What Is a Mycotoxin Urine Test and What Do Your Results Mean?

A mycotoxin urine test measures toxic mold byproducts your body is actively excreting. If your doctor found mycotoxins in your urine, this guide explains what the levels mean and what to do about your home.

What Is a Mycotoxin Urine Test?

A mycotoxin urine test analyzes a urine sample for the presence and concentration of chemical compounds produced by certain mold species as byproducts of their metabolism. Not all molds produce them, but the ones commonly found in water-damaged buildings often do — Stachybotrys, Aspergillus, Penicillium, Chaetomium, and Fusarium are among the species capable of producing mycotoxins under the right conditions.

The toxins themselves are not spores. They are much smaller, can be carried on dust particles, and can be inhaled or ingested without you knowing. Once inside the body, some are processed and excreted through urine. That is what the test picks up.

Depending on which panel your doctor orders, it may screen for anywhere from 11 to 31 different toxins. The most accurate tests use liquid chromatography mass spectrometry (LC-MS/MS), which can detect toxins down to one part per billion. Some labs use ELISA, which measures immune antibodies rather than the toxins directly. LC-MS/MS is generally considered more reliable.

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What a Positive Result Means

If one or more toxins come back elevated, it means your body is excreting measurable amounts of that compound. It does not, on its own, confirm that the source is your home. This is an important distinction.
Mycotoxins are found in food as well as in buildings. Ochratoxin A appears in coffee, dried fruits, wine, and some grains. Aflatoxins are common in peanuts and corn. A 2025 study found deoxynivalenol in the urine of nearly all participants tested, attributed to diet. So a positive result requires context before drawing conclusions about your home.
That said, certain toxins are more closely associated with indoor mold than with food. The toxin type matters as much as the level. Your doctor should be interpreting which toxins are elevated and whether they make sense given your symptoms, diet, and living situation.
Here is what mycotoxin urine test results typically look like:

What Each Toxin Is Telling You

Most panels test for the same core set of mycotoxins. The ones below are the most widely used in various mycotoxin tests:
Food or environment signal
Ochratoxin A (OTA)
Most common elevated toxin on these panels
Produced by

Aspergillus, Penicillium

What it means if elevated

This can be elevated if you are inhaling or ingesting a lot of mold because aspergillus is common on food at and home. Be sure to check your coffee, wine, grain consumption as well as your house if this is elevated

Environment signal
Trichothecenes (ROE, VRA)
Roridin E, Verrucarin A
Produced by

Stachybotrys, Fusarium, Myrothecium

What it means if elevated

Not a significant dietary toxin. Elevated levels strongly suggest a water-damaged building source. Found on board, wood and wallpaper.

Environment signal
Gliotoxin (GTX)
Produced by

Aspergillus fumigatus, Penicillium, Trichoderma

What it means if elevated

Not a dietary toxin at meaningful levels. Presence points to airborne or environmental exposure. Associated with immune suppression.

Primarily food Signal
Aflatoxin M1 (AFM1)
Produced by

Aspergillus flavus, A. parasiticus

What it means if elevated

Main source is peanuts, corn, dairy products. An elevated result is less likely to point to a home mold problem than trichothecenes or gliotoxin.

Food or environment signal
Sterigmatocystin (STC)
Produced by

Aspergillus versicolor, Chaetomium, Stachybotrys

What it means if elevated

Found on wallpaper and carpeting in water-damaged buildings. Group 2B carcinogen. Precursor to aflatoxin B1.

Food or environment signal
Zearalenone (ZEA)
Produced by

Fusarium graminearum, F. culmorum

What it means if elevated

Found in cereal crops and water-damaged buildings. Has endocrine-disrupting properties. Context and other toxin results matter.

What This Test Does and Does Not Tell You

What it tells you

Which mycotoxins your body is currently excreting and at what concentration.

Whether levels are above the lab's reference range for a healthy population.

Which toxin classes are present, which can suggest whether a building or food is the more likely source.

A baseline for tracking whether levels change over time or after moving or remediation.

What it does not tell you

Whether the exposure is coming from your home specifically. Environmental testing is needed to confirm the source.

Whether levels are clinically significant. There are no universally agreed reference ranges across labs.

Which mold species in your home is producing the toxins. That requires a surface or air test.

That your home is the problem. A positive result is a reason to investigate, not an automatic remediation order.

A positive mycotoxin urine test, particularly for trichothecenes or gliotoxin, is a reason to look at your home seriously and schedule a mold inspection and testing. The body test tells you something got in. Environmental testing tells you where it came from.
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