Last reviewed on 8 October 2026.
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Curcumin is the main yellow pigment in turmeric, the dried rhizome of Curcuma longa that Indian kitchens know as haldi. The two words are not interchangeable. Turmeric is the whole spice; curcumin is one family of compounds inside it, making up roughly 3 per cent of a good powder by weight. Supplements concentrate that fraction many times over, and the trials people quote for joint pain tested those concentrates at about 1,000 mg of curcumin a day, not a spoon of spice. This entry, part of the supplements section of the handbook, covers the content, the absorption problem, the evidence and the two safety questions that matter in India: the liver and lead.
What is curcumin, and how does it differ from turmeric?
Turmeric is a plant of the ginger family, and curcumin is the component that gives its rhizome the yellow colour. The compounds usually credited with turmeric's biological activity are the curcuminoids, of which curcumin is the principal one. Indian regulation treats the same plant in two ways: as a spice with a purity standard and as a botanical ingredient in health supplements. The nutrient profile of the spice itself is on this site's turmeric food table.
How much curcumin is in haldi powder?
About 3 per cent in a pure powder, and less in blends. A laboratory survey published in 2006 measured 28 spice products sold as turmeric or curry powder. Pure turmeric powder had the highest concentration, averaging 3.14 per cent curcumin by weight, while curry powders held relatively small and highly variable amounts. In India, FSSAI's standard for haldi powder sets a floor: its colouring power, expressed as curcuminoid content on a dry basis, must be at least 2.0 per cent by weight.
| Form | Curcumin or curcuminoids | Source of the figure |
|---|---|---|
| Pure turmeric powder | 3.14 per cent by weight on average | Laboratory survey of spice products, 2006 |
| Haldi powder meeting the Indian standard | At least 2.0 per cent curcuminoids, dry basis | FSSAI food product standards |
| Curry powder blends | Small and highly variable | The same 2006 survey |
| 3 g of turmeric powder | 60 mg at 2 per cent; about 94 mg at 3.14 per cent | Arithmetic from the two figures above |
| Extracts used in arthritis trials | About 1,000 mg of curcumin a day | 2016 meta-analysis of randomised trials |
The gap between the fourth row and the fifth is the main thing to hold on to. Research on curcumin extracts tells you about extracts. It says very little about the haldi in sambar, khichdi or a glass of turmeric milk, because the amounts differ about tenfold and the body absorbs little of either.
The Indian position: a spice standard, a supplement schedule and no ICMR-NIN requirement
ICMR-NIN sets no requirement for curcumin, since it is not a nutrient. The Dietary Guidelines for Indians (2024) mention turmeric once in this context, listing it among spices that are rich in antioxidants and could be part of a balanced diet. They make no recommendation about curcumin supplements. The binding rules are FSSAI's, and they sit in three separate regulations.
| Regulation | Provision |
|---|---|
| Food product standards, turmeric (haldi) powder | At least 2.0 per cent curcuminoids; free from added colouring matter including lead chromate; test for lead chromate negative |
| Contaminants, toxins and residues | Lead in turmeric, whole and powder: not more than 10 parts per million |
| Health supplements, Schedule IV | Curcuma longa rhizome: 1 to 3 g a day as powder for adults |
| Health supplements, Schedule VI | Lists standardised Curcuma longa extract and curcuminoids as nutraceutical ingredients; piperine from pepper extract at 15 mg a day at most, for no more than 30 days |
| Health supplements, definitions | Turmeric as a plain spice, cleaned, dried or powdered, is not a health supplement |
Read together, these draw a clear line. Haldi sold as a spice is a food and has to meet the purity standard. A capsule of curcuminoid extract is a nutraceutical and has to meet the labelling rules described further down. The schedule's 30-day limit on piperine is worth noticing, because many curcumin capsules add piperine and are sold for continuous use.
Why is curcumin poorly absorbed, and what does piperine change?
Curcumin is broken down quickly in the liver and the gut wall, so very little reaches the blood unchanged. A much-cited 1998 study from St John's Medical College, Bangalore, gave healthy volunteers 2 g of curcumin: serum levels were either undetectable or very low. When the same amount was given with 20 mg of piperine, the pungent compound in black pepper, blood concentrations were much higher for the first hour and bioavailability rose by 2,000 per cent. The authors explain this by piperine's inhibition of the process that clears curcumin.
Three cautions belong with that famous figure. A 2,000 per cent rise from a starting point near zero is still a small absolute amount, and the higher levels lasted about an hour. The 20 mg of piperine used is more than the 15 mg a day that FSSAI's schedule permits in a nutraceutical. And higher absorption is not automatically a benefit: the researchers who described the recent liver injury cases suggest that added pepper may be part of the explanation.
What does the evidence say about osteoarthritis?
It says curcumin extracts probably ease knee pain somewhat over a few weeks, and that the trials are too small and too mixed to be sure. A 2016 systematic review found 8 eligible randomised trials. The pooled pain score fell by 2.04 points against placebo in the three trials that reported it, and in five trials the result did not differ significantly from pain medicines. The authors nonetheless wrote that the number of trials, the total sample and the quality of the studies were not sufficient to draw definitive conclusions. The lead author declared that he heads a company making dietary supplements.
