K. et al. (2002). Piperine, a major constituent of black pepper, inhibits human P-glycoprotein and CYP3A4. Journal of Pharmacology and Experimental Therapeutics. DOI: 10.1124/jpet.102.034728
• [6] Bano, G. et al. (1987). The effect of piperine on pharmacokinetics of phenytoin in healthy volunteers. Planta Medica. DOI: 10.1055/s-2006-962814
• [7] Rezaee, M. M. et al. (2014). The effect of piperine on midazolam plasma concentration in healthy volunteers, a research on the CYP3A-involving metabolism. DARU Journal of Pharmaceutical Sciences. DOI: 10.1186/2008-2231-22-8
• [8] Volak, L. P. et al. (2013). Effect of a herbal extract containing curcumin and piperine on midazolam, flurbiprofen and paracetamol (acetaminophen) pharmacokinetics in healthy volunteers. British Journal of Clinical Pharmacology. DOI: 10.1111/j.1365-2125.2012.04364.x

What's behind it

Curcumin is a fat-soluble plant compound. It barely dissolves in water, is chemically not very stable and is rapidly converted in the body, so only a small part of ingested curcumin reaches the bloodstream [1]. This raises the question of whether fat improves absorption.

What the sources show

For cooking oil or fatty meals we found no human study with reliable figures. What has been shown is that formulations that embed curcumin in fat or lipid structures increase absorption:

• In a randomised, double-blind crossover study in humans, absorption of curcuminoids from a lecithin formulation (Meriva) was about 29-fold higher than from the unformulated mixture. Only metabolites were detectable, and blood levels remained low [2].
• In a crossover study of 23 healthy people (single dose of 500 mg curcuminoids), availability from liquid micelles was 277-fold (women), 114-fold (men) and 185-fold (all) higher than from native powder, and 14-, 5- and 9-fold higher from micronised powder. Women absorbed curcumin more efficiently than men [3].

These factors apply to these specific products and not to turmeric powder in oil. A review on the food matrix reports that lipids improve the stability and bioavailability of spice compounds and that dairy-rich systems markedly enhance the bioavailability of lipophilic compounds such as curcuminoids; however, the human studies are mostly acute studies [4]. Reviews list encapsulation in micelles, liposomes, emulsions or lipid particles as ways of improving absorption [1]. Piperine from black pepper also raised curcumin levels in a small study (2 g curcumin plus 20 mg piperine: 2,000 % higher bioavailability) [5].

What this means in practice

Using turmeric with some fat is common in cooking and plausible because curcumin is fat-soluble. How large the effect is with cooking oil cannot be quantified from the sources. If you take capsules, follow the manufacturer's instructions.

Limits of this statement

All figures come from small studies with single doses in healthy people and from special formulations. Higher blood levels do not automatically mean a health effect. Piperine can also affect medicines. If you have biliary conditions or take medication, talk to a doctor first.

Frequently asked follow-up questions

Read more

Want to dive deeper into the subject? Continue here:

• Intake guide: How micelles, lipids and the first-pass effect control absorption.
• Safety check: What risks exist with highly bioavailable preparations.
• Effects overview: A comprehensive overview of the various application areas.

References

• [1] Zheng, B. & McClements, D. J. (2020). Formulation of more efficacious curcumin delivery systems using colloid science: enhanced solubility, stability, and bioavailability. Molecules. DOI: 10.3390/molecules25122791
• [2] Cuomo, J. et al. (2011). Comparative absorption of a standardized curcuminoid mixture and its lecithin formulation. Journal of Natural Products. DOI: 10.1021/np1007262
• [3] Schiborr, C. et al. (2014). The oral bioavailability of curcumin from micronized powder and liquid micelles is significantly increased in healthy humans and differs between sexes. Molecular Nutrition & Food Research. DOI: 10.1002/mnfr.201300724
• [4] Rak, K. et al. (2026). Food matrix as a modulator of spice phytochemical bioactivity: evidence from in vitro, animal, and human studies. Nutrients 18(18):3048. DOI: 10.3390/nu18183048
• [5] Shoba, G. et al. (1998). Influence of piperine on the pharmacokinetics of curcumin in animals and human volunteers. Planta Medica. DOI: 10.1055/s-2006-957450

What lies behind it

Turmeric and ginger are often used together. Turmeric contains curcuminoids, ginger contains gingerols. For both it matters whether you take them as a spice or as an extract in capsules, because the amounts differ greatly. More on the absorption of curcumin can be found in our intake guide.

