Published in Pharmaceutical Biology, the paper analyzed 48 scientific publications on turmeric adulteration and presented laboratory identity and authenticity assessments of commercial turmeric products available from six continents.
Mark Blumenthal, founder and executive director of the American Botanical Council (ABC) and co-author on the paper, called the review a significant milestone for the responsible sector of the herb and medicinal plant community.
“Since turmeric is consistently documented as one of the top-selling herbal dietary supplements in the United States, it is fitting that it should be the subject of BAPP’s 100th peer-reviewed publication,” he said. “It should be noted that there are many authentic and reliable turmeric products that are produced and sold by responsible companies.”
Founded in 2011 to educate the industry about adulteration, the ABC-AHP-NCNPR BAPP published a review of popular herbs published in 2024, identifying a 16.5% adulteration rate in 1,247 commercial turmeric samples. The latest review includes 33 additional publications and 988 more samples.
Rates and forms of turmeric adulteration
In total, 448 out of 2,235 turmeric ingredients and products were found to be adulterated, corresponding to an estimated adulteration rate of 20%. After excluding products that could not be assigned to either category, the adulteration rate was slightly higher in turmeric dietary supplements (22.0%) than in turmeric sold as spice (20.4%). Further, when the assessment was restricted to papers with validated test methods, the adulteration rate for food and dietary supplements increased to 27.1% (62 of 229 samples).
Forms of adulteration included artificial dyes, undeclared diluents such as cornstarch and synthetic curcumin, among other lower-cost substances. The report identified synthetic curcumin—often mislabeled as turmeric extract—as the most common type of adulteration in dietary and food supplements, with the highest prevalence observed in Europe and North America.
Stefan Gafner, PhD, chief science officer of ABC and co-author on the paper, said review the process revealed many challenges involved in determining the true extent of adulteration.
“The information differs from one geographical area to the other and depends on where you buy the turmeric and what form you buy,” he explained. “Other factors that impact the results are the type of adulterants that were included in the investigation, the analytical method used and even who carried out the research.”
Identification of lead chromate as color enhancer was reported mainly from Southern Asia, while dilution with starches and adulteration with other dyes is a global concern. Substitution of Curcuma longa with other species was predominant in China, the Middle East and Southern Asia.
Standards also vary from region to region. The U.S. Pharmacopeia requires a minimum content of 3% total curcuminoids and 3% essential oil; the European Pharmacopeia specifies minimum levels of 2% total curcuminoids and 2.5% essential oil; and the Chinese Pharmacopeia requires at least 7% volatile oil and 1% curcumin, without specifying a minimum for total curcuminoids.
While the data showed adulteration is a clear problem, Dr. Gafner noted that the review highlighted evidence from Bangladesh that a combination of education, inspections and regulatory enforcement “can have a profound impact.”
After being alerted to widespread lead chromate adulteration, the Bangladesh Food Safety Authority (BFSA) made turmeric adulteration a prosecutable act, issued warnings informing of the danger to health, imposed fines, and trained employees of the BFSA to use handheld analyzers to detect lead and chromium in turmeric samples. As a result, the number of lead-contaminated turmeric samples decreased from 47% in 2019, to 5% in the beginning of 2020, 2.3% in the fall of 2020, and 0% in the beginning of 2021. (Forsyth et al. 2023)
“This gives me hope that the educational efforts of the ABC-AHP-NCNPR Botanical Adulterants Prevention Program are bearing fruit and that with the help of industry and regulators, we can improve the authenticity of botanical ingredients offered on the market,” Dr. Gafner said.
Commenting on the significance of the review findings, Petra Erlandson, vice president of sales at contract botanical and fungi testing lab Alkemist Labs, said that the company watches BAPP program updates as well as other publications like this to monitor adulteration trends and strengthen its own test methods.
“I applaud the authors and the ABC-AHP-NCNPR BAPP program for this paper and shining a light on turmeric adulteration,” she added. “It is critically important for the industry to stay up to date and ever vigilant on botanical adulteration issues. Adulteration is a moving target! Regarding turmeric specifically, we have already updated our methods to include more reference materials of potentially adulterating as named in the article.”
A growing market with deep roots
Turmeric, long revered in Ayurveda and Traditional Chinese Medicine, has established itself as a mainstream wellness ingredient across nutraceuticals, functional foods and dietary supplements.
The botanical has been the subject of rigorous study, with particular focus on its anti-inflammatory effects and its benefits for joint health, gut health, post-exercise recovery, blood pressure control and weight management.
According to ABC’s 2024 Herb Market Report, turmeric dietary supplements ranked first in retail sales in the U.S. natural expanded channel and fourth in the U.S. mainstream channel, with combined 2024 sales of more than $179 million. Strategic Market Research forecasts that the global turmeric supplement market will expand at a compound annual growth rate (CAGR) of 6.8%, rising from $1.9 billion in 2024 to $2.9 billion by 2030.
India stands as the world’s largest producer of turmeric, supplying approximately 80% of the global market. During the 2023–2024 season, India’s turmeric exports India were valued at around US$226.5 million, based on a report of the Government of India cited in the BAPP review.
In 2023, the United States was the largest importer of turmeric, followed by India, Germany, Malaysia, Morocco and China, according to insights from global agri-food business data provider Tridge.