A larger 2021 meta-analysis pooled 15 trials with 1,621 participants and reported less pain and stiffness and better function than placebo, effects similar to anti-inflammatory painkillers, and no more adverse events than placebo. Its authors declared no funding. The preparations it combined ranged from 40 mg of one branded formulation to 1,500 mg of another, which makes a single effective amount impossible to state. NCCIH, the United States government's centre for complementary health research, summarises the field as initially positive, with higher-quality evidence needed. This site's article on an Indian diet approach to arthritis places the question in the wider diet.
Beyond the joints, claims run far ahead of data. NCCIH states that there is not enough evidence to conclude definitively whether turmeric or curcumin is beneficial for any health purpose, including fatty liver and cholesterol, where early studies exist. Curcumin is not a treatment for arthritis or any other disease, and it does not replace a prescribed medicine.
Liver injury, side effects and who should see a doctor first
Ordinary side effects are digestive. NCCIH lists nausea, vomiting, acid reflux, stomach upset, diarrhoea and constipation, and describes conventionally formulated turmeric or curcumin as likely safe in recommended amounts for up to two or three months. The serious concern is liver injury, which has been reported with supplements and not with turmeric used in cooking.
The clearest account comes from the United States Drug-Induced Liver Injury Network, a research programme funded by the National Institutes of Health. Reviewing cases recorded from 2004 to 2022, it found ten in which turmeric was implicated, all since 2011 and six since 2017. Eight were women and the median age was 56. Injury began one to four months after starting. Five people were admitted to hospital and one died of acute liver failure. Of seven products tested, three also contained piperine. Seven patients carried the same immune gene variant, HLA-B*35:01, which suggests that susceptibility is partly inherited and cannot be predicted from the label.
Ten cases over many years, in a country where turmeric supplements are widely taken, describes a rare event. It is still a reason to treat a concentrated capsule with more respect than the spice. The site's guide to eating with fatty liver explains why people with existing liver disease should be especially wary of herbal concentrates.
Stop the supplement and see a doctor without delay if you develop unusual tiredness, nausea, poor appetite, dark urine or yellowing of the eyes or skin. Those are the warning signs NCCIH names. Nothing in these reports is a reason to cook without turmeric.
Lead chromate in haldi: what Indian market surveys found
The larger public health problem with turmeric in India is not the supplement but the spice. Lead chromate, a bright yellow industrial pigment, is added to roots and powder to improve their colour. A survey of 356 samples from 23 cities in India, Pakistan, Sri Lanka and Nepal, collected between December 2020 and March 2021, found detectable lead above 2 micrograms per gram in 14 per cent, with levels above 1,000 micrograms per gram in Patna.
A follow-up study of 503 samples from 34 cities in Bihar, Jharkhand, Uttar Pradesh, West Bengal and Chhattisgarh, collected from 2021 to 2023, found that 30 per cent exceeded India's limit of 10 micrograms per gram. Every city sampled in Bihar showed evidence of adulteration, with a maximum of 6,416 micrograms per gram, while West Bengal was the one state where no city exceeded the limit. The odds of exceeding the limit were more than four times higher for loose powder and double-polished roots than for single-polished roots. The authors note that lead harms children's intellectual development and raises cardiovascular risk in adults, and that no level of exposure is known to be safe.
Buying haldi with less risk
Prefer whole or packed over loose powder
The Dietary Guidelines for Indians advise that powdered spices are more likely to be adulterated and that certified products should be bought. The eastern India survey found loose powder among the forms most often over the lead limit.
Be suspicious of an unusually bright, uniform yellow
The survey reports that the pigment is added mainly to enhance the colour of the root. Deep, even colour is what the adulteration is designed to produce, so it is not a sign of quality.
Know what the standard promises
FSSAI requires haldi to test negative for lead chromate and to hold no more than 10 parts per million of lead. A licensed, labelled pack is at least answerable to that standard.
Do not treat a supplement as the safer route
A capsule avoids the spice market but brings the concentration and absorption questions described above. The two risks are separate.
A worked example: haldi in the dal against a trial capsule
This is an illustration with invented details, not a real person. Take a 58-year-old retired schoolteacher in Kolkata with knee pain from osteoarthritis. She cooks with haldi every day, takes a tablet for blood pressure, and has been sent a message recommending 500 mg curcumin capsules with piperine, two a day. For the arithmetic, suppose her own share of the household's turmeric comes to 3 g a day, the top of the range FSSAI lists for the powder.
| Question | Working | Answer |
|---|---|---|
| Curcumin in her 3 g of haldi, at the survey average | 3,000 mg x 3.14 per cent | About 94 mg |
| The same, if the powder only just meets the standard | 3,000 mg x 2 per cent | 60 mg of curcuminoids |
| Haldi needed to match the trial amount of about 1,000 mg | 1,000 mg divided by 3.14 per cent | About 32 g, roughly ten times her intake |
| Curcumin from the two capsules | 2 x 500 mg | 1,000 mg, the amount the trials tested |
| Piperine, if each capsule holds 5 mg | 2 x 5 mg | 10 mg, inside FSSAI's 15 mg ceiling, which also carries a 30-day limit |
The numbers show that cooking cannot reproduce the trial, and that the capsules would. They do not show that she should take them. She is on a regular medicine, the product is a pepper-boosted one of the kind that features in the liver reports, and the pooled trials are short. Each of those points sends the decision to her doctor. Whatever is decided, the haldi stays in the dal.
