The True Content and Faces Behind America's Best-Selling Collagen: 2020 Collagen Heavy Metals Study

Summary

This is a Clean Label Project and Organic Consumers Association white paper reporting a market survey of heavy-metal contamination in 30 collagen supplement products purchased from US online and brick-and-mortar retailers. Samples were drawn from Amazon best-seller listings and the cohort tested in Clean Label Project’s earlier 2018 protein-powder investigation, then sent to two ISO-accredited analytical chemistry laboratories for total arsenic, cadmium, total mercury, and lead by ICP-MS (EPA Methods 6020A and 3015, level of quantification 8 ppb). Results were reported on a per-serving basis (µg/serving) and benchmarked against the California Office of Environmental Health Hazard Assessment Proposition 65 Safe Harbor levels rather than against concentration limits. The headline pattern is that arsenic was the most prevalent contaminant (64% of products with measurable per-serving arsenic (As), range 0.09 to 4.7 µg/serving), lead was measurable in 37% of products (range 0.09 to 1.57 µg/serving, with the highest single-serving exposure ~3× the Prop 65 lead (Pb) MADL), and cadmium was less prevalent (17% measurable) but reached 9.17 µg/serving in the highest-loading product, ~2× the Prop 65 oral cadmium (Cd) MADL on a single-serving basis. Mercury was non-detect or below the 8 ppb LOQ in all 30 products. The report is non-peer-reviewed and structured as a consumer-advocacy document, but the underlying analytical chemistry is laboratory-grade and the per-serving exposure framing is a useful occurrence dataset for the collagen-supplement product category.

Key numbers

Source reports per-serving heavy-metal mass in µg/serving for arsenic, cadmium, and lead (Chart 1, page 10). Mercury is reported qualitatively as ND or “Trace” (Trace = detected but below the 8 ppb LOQ); no quantitative mercury (Hg) values are given. Population summaries are author-reported in the Findings section (pages 3-5). Detection rate denominators are n=30 unless noted.

Worst-case per-serving findings (Chart 1):

• Total arsenic top loader: an unflavored bovine collagen-peptide product at 4.7 µg total arsenic (tAs)/serving (20 g serving), below the 10 µg/d Prop 65 NSRL for As.
• Cadmium top loader: a chocolate collagen-protein product at 9.17 µg Cd/serving (41 g serving). The report compares this to a 4.1 µg/day Prop 65 Cd reference and notes it is “over 2 times” that benchmark.
• Lead top loader: an unflavored bovine collagen-peptide product at 1.57 µg Pb/serving (20 g serving), “over 3 times the State of California threshold” (Prop 65 Pb MADL = 0.5 µg/day).
• Lead secondary cluster: three additional chocolate flavored / keto-style collagen products each exceeded 2× the Prop 65 Pb MADL on a per-serving basis (1.10 to 1.33 µg Pb/serving).
• Mercury: the LOQ-limited “Trace” classification covered 34% of products; no individual µg/serving values are reported because all detections fell below the 8 ppb LOQ.

Context for the comparison ladders. The source white paper itself prints the numeric tAs comparison value on the face of the PDF (“None of the products tested exceeded the 10 micrograms/serving State of California threshold,” page 4), but for cadmium and lead it expresses the worst-case findings as multiples of the Prop 65 threshold (“over 2 times” Cd; “over 3 times” Pb) without naming the underlying µg/day reference values. The standard California OEHHA Proposition 65 Safe Harbor levels that those multipliers back-derive against are: tAs 10 µg/day NSRL (cancer endpoint); Cd 4.1 µg/day MADL (oral reproductive endpoint); Pb 0.5 µg/day MADL (oral reproductive endpoint). Those Cd and Pb numerics are imported here from OEHHA’s published Safe Harbor list, not from the white paper’s own text. The report does not cite a Prop 65 reference for total mercury and does not interpret the trace Hg results against any threshold.

Methods (brief)

Thirty collagen supplement products were procured from US local, national, and online retailers using Clean Label Project’s documented Consumer Chain of Custody and Sampling Methodology, intended to replicate the consumer purchasing experience. Samples were sent to two ISO-accredited analytical chemistry laboratories — HRI Labs and Ellipse Analytics — for total arsenic, cadmium, total mercury, and lead analysis by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), using US EPA Method 6020A with EPA Method 3015 microwave-assisted acid digestion. The reported level of quantification was 8 parts per billion. Results were calculated on a per-serving basis (µg/serving) using each product’s label-declared serving size (2.6 g to 41 g across the cohort) and compared to California Office of Environmental Health Hazard Assessment (OEHHA) Proposition 65 Safe Harbor exposure levels. No metal speciation was performed; arsenic is reported as total As and mercury as total Hg. No replicate-sample protocol, per-lab assignment of products, or lab-blank/spike-recovery summary is disclosed in the public white paper.

Implications

• This is the Index’s per-serving occurrence dataset for the US collagen supplement market in 2019-2020, complementing the concentration-basis European marine-collagen data in Toxic metals and metalloids in collagen supplements of fish and jellyfish origin: Risk assessment for daily intake and the broader protein-powder occurrence base in A human health risk assessment of heavy metal ingestion among consumers of protein powder supplements. Together these support the Ingredient class — protein/collagen powders product page.
• The per-serving framing (µg/serving against Prop 65 daily reference levels) is the consumer-relevant axis for this product category, because serving size varies four-fold across products (2.6 g to 41 g) and concentration-only data understates per-use exposure for high-serving keto-style chocolate collagens.
• Lead is the most regulatorily salient finding: 37% of the surveyed market had measurable per-serving Pb, the worst single product was ~3× the Prop 65 Pb MADL on a single-serving basis, and three additional products each exceeded 2× that benchmark.
• Cadmium prevalence is lower (17%) but the high-end exposure (9.17 µg/serving) is the largest single-analyte exceedance in the cohort relative to its Prop 65 reference.
• Total mercury was not a meaningful exposure signal at the 8 ppb LOQ used; HMI ingredient/product pages should not draw a total mercury (tHg) signal from this source.
• Evidence fitness caveat: non-peer-reviewed industry/advocacy white paper, n=30 single-pull market sample, accredited-lab ICP-MS but no per-product replicate disclosure, no lab-blank or recovery reporting, no speciation. Treat as a B-tier per-serving occurrence anchor rather than as a definitive market-distribution estimate.

Related evidence

• Lead
• Cadmium
• Arsenic
• Mercury

Update history

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