With global demand for curcumin on the rise, turmeric cultivation has expanded into neighboring countries (China, Myanmar, Nigeria, and Bangladesh) to meet market needs. While increased cultivation helps improve availability, heightened demand has also introduced quality challenges within the industry.
Commenting on this challenge, KG Rao, CEO of DolCas Biotech, said that economic pressure has led to the adulteration of curcumin extracts through the addition of synthetically manufactured curcumin, which is chemically produced from petrochemical or fossil-fuel-derived intermediates. The company produces the branded Curcugen whole turmeric extract. standardized to all three major curcuminoids.
“Synthetic curcumin can be produced at scale, independent of agricultural cycles and is often used to artificially increase curcumin assay values at a significantly lower cost,” Rao noted. “From a purely chemical standpoint, the curcumin molecule produced synthetically may appear identical to naturally derived curcumin. However, natural turmeric extracts contain a broader matrix of bioactive constituents that are absent in synthetic material.”
The primary bioactive constituents include curcumin, demethoxycurcumin (DMC), bisdemethoxycurcumin (BDMC), naturally occurring turmeric essential oils, fixed oils and select polyphenols and polysaccharides.
“This complex natural composition is characteristic of whole-plant turmeric extracts and reflects how curcumin has traditionally been consumed as part of the food supply,” Rao said, adding that there is limited publicly available data on the long-term daily consumption of synthetically manufactured curcumin. “For this reason, transparency in sourcing, manufacturing practices and labeling is increasingly important for brands and consumers alike when evaluating curcumin-containing products.”
Copycats ‘conducting uncontrolled experiments on consumers’
Shaheen Majeed, global CEO and managing director of ingredient supplier Sabinsa, said the market has become flooded with cheap so-called ‘curcumin’.
“Curcumin adulteration is a serious and growing threat to both consumer safety and industry credibility,” he said. “When clinical research drove mainstream adoption of standardized turmeric extracts like our Curcumin C3 Complex, we immediately saw the market flooded with impossibly cheap ‘curcumin’.”
His company’s own testing revealed some materials contained “over 40% synthetic compounds designed to pass routine analytical testing while masquerading as natural curcuminoids.”
“What makes modern adulteration particularly insidious is its sophistication,” Majeed noted. “Synthetic substitutes require advanced techniques like carbon isotope ratio analysis to detect, which are methods not included in standard quality programs. This allows compromised materials to move through supply chains undetected, carrying certificates of analysis that provide a false sense of security.”
He emphasized that the industry must recognize that knowing what to test for is just as important as knowing how to test. At Sabinsa, this is addressed through comprehensive chain-of-custody documentation that tracks every batch from cultivation to the final product, including harvest timing, processing parameters and traceability at each transfer point. Industry experience shows that gaps in documentation—common in aggregated commodity supply chains—are often where adulteration occurs. The firm’s vertical integration further reduces risk by limiting external touchpoints, while routine facility audits reinforce transparency.
Beyond standard identity and potency testing, Sabinsa also employs layered analytical strategies including carbon isotope analysis for synthetic detection, DNA-based botanical verification and comprehensive contaminant screening.
Majeed highlighted that the commodification of research-backed botanicals represents one of the industry’s most dangerous trends.
“Clinical studies on specific, standardized materials don’t transfer to generic alternatives from multiple sources using different processing methods,” he said.
“When brands source ‘equivalent’ versions to save costs, they’re essentially conducting uncontrolled experiments on consumers. The industry’s future depends on elevating quality over cost and research integrity over generic equivalence, because one adulterated ingredient can destroy years of brand building and consumer trust.”
Industry initiatives
Stephanie Calafat, global product manager of physical health & weight management at Givaudan Taste & Wellbeing, highlighted the firm’s Sourcing4Good program, which encompasses Turmitrace, a targeted initiative ensuring the quality and sustainability of turmeric root.
“Turmitrace provides end-to-end digital transparency from the field to the finished raw material, controls for select varieties of roots that are rich in curcumin and verified to be contaminant-free,” she said.
“Led by our agronomy team in India, it combines crop science with farmer and stakeholder training and incentive programs that foster sustainable and regenerative practices. This initiative extends to manufacturing, maintaining transparency during processing and robust quality assurance to confirm authenticity and test for contaminants including illegal dyes and harsh extraction solvents,” she explained, adding that the firm also invites customers to witness the process firsthand.
Lubrizol, the supplier of iCurcushine microcapsules, said the firm relies on a fully traceable and rigorously certified raw‑material supply to ensure the curcumin used is authenticated for purity, quality and non‑adulteration.
“We pair this with strict quality controls and documentation across every production step,” said Isabel Gómez, global marketing manager at Lubrizol, adding that the microencapsulation technology itself further safeguards ingredient integrity.
Kratika Gupta, vice president of global marketing at OmniActive Health Technologies, noted that adulteration remains a real, global challenge but that the best defense is to build “trust by design” into the ingredient supply chain through supplier qualification, identity verification and robust traceability, as well as third-party programs for an added “layer of transparency and confidence for customers.”
Source: Pharm Biol. 2026;64(1):87-107. doi: 10.1080/13880209.2025.2606229. ”A scoping review of turmeric adulteration based on data from six continents”. Authors: Stefan Gafner et al.