What the sources show

Turmeric. EFSA re-evaluated curcumin (E 100) as a food additive and derived an ADI (acceptable daily intake) of 3 mg per kg body weight per day; an earlier value was 0–3 mg/kg [1]. For 70 kg this is 210 mg of curcumin per day by calculation. EFSA also noted that intake from the normal diet is below 7 % of the ADI [1]. In an analysis of spice products, pure turmeric powder contained on average 3.14 % curcumin by weight, curry powders much less and highly variable amounts [2]. By calculation, 3 g of turmeric powder therefore contain about 94 mg of curcumin.

Studies with much higher curcumin amounts: in 24 healthy volunteers, single doses of 500 to 12,000 mg were given; seven people had minor complaints that were not dose-related [3]. In a study of 15 patients with advanced colorectal cancer, 0.45 to 3.6 g of curcumin daily were taken for up to four months; no dose-limiting toxicity was observed [4]. A review rated six human trials as safe, including a phase I study with up to 8,000 mg of curcumin daily for three months [5].

Ginger. We found no source with an official maximum daily amount for ginger. An umbrella review of 24 systematic reviews reports that studies mostly used 0.5 to 3 g per day in capsule form for up to three months, and concludes that dietary ginger appears safe [6]. In a study with 27 volunteers, single doses of 100 mg to 2 g ginger were examined; in blood, gingerols appeared only as glucuronide and sulfate conjugates [7]. For blood clotting the data are mixed: of eight clinical trials, four reported reduced platelet aggregation with ginger and four reported no effect [8].

What this means in practice

Usual spice amounts are, by calculation, far below the ADI for curcumin. For capsules, follow the manufacturer's stated daily amount. The study doses mentioned are not an intake recommendation. If you take anticoagulants, talk to your doctor first, as the effect of ginger on clotting is not clearly established [8].

Limits of this statement

The curcumin studies partly involved patients and partly single doses. No study of the combination of turmeric and ginger is available in our sources. The data are not designed for pregnant or breastfeeding women or people with pre-existing conditions.

Frequently asked follow-up questions

Read further

Want to go deeper into the subject? Here's where to continue:

• Intake guide: Detailed information on bioavailability, modern formulations and the role of dietary fats.
• Safety check: An overview of safety, potential side effects and risk groups.
• Effects overview: Answers to general questions about effects and areas of use of the active ingredient in turmeric.
• Medication focus: Important information on interactions between curcumin and medicines.

References

• [1] EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS) (2010). Scientific Opinion on the re-evaluation of curcumin (E 100) as a food additive. EFSA Journal 8(9):1679. DOI: 10.2903/j.efsa.2010.1679
• [2] Tayyem, R. F. et al. (2006). Curcumin content of turmeric and curry powders. Nutrition and Cancer. DOI: 10.1207/s15327914nc5502_2
• [3] Lao, C. D. et al. (2006). Dose escalation of a curcuminoid formulation. BMC Complementary and Alternative Medicine. DOI: 10.1186/1472-6882-6-10
• [4] Sharma, R. A. et al. (2004). Phase I clinical trial of oral curcumin: biomarkers of systemic activity and compliance. Clinical Cancer Research. DOI: 10.1158/1078-0432.CCR-04-0744
• [5] Chainani-Wu, N. (2003). Safety and anti-inflammatory activity of curcumin: a component of tumeric (Curcuma longa). Journal of Alternative and Complementary Medicine. DOI: 10.1089/107555303321223035
• [6] Crichton, M. et al. (2022). Orally consumed ginger and human health: an umbrella review. American Journal of Clinical Nutrition. DOI: 10.1093/ajcn/nqac035
• [7] Zick, S. M. et al. (2008). Pharmacokinetics of 6-gingerol, 8-gingerol, 10-gingerol, and 6-shogaol and conjugate metabolites in healthy human subjects. Cancer Epidemiology, Biomarkers & Prevention. DOI: 10.1158/1055-9965.EPI-07-2934
• [8] Marx, W. et al. (2015). The effect of ginger (Zingiber officinale) on platelet aggregation: a systematic literature review. PLoS ONE. DOI: 10.1371/journal.pone.0141119

What lies behind it

Curcumin is fat-soluble and poorly absorbed. Timing was not examined directly in the studies reviewed: they compare neither morning with evening nor fasted with fed. Differences between formulations are, however, documented. More in the intake guide.

