How Urine Mycotoxin Testing Actually Works

If you’ve been dealing with symptoms that haven’t been fully explained, you may have come across mycotoxin testing and wondered whether it’s credible. It’s an emerging area, and it can be hard to tell what’s solid science and what isn’t, so it helps to understand exactly how a urine mycotoxin test works.

This guide explains each step in plain words. It also covers what your report means, and what a result can and can’t tell you.

Key takeaways

• A urine mycotoxin test looks for tiny traces of mould toxins in your urine.
• The lab does four main jobs. It frees toxins your body has “tagged”, cleans the sample, finds and measures each toxin, then adjusts for how watery your urine is.
• Modern tests can measure amounts as small as a few billionths of a gram in a litre of urine [7].
• Your result shows recent exposure from all sources, including food. It can’t diagnose illness or tell you where mould is growing [12].
• Labs use different methods and cut-offs, so results from two labs can’t be compared directly.
• Good preparation and a practitioner review turn a number into a useful next step.

So, how does a urine mycotoxin test actually work?

The testing is done in a lab, using a small urine sample you collect at home. Here’s how it works: the lab frees the mould toxins your body has tagged for removal, a very sensitive machine then finds and measures each one, and the results are adjusted for how watery your urine was. Our advanced Mycotoxin Urine Test is launching soon, get on the list and be first to know when it does.

What is a mycotoxin, and how does it get into urine?

Mycotoxins are harmful substances made by some moulds, most come from food but some come from your environment. Your liver changes them so they’re easier to get rid of and your kidneys pass many of them out in your urine. That’s why urine is a handy sample to test.

Common mycotoxins include ochratoxin A, aflatoxins, zearalenone, citrinin and deoxynivalenol. For most people, food is the main source; cereals, nuts, spices, dried fruit and coffee are the foods most likely to contain them [17]. Work and home settings can add to this [1].

Your liver often sticks a small “tag” onto a mycotoxin. The tag helps it dissolve in water, so it can leave in your urine. Some toxins are also broken down into other forms. For example, citrinin mostly leaves the body as a breakdown product. Levels of that breakdown product in urine can be 3 to 17 times higher than citrinin itself [2]. So a good test looks for these tagged and broken-down forms too.

Scientists have used urine for years to track mycotoxins across whole populations. It’s seen as a simple, low-cost way to measure what people actually take in [1].

What happens to your urine sample in the lab?

The lab does four main jobs. It frees tagged toxins, cleans the sample, finds and measures each toxin, then adjusts for how watery your urine is. Each step affects your final number.

Step 1: Why does the lab add an enzyme?

The lab adds an enzyme to snip the tag off each toxin. This lets it measure the total amount, both tagged and untagged. Without this step, only the untagged toxin is counted.

This step isn’t perfect. In one study of 96 urine samples, the enzyme didn’t remove every tag, so the total was too low [3]. The type of enzyme matters too. When six expert European labs tested the same samples, labs using one enzyme got lower results than labs using another [4]. That’s one reason two labs can give different numbers for the same person.

That doesn’t make urine mycotoxin testing unreliable. It means who runs the test, and how consistently, matters. We use an established pathology lab accredited to the international ISO 15189 standard for medical laboratories across a wide range of its tests. Its mycotoxin panel uses LC-MS/MS, the same technique researchers rely on to measure low levels of mycotoxins in urine [5]. And because methods differ between labs, we always retest through the same lab, so any change in your results reflects a change in you, not a change in method.

Step 2: How is the sample cleaned up?

Urine contains thousands of other substances. So the lab first separates the mycotoxins from everything else. It’s a bit like sieving out just the parts it wants to measure. Labs have several standard ways to do this [5]. Some pass the sample through a tiny filter that holds on to the toxins while the rest washes away, and others simply dilute the sample before testing it. A cleaner sample can give a clearer reading.

Step 3: How does the lab find and measure each toxin?

Most modern labs use a machine called LC-MS/MS, which you can think of as having two parts. The first part sorts the substances in your sample, so they come out one at a time. The second part weighs each one. Every toxin has its own weight pattern, a bit like a fingerprint. This lets the machine tell the toxins apart. Researchers see it as the leading method to measure many mycotoxins at once [6].

It’s very sensitive. One official German lab method can measure some toxins at about 13 to 22 billionths of a gram in a litre of urine [7]. Some toxins are harder to measure, though. For gliotoxin, the same method needed about 100 times more before it could give a reliable number [7].

Step 4: Why are results adjusted for creatinine?

