What is Sterigmatocystin (STC)? And Why Does the Toxin Zoomer Test for It?

Mold-derived polyketide mycotoxin

Sterigmatocystin (STC) is a polyketide mycotoxin produced by certain mold species. Measuring STC in biological samples can indicate recent exposure to mold-related toxins and help contextualize that exposure alongside other toxicants and individual detox capacity.

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Sterigmatocystin (STC)

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About Sterigmatocystin (STC)

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About Sterigmatocystin (STC)

Overview and History

Sterigmatocystin is a secondary metabolite produced by some filamentous fungi, most often species in Aspergillus and related genera. Chemically it is a polyketide-derived mycotoxin structurally related to the aflatoxin family and has been identified in contaminated foodstuffs and in damp indoor environments. Historically, STC gained attention as a stable, measurable marker of mold activity and contamination. In ecological terms it is a microbial chemical that likely serves competitive or defensive roles for the producing organism; in laboratory research it has been studied for effects on cellular systems, which is why it appears in exposure-focused testing panels.

Interpreting Highs and Lows

Higher urinary or environmental levels of STC most commonly indicate recent contact with molds that produce this compound—this can arise from contaminated food or from water-damaged buildings and indoor molds. Elevated STC should be interpreted with other exposure markers, environmental history, and detox-genetic data to understand timing and likely sources. Low or undetectable STC generally suggests little or no recent exposure above the test’s detection limit, but does not rule out past exposure or exposure to other mold toxins; interpretation is always more informative within the full Toxin Zoomer profile.

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STC is included in the Toxin Zoomer to provide a specific, measurable indicator of mold-related toxicant exposure. As a urinary mycotoxin marker it helps clinicians map exposure patterns and combine that information with detoxification genetics and other toxicant measurements to guide individualized assessment of environmental burden and physiological capacity.

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Sterigmatocystin (STC) FAQs

What is Sterigmatocystin (STC) and why is it important?

STC is a chemical produced by some mold species that can contaminate crops and grow in damp indoor areas. It’s measured because its presence indicates recent contact with certain mold toxins. Knowing STC levels gives clinicians objective information about possible mold exposure to compare with symptoms and environmental history.

What does it mean if my Sterigmatocystin (STC) levels are low?

Low or undetectable STC usually suggests there has been little recent exposure to molds that produce this compound or that levels are below the test’s detection limit. It can also reflect variability in exposure timing, metabolism, or sample collection. Clinicians interpret low STC alongside other toxicant results and genetic data to form a complete exposure picture.

What does it mean if my Sterigmatocystin (STC) levels are high?

Higher STC levels suggest recent contact with molds that produce this mycotoxin, such as contamination in food or a water-damaged indoor environment. Elevated results point to an exposure pattern that warrants correlation with environmental history, other mycotoxin findings, and detoxification genetics. Clinical interpretation requires the full panel and provider assessment to clarify likely sources and relevance.

Why is Sterigmatocystin (STC) measured on the Toxin Zoomer?

Measuring STC gives a targeted signal of mold-derived toxicant exposure that complements metals, chemicals, PFAS, and detox-genetic data. Including STC helps providers link lab findings to likely environmental sources and personalize assessment of toxic burden and detox capacity.

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