What must a curcumin supplement label show?
A curcumin extract sold as a nutraceutical must carry the word NUTRACEUTICAL, the common name of the ingredient and the amount present, with an advisory on recommended usage and the warning NOT FOR MEDICINAL USE written prominently. FSSAI's regulations also require any known side effects, contraindications and product-drug interactions to be stated. Implied claims of curing a disease, or of drug-like efficacy, are prohibited. A pack that promises to end joint pain or protect the liver is outside those rules.
Common mistakes and myths about turmeric and curcumin
The commonest mistake is to quote extract trials as proof for the spice, or the spice's long history as proof that extracts are safe. Others follow from it: taking several turmeric products at once, choosing the highest-absorption formula on the assumption that more in the blood must be better, and continuing for years when the trials lasted weeks. The site's piece on joint pain in winter deals with what food can reasonably be expected to do.
NNWA courses that cover spices and supplements
Curcumin is examined as a case study in NNWA's Dietary Supplements and Nutraceuticals course, and food standards and adulteration are part of the Diploma in Nutrition. NNWA, a private skill academy in Kolkata, teaches online in English and Hindi; its courses train people to coach healthy clients and to refer medical cases, and none of them is a degree or a dietitian qualification.
Sources and further reading
Food Safety and Standards Authority of India. Food Safety and Standards (Food Products Standards and Food Additives) Regulations, 2011, compendium version XII. Regulation 2.9.18 sets the standard for turmeric whole and powder, including the curcuminoid minimum and the lead chromate test.
Food Safety and Standards Authority of India. Food Safety and Standards (Contaminants, Toxins and Residues) Regulations, 2011, compendium. Sets the limit for lead in turmeric, whole and powder, at 10 parts per million.
Food Safety and Standards Authority of India. Food Safety and Standards (Health Supplements, Nutraceuticals, Food for Special Dietary Use, Food for Special Medical Purpose, Functional Food and Novel Food) Regulations, 2016, compendium version I. Lists Curcuma longa in Schedule IV, curcuminoids and piperine in Schedule VI, excludes plain spices from the definition and sets the label rules.
ICMR-National Institute of Nutrition. Dietary Guidelines for Indians, 2024. Lists turmeric among spices that can be part of a balanced diet and advises on adulterated powdered spices.
Nutrition and Cancer. Tayyem RF and others (2006). Curcumin content of turmeric and curry powders. Measures curcumin in 28 spice products and gives the average for pure turmeric powder (doi:10.1207/s15327914nc5502_2).
Planta Medica. Shoba G and others (1998). Influence of piperine on the pharmacokinetics of curcumin in animals and human volunteers. The Bangalore study of 2 g of curcumin with and without 20 mg of piperine (doi:10.1055/s-2006-957450).
Journal of Medicinal Food. Daily JW and others (2016). Efficacy of Turmeric Extracts and Curcumin for Alleviating the Symptoms of Joint Arthritis: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. Eight trials, the pooled pain results, the amount of curcumin used, the authors' caution and the disclosure statement (doi:10.1089/jmf.2016.3705).
Bioscience Reports. Zeng L and others (2021). The efficacy and safety of Curcuma longa extract and curcumin supplements on osteoarthritis: a systematic review and meta-analysis. Pools 15 trials with 1,621 participants and lists the preparations each trial used (doi:10.1042/BSR20210817).
American Journal of Medicine. [Halegoua-DeMarzio D and others (2023). Liver Injury Associated with Turmeric, A Growing Problem: Ten Cases from the Drug-Induced Liver Injury Network [DILIN]](https://pmc.ncbi.nlm.nih.gov/articles/PMC9892270/). Describes the ten cases, their outcomes, the product analysis, the gene association and the funding (doi:10.1016/j.amjmed.2022.09.026).
Science of the Total Environment. Forsyth JE and others (2024). Evidence of turmeric adulteration with lead chromate across South Asia. The survey of 356 samples from 23 cities, including the Patna finding (doi:10.1016/j.scitotenv.2024.175003).
npj Science of Food. Forsyth JE and others (2026). Systemic drivers of toxic food adulteration: lead chromate in turmeric across eastern India. The survey of 503 samples from 34 cities in five eastern states, by state and by form of turmeric (doi:10.1038/s41538-026-00867-8).
National Center for Complementary and Integrative Health, US National Institutes of Health. Turmeric: Usefulness and Safety. Summarises the evidence, the side effects, the liver warning for high-absorption products and the cautions in pregnancy and breastfeeding.