What the sources show

Food: A review on spices concludes that lipids, proteins and dietary fibre improve the stability and bioavailability of spice constituents. Dairy-rich systems clearly increased the bioavailability of fat-soluble compounds such as curcuminoids. Most human studies were acute studies [1].

Fasted or with a meal: In the study by Jäger et al. (2014), healthy volunteers took a single dose with water after a 10-hour fast; a turmeric-free meal followed only after four hours. One formulation with a hydrophilic carrier reached 45.9-fold higher absorption than unformulated curcumin [2]. The authors point out that another study (Cuomo et al.) gave the capsule with a high-fat meal, which could improve absorption of fat-soluble ingredients [2]. That is the authors' interpretation, not a measured comparison. A lecithin formulation raised absorption about 29-fold versus a curcuminoid mixture [3], and another formulation (BCM-95CG) about 6.9-fold versus normal curcumin [4].

Spreading over the day: For turmeric powder in traditional herbal medicinal products, EMA describes 0.5–1 g two to three times daily, and tea from 0.5–1 g in 150 ml boiling water. Mild stomach irritation, dry mouth and flatulence may occur. It makes no statement on time of day [5].

What this means in practice

The sources do not imply a fixed time. A reasonable approach is to use turmeric spice in food, for example in dishes with oil or dairy, and to take capsules according to the manufacturer's instructions. If capsules upset your stomach, take them with a meal; that is a precaution, not a study finding. A regular time mainly helps you not to forget.

Limits of this statement

The statements on fat come from a review and from study authors' interpretation, not from a direct comparison of fasted and fed intake. The formulation studies were single-dose studies in healthy people. In gallstones or diseases of the bile ducts and liver, EMA advises against turmeric [5]. Please clarify medication use and pregnancy with a doctor.

Common follow-up questions

Keep reading

• Intake guide: Bioavailability, modern formulations and the role of bioenhancers.
• Safety check: Safety, interactions and potential risks.
• Effects overview: General questions on effects and areas of use in research.

References

• [1] Rak, K., Serek, P., Sławińska, P. & Raczkowska, E. (2026). Food Matrix as a Modulator of Spice Phytochemical Bioactivity: Evidence from In Vitro, Animal, and Human Studies. Nutrients, 18(18):3048. DOI: 10.3390/nu18183048
• [2] Jäger, R. et al. (2014). Comparative absorption of curcumin formulations. Nutrition Journal, 13:11. DOI: 10.1186/1475-2891-13-11
• [3] Cuomo, J. et al. (2011). Comparative absorption of a standardized curcuminoid mixture and its lecithin formulation. Journal of Natural Products, 74(4):664–669. DOI: 10.1021/np1007262
• [4] Antony, B. et al. (2008). A pilot cross-over study to evaluate human oral bioavailability of BCM-95CG (Biocurcumax), a novel bioenhanced preparation of curcumin. Indian Journal of Pharmaceutical Sciences, 70(4):445–449. DOI: 10.4103/0250-474X.44591
• [5] European Medicines Agency, HMPC (2018). European Union herbal monograph on Curcuma longa L., rhizoma (EMA/HMPC/329755/2017). ema.europa.eu

What lies behind it

Curcumin is fat-soluble, poorly absorbed and rapidly converted [4]. This raises the question of whether taking it without a meal has disadvantages.

What the sources show

We found no human study in the sources checked that compares the same amount of curcumin taken fasted and with a meal. Indirect evidence:

• A review on the food matrix reports that lipids improve the stability and bioavailability of spice compounds and that dairy-rich systems markedly enhance the bioavailability of lipophilic compounds such as curcuminoids. The human studies are mostly acute studies [1].
• Formulations that embed curcumin increased absorption in crossover studies in healthy people: a lecithin formulation about 29-fold versus the unformulated mixture [2]; liquid micelles 185-fold and micronised powder 9-fold versus native powder (single dose of 500 mg) [3]. A review collects eleven such formulations with higher bioavailability than unformulated curcumin [4].

These studies do not show whether the participants were fasted or how strongly a meal affects the respective products.

What this means in practice

Because curcumin is fat-soluble, taking it with a meal is a reasonable idea, but a concrete advantage over fasted intake has not been shown for capsules. For an individual product, the manufacturer's instructions apply. If you are sensitive to supplements, taking them with a meal may be practical; we found no study on this.

