What an Analytical Testing Lab Finds When Screening Ashwagandha, Turmeric, and Elderberry for Adulteration

Three of the supplement industry’s hottest botanicals. Three of the most adulterated raw material categories we see coming through our receiving dock in Countryside, IL.

The correlation isn’t accidental. High consumer demand creates pricing pressure. Pricing pressure creates incentive to cut corners somewhere in the supply chain — and that “somewhere” is almost always the raw material. By the time a blended tablet reaches a retail shelf, there’s no practical way to recover from a contaminated or misidentified botanical ingredient.

Here’s what actually shows up when a qualified analytical testing lab runs a complete screening panel on these three materials.

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The Adulteration Problem Is Bigger Than Your COA Suggests

A supplier-issued certificate of analysis is not a test result. It’s a document. And in our experience processing raw material submissions from Midwest supplement brands, the gap between what a COA claims and what third-party testing confirms can be significant — and sometimes alarming.

The American Botanical Council’s Botanical Adulterants Prevention Program (BAPP) has documented known adulteration patterns for over 50 botanicals, with detailed laboratory guidance for each. Ashwagandha, turmeric, and elderberry all appear on that list. Under 21 CFR Part 111, dietary supplement manufacturers are legally required to establish the identity of every raw material they use. That requirement doesn’t get satisfied by filing away a supplier COA.

What it actually requires is independent analytical testing. Here’s what that looks like for three specific botanicals.

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Ashwagandha: When the Withanolide Numbers Don’t Hold Up

Withania somnifera has been the supplement industry’s growth story for the past several years, and the raw material supply chain has struggled to keep pace with demand. That mismatch has consequences.

The primary adulteration pattern we see with ashwagandha root powder is dilution — blending genuine Withania somnifera with starchy root materials, lower-cost Withania species, or inert fillers. The adulterant materials are often visually indistinguishable from authentic ashwagandha. A macro examination tells you nothing useful.

The biomarker we look for is withanolide content, the class of steroidal lactones that defines ashwagandha’s bioactivity. Authentic KSM-66 or Sensoril-grade ashwagandha root extract is standardized to 2.5–5% total withanolides. Generic raw material from unqualified suppliers frequently tests below 1% — without any disclosure on the label. That’s not a potency variation. That’s a different product.

HPLC-UV remains the standard quantitative method for withanolide assay. We run this alongside a USP <203> HPTLC fingerprint analysis, which generates a characteristic chromatographic pattern for Withania somnifera. If the fingerprint doesn’t match the reference standard, no HPLC number redeems the material.

For ashwagandha root specifically, DNA barcoding using the ITS2 gene region has become a valuable confirmatory step — particularly when HPTLC results are ambiguous due to heavy processing or extraction. The reference sequences for Withania somnifera are well-characterized in the NCBI database, and a clean match rules out most substitution scenarios.

One thing worth noting for brands sourcing through Midwest distributors: many ashwagandha suppliers are aggregating material across multiple harvest lots and blending to hit a withanolide specification on paper. Batch-to-batch variability can be significant. Incoming testing on every lot — not just annual vendor audits — is the appropriate quality control.

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Turmeric: From Lead Chromate to Synthetic Curcumin, a Testing Minefield

Turmeric has one of the longest and most documented adulteration histories of any botanical in the supplement industry. The problems are layered, which makes a single-method screening approach genuinely inadequate.

The first problem is heavy metals. FDA Import Alert 28-14 specifically identifies turmeric as a commodity with elevated risk of lead contamination. The contamination mechanism is frequently lead chromate — a yellow pigment historically used in certain supply chains to enhance the visual appeal of ground product. USP <232>/<233> sets the oral exposure limit for lead at 10 µg per day in dietary supplements. A turmeric raw material running at 5–10 ppm lead can push a finished supplement dose over that limit with little margin. And unless you’re testing it, you won’t know.

ICP-MS is the only method that provides the sensitivity and specificity needed to quantify lead, arsenic, cadmium, and mercury at these concentrations in a botanical matrix. ICP-OES works well for higher-concentration applications, but for trace elemental analysis where lead at 2 ppm matters, ICP-MS is the right tool. Our standard botanical submissions go through a 21-element ICP-MS panel as part of routine heavy metals screening.

The second problem is curcuminoid authenticity. Curcumin — the primary active curcuminoid in turmeric — is now commercially synthesized, and synthetic curcumin costs significantly less than curcumin extracted from Curcuma longa rhizome. Blending synthetic curcumin into a turmeric extract inflates the measured curcuminoid percentage without any botanical authenticity. AOAC method 2012.19 is the standard quantitative assay for curcuminoids, but it cannot distinguish synthetic from natural origin on its own.

