Everything you need to know
Mycotoxins are toxic secondary metabolites produced by filamentous fungi (molds) that commonly contaminate grain crops, botanical ingredients, and nutraceutical raw materials. They are heat-stable, meaning cooking or processing does not eliminate them. Understanding which mycotoxins matter, where they come from, and how to test for them is essential for supplement quality programs.
What are mycotoxins and why do they form?
Mycotoxins are naturally occurring toxic compounds produced by molds — primarily Aspergillus, Fusarium, and Penicillium species. They form when molds colonize crops or stored commodities under warm, humid conditions. A single mold species can produce multiple mycotoxins, and multiple mold species can co-occur on the same raw material. The most toxicologically significant mycotoxins for dietary supplements are aflatoxins, ochratoxin A (OTA), fumonisins, zearalenone (ZEA), and trichothecenes (DON, T-2, HT-2).
Which mycotoxins are most regulated in food and supplements?
Aflatoxins (B1, B2, G1, G2): Most widely regulated globally. FDA action level 20 ppb in food; EU limit 4 ppb total, 2 ppb B1. Linked to hepatocellular carcinoma. Ochratoxin A (OTA): EU limits 5 ppb in roasted coffee, 10 ppb in cereals. Nephrotoxic and a possible carcinogen. Common in coffee, wine, dried fruits, and herbal products. Fumonisins (B1, B2): FDA guidance 2–4 ppm in corn products; EU limits under Regulation 1881/2006. Associated with esophageal cancer risk. Zearalenone (ZEA): Estrogenic mycotoxin; EU limits 100–400 ppb in cereals. Deoxynivalenol (DON): Immune-modulating; FDA guidance 1 ppm in human food, EU 750 ppb in cereal products.
Which supplement ingredients carry the highest mycotoxin risk?
The highest-risk supplement ingredients by category: Grain-based: oat flour, corn starch, rice bran, barley grass (risk: DON, fumonisins, aflatoxins); Botanical/herbal: chili pepper, paprika, turmeric, black pepper, licorice (risk: aflatoxins, OTA); Tree nuts and peanuts: peanut powder, almond flour, walnut extracts (risk: aflatoxins); Dried fruits: raisins, figs, apricots, dates (risk: OTA); Mushrooms: reishi, lion's mane, chaga, cordyceps extracts (risk: aflatoxins, OTA); Coffee: green coffee, coffee extract, mushroom coffee blends (risk: OTA, aflatoxins).
What analytical method is used to test for mycotoxins?
LC-MS/MS (liquid chromatography-tandem mass spectrometry) is the gold standard for mycotoxin testing. It provides simultaneous quantification of multiple mycotoxins in a single injection with high sensitivity (sub-ppb detection limits), confirmed identification via mass fragmentation, and validated recovery data. Older methods like ELISA and immunoaffinity columns are faster and cheaper but prone to cross-reactivity and false positives. For regulatory compliance COAs, LC-MS/MS is the expected method.
What is the regulatory status of mycotoxins in US dietary supplements?
FDA does not have specific action levels for mycotoxins in finished dietary supplements the way it does for corn (fumonisins) or peanuts (aflatoxins). However, FDA applies its general adulteration provisions under the FD&C Act — a dietary supplement contaminated with harmful levels of mycotoxins would be considered adulterated. The EU, by contrast, has specific limits for mycotoxins in herb teas and food supplements under Regulation (EC) No 1881/2006. Brands exporting to the EU need to comply with EU limits regardless of US market requirements.
How do I know if my raw material needs mycotoxin testing?
Mycotoxin testing is highly recommended if any of these apply: your formulation contains grain-based, nut-based, or botanical ingredients; your supplier is sourcing from Asia, Africa, or South America (higher risk regions); your ingredient has a history of mycotoxin issues in industry surveillance; you are selling to EU, Japan, or Australia (stricter limits); or you are marketing to vulnerable populations (children, immunocompromised individuals). Get a full mycotoxin panel for your supplement.