Limits of this statement

A direct fasted-versus-meal comparison is missing. The figures apply to specific products, single doses and healthy people. Higher blood levels do not automatically mean a health benefit. If you have biliary conditions or take medication, talk to a doctor first.

Frequently asked follow-up questions

Read more

Want to dive deeper into the subject? Continue here:

• Intake guide: Worth knowing about bioavailability, modern formulations and the role of bioenhancers.
• Safety check: A detailed look at safety, interactions and potential risks.
• Effects overview: Answers to general questions about effects and application areas in research.

References

• [1] Rak, K. et al. (2026). Food matrix as a modulator of spice phytochemical bioactivity: evidence from in vitro, animal, and human studies. Nutrients 18(18):3048. DOI: 10.3390/nu18183048
• [2] Cuomo, J. et al. (2011). Comparative absorption of a standardized curcuminoid mixture and its lecithin formulation. Journal of Natural Products. DOI: 10.1021/np1007262
• [3] Schiborr, C. et al. (2014). The oral bioavailability of curcumin from micronized powder and liquid micelles is significantly increased in healthy humans and differs between sexes. Molecular Nutrition & Food Research. DOI: 10.1002/mnfr.201300724
• [4] Jamwal, R. (2018). Bioavailable curcumin formulations: a review of pharmacokinetic studies in healthy volunteers. Journal of Integrative Medicine. DOI: 10.1016/j.joim.2018.07.001

What lies behind it

Curcumin has low oral bioavailability: it is poorly absorbed, rapidly converted and quickly eliminated [1]. Capsule products therefore differ greatly in the type and amount of extract and in formulation.

What the sources show

A review on the food matrix reports that lipids improve the stability and bioavailability of spice compounds and that dairy-rich systems markedly enhance the bioavailability of lipophilic compounds such as curcuminoids. The human studies are mostly acute studies [2].

On formulations: in a human crossover study, absorption from a lecithin formulation was about 29-fold higher than from the unformulated curcuminoid mixture, but blood levels remained low [3]. In 23 healthy people (single dose of 500 mg curcuminoids), availability from liquid micelles was 185-fold and from micronised powder 9-fold higher than from native powder [4]. A review collects eleven formulations with higher bioavailability than unformulated curcumin [5].

For the best time of day (fasted, before or after a meal), for chewing versus swallowing, and for splitting into several doses, we found no studies in the sources checked.

What this means in practice

Follow the intake instructions on the label; they are matched to the specific product, and the daily amount stated by the manufacturer should not be exceeded. Whether taking capsules with a meal has practical advantages has not been studied directly; since curcumin is fat-soluble, it is a reasonable idea.

Limits of this statement

The figures come from small studies with single doses in healthy people and apply only to the respective products. Higher blood levels do not automatically mean a health effect. If you take medication, have biliary problems, are pregnant or breastfeeding, talk to a doctor before taking it.

Frequently asked follow-up questions

Read more

Want to dive deeper into the subject? Continue here:

• Intake guide: Worth knowing about bioavailability, modern formulations and the role of bioenhancers.
• Safety check: A detailed look at safety, interactions and potential risks.
• Effects overview: Answers to general questions about effects and application areas of the turmeric active ingredient.

References

• [1] Anand, P. et al. (2007). Bioavailability of curcumin: problems and promises. Molecular Pharmaceutics. DOI: 10.1021/mp700113r
• [2] Rak, K. et al. (2026). Food matrix as a modulator of spice phytochemical bioactivity: evidence from in vitro, animal, and human studies. Nutrients 18(18):3048. DOI: 10.3390/nu18183048
• [3] Cuomo, J. et al. (2011). Comparative absorption of a standardized curcuminoid mixture and its lecithin formulation. Journal of Natural Products. DOI: 10.1021/np1007262
• [4] Schiborr, C. et al. (2014). The oral bioavailability of curcumin from micronized powder and liquid micelles is significantly increased in healthy humans and differs between sexes. Molecular Nutrition & Food Research. DOI: 10.1002/mnfr.201300724
• [5] Jamwal, R. (2018). Bioavailable curcumin formulations: a review of pharmacokinetic studies in healthy volunteers. Journal of Integrative Medicine. DOI: 10.1016/j.joim.2018.07.001