That distinction requires stable isotope ratio analysis (δ¹³C measurement via IRMS), which exploits the different carbon isotope signature between plant-derived and petroleum-derived curcumin. It’s not a routine test. But if you’re sourcing turmeric extract at commodity pricing from a supplier you haven’t deeply qualified, it’s worth requesting before you run a large production batch.

The third issue is species substitution: Curcuma aromatica or Curcuma zedoaria in place of Curcuma longa. HPTLC fingerprinting catches this reliably. The chromatographic profiles of these species are distinct enough that a well-run HPTLC plate makes the call clearly — no ambiguity.

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Elderberry: DNA Barcoding Is No Longer Optional

Sambucus nigra — European black elderberry — is the species with the documented clinical evidence for immune support applications. It’s also the species that commands the highest price. And it’s increasingly being substituted with, or diluted by, Sambucus canadensis (American elder), other Sambucus species, or entirely different berry materials processed to match the appearance.

Morphological examination of elderberry powder or extract is essentially useless for species confirmation. The processing destroys most structural evidence. Anthocyanin pigment profiles can be partially informative — Sambucus nigra produces a characteristic profile dominated by cyanidin-3-sambubioside and cyanidin-3-glucoside — but other dark berry sources can produce overlapping pigment patterns that fool a chromatographic assay without additional orthogonal confirmation.

DNA barcoding using the ITS2 gene region provides definitive species-level identification. We’ve processed submissions where the anthocyanin numbers looked plausible on their face, but the DNA result came back inconsistent with Sambucus nigra, indicating blending with other berry materials. Without that DNA step, the adulteration would have passed undetected.

Elderberry also carries microbiological risk that’s underappreciated in most conversations about this category. Raw elderberry material — fruit powders, freeze-dried concentrates — can arrive with elevated aerobic plate counts or objectionable organisms if drying and storage conditions were inadequate. USP <61>/<62> limits for botanical powders intended for oral use generally require total aerobic microbial count below 10⁴ CFU/g and absence of Salmonella spp. and E. coli. Running a microbial panel alongside identity and potency testing isn’t a premium add-on for elderberry. It’s basic incoming quality discipline.

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What a Complete Screening Protocol Actually Looks Like

For any of these three botanicals arriving as a raw material for a finished dietary supplement, a defensible incoming quality program includes the following:

Identity confirmation: HPTLC fingerprint per USP <203>, run against an authenticated reference standard. For elderberry, add ITS2 DNA barcoding. For ashwagandha, add DNA barcoding as a confirmatory second tier.

Potency and marker assay: HPLC for withanolides (ashwagandha); curcuminoids by AOAC 2012.19 (turmeric); anthocyanins by the pH differential method (elderberry). Compare every result against the supplier’s COA claim — the delta tells you a lot.

Heavy metals: 21-element ICP-MS panel per USP <232>/<233>. Evaluate against USP oral exposure limits for the intended dose. Flag any turmeric material above 2 ppm lead for isotope ratio investigation before release.

Microbiology: USP <61>/<62> panel covering total aerobic count, total yeast and mold, Salmonella, and E. coli. Required for all botanical raw materials without exception.

Pesticides and mycotoxins: Not always included in base panels, but worth adding for any botanical arriving from a supply chain with ambiguous agricultural practices. AOAC methods apply for multi-residue pesticide screening; LC-MS/MS for aflatoxins B1, B2, G1, and G2.

Brands receiving raw material at a Midwest distribution point don’t always have the in-house capacity to run this kind of protocol. That’s a solvable logistics problem. Our receiving facility in Countryside, IL accepts raw material samples directly, with testing performed at our ISO 17025-accredited California labs and CoA turnaround in 5–7 business days. The geography shouldn’t be a barrier to testing discipline.

The supply chain for these three botanicals isn’t going to get cleaner without testing pressure from buyers. Every brand that skips incoming verification because a supplier COA looks acceptable is, functionally, subsidizing the next adulteration. That’s a vote worth reconsidering before your next production run.

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Written by Nour Abochama, VP Operations, Qalitex | Quality Consultant, Ayah Labs. Learn more about our team

Ship your sample to our Chicago facility — get a Qalitex CoA in 5–7 days. Contact us

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• ISO 17025 accreditation and supplement testing services — Full-service analytical lab for botanicals, dietary supplements, and raw materials, operating under ISO 17025 accreditation from our California facilities.