Overview
This crowd-funded observational study analyzed 34 whey protein supplements sold in India, comparing 18 medical-pharmaceutical products (prescribed by physicians) with 16 nutraceutical products (marketed for fitness). Heavy metals (arsenic, cadmium, lead, mercury, copper) were measured by ICP-MS at an FSSAI-approved laboratory alongside protein content, amino acid profiles, sugars, aflatoxins, hormones, and pesticides.
Mercury was absent in all 34 products. Lead was detected only in pharmaceutical products. Cadmium and arsenic were the most common heavy-metal contaminants overall. The pharmaceutical category showed a significantly higher overall contamination rate (38%) than the nutraceutical category (25%, P < 0.05). Arsenic contamination was 3.5-fold higher in pharmaceutical products (from Fig. 3 caption).
Key numbers
Heavy metal findings (Section 3.3 and Fig. 3):
- Mercury total mercury (tHg): not detected in any of the 34 products.
- Lead (Pb): detected only in pharmaceutical products; zero detection in nutraceutical powders.
- Cadmium (Cd): detected in both categories; most prevalent contaminant class.
- Total arsenic (tAs): detected in both categories; 3.5-fold higher detection rate in pharmaceutical vs nutraceutical.
- Copper (Cu): nutraceuticals 0.531-4.4 mg/kg (mean 1.68 mg/kg; 75% of products, 12/16); pharmaceuticals 0.529-33.056 mg/kg (78% of products, 14/18); 3 pharmaceutical products contained 10 mg/kg or more.
- Overall contamination rate (any metal above LOQ): pharmaceutical 38%, nutraceutical 25% (P < 0.05).
Specific cadmium and arsenic per-product concentrations are presented in Figure 3 (bar chart showing percentage detection by product category); numeric concentration values for Cd, arsenic (As) and Pb are not tabulated separately in the paper text.
No LOQ values for the toxic metals are stated in the paper text.
Methods (brief)
ICP-MS for arsenic, cadmium, lead, mercury and copper per Bureau of Indian Standards and AOAC standards; analyzed at an FSSAI-approved laboratory. Full method documentation in supplementary materials. Products were purchased from manufacturer or authorized dealers, authenticated, and transported to the laboratory under chain of custody.
Evidence fitness
All 34 products are whey-based; casein powder and plant proteins are not included. The nutraceutical category closely corresponds to internationally sourced whey concentrates, isolates and hydrolysates. The pharmaceutical category represents lower-protein, often domestically formulated products with higher rates of mislabeling and contamination. The absence of numeric per-product concentrations for Pb, Cd and As limits use in occurrence synthesis; the paper is most useful for comparative contamination patterns (nutraceutical vs pharmaceutical whey, Indian market) and for the absence of mercury finding.
Related evidence
- Whey
- Casein
- Non-soy protein sources
- Ingredient class — protein/collagen powders
- Lead
- Cadmium
- Arsenic
- Mercury
Update history
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