If you drink lots of water, your urine is more watery. The same amount of toxin then looks lower. To fix this, labs measure creatinine. This is a waste product your body makes at a fairly steady rate. The lab then gives each result per gram of creatinine.

Most labs do this, but not all do it the same way, and some don’t adjust at all [8]. Creatinine levels also vary with age, sex and body size [9]. Kidney problems can change both creatinine and toxin levels in urine [10]. That’s why your practitioner needs to know about any kidney condition.

What’s the difference between ELISA and LC-MS/MS tests?

How they find a toxin
ELISA uses antibodies that latch onto a toxin, a bit like a key fitting a lock. LC-MS/MS takes a different approach. It weighs each substance and reads its unique “fingerprint” to identify it.

How precise they are
Antibodies can sometimes stick to substances that look similar to the toxin they’re designed for, so ELISA is less precise and more prone to false readings. LC-MS/MS identifies each toxin directly, which makes it the more accurate of the two.

How many toxins each test covers
An ELISA test usually looks for one toxin or one group of toxins at a time. LC-MS/MS can measure many different toxins in a single sample.

Their place in research
ELISA was used in some earlier studies, but LC-MS/MS is now the current standard [6]

What does a urine mycotoxin test measure?

Healthpath’s urine mycotoxin test is run by our lab partner. It checks for 31 markers across 7 groups of toxins. It uses LC-MS/MS on a single urine sample and adjusts the results for creatinine.

The main groups include:

• Aflatoxins
• Ochratoxin A
• Zearalenone
• Trichothecenes type A, B and D
• Gliotoxin, made by a mould called Aspergillus fumigatus
• A miscellaneous group that includes Citrinin, Mycophenolic Acid and Chaetoglobosin A

How do you read your mycotoxin test report?

Each toxin is usually shown as a number per gram of creatinine. Next to it is the lab’s own cut-off. A result above the cut-off means your body was clearing more than the lab’s limit. It doesn’t mean you’ve reached a level known to cause harm.

This matters. There are no agreed normal ranges for healthy people. And no urine level has been shown to predict illness [13]. So cut-offs differ between labs. A “high” result at one lab may not be “high” at another.

At Healthpath your results will come with a video from your health practitioner explaining your results and your personalised plan. Here are a few tips for reading your report:

• Look at the pattern, not one number. Mostly food-related toxins tell a different story from building-related ones.
• Check the units. Adjusted and unadjusted results can’t be compared.
• Stick with one lab. If you retest, use the same lab, because methods and cut-offs differ.

What can a urine mycotoxin result tell you?

A result shows which mycotoxins your body has dealt with recently. It also gives a rough idea of how much. This can be useful, especially if you think you’ve spent time in a water-damaged building.

Timing matters. Urine mostly shows what you’ve taken in recently, and it can change from day to day. Some toxins stay much longer than others. In one human study, it took about 35 days for blood levels of ochratoxin A to halve [11]. So a single test is a snapshot, not the full picture.

In my clinic, I’ve seen many people with stubborn bloating, or SIBO that keeps coming back. Many had already tried diet changes, supplements and stress support without lasting change. A number of them had lived or worked in water-damaged buildings. This is what I’ve seen in practice, not research. Used well, a result can prompt a closer look at your home, work or diet. It also gives you a starting point to compare against later.

What can’t a urine mycotoxin test tell you?

A urine mycotoxin test can’t diagnose a health condition. It can’t tell you whether a toxin came from food or your home. It can’t show where mould is growing. And there’s no agreed “safe” range to compare it with.

Major health bodies agree on these limits:

• The US Centers for Disease Control and Prevention (CDC) notes that healthy people often have mycotoxins in their urine, because they’re in many foods. It says these tests aren’t approved for diagnosis [12]. This is why we recommend a low-mould diet before completing the test, because it reduces this concern.
• A 2023 German medical guideline says urine mycotoxin tests shouldn’t be used to diagnose indoor mould exposure [14][15]. That isn’t how we recommend using it either. Used alongside your history and symptoms, mycotoxin testing can provide one incredibly valuable piece of the puzzle.

Everyday exposure from food is common. A UK study found a cereal-related mycotoxin in the urine of 296 out of 300 adults (98.7%) [16]. A Spanish study found at least one mycotoxin in 55% of volunteers [5]. Again, this is why we recommend a low-mould diet before completing the test to remove this ‘background noise’.

These limits are why Healthpath pairs every result with a full health history and a practitioner review. If you’re worried about a building, get a professional damp or mould survey. UK guidance says to fix the cause of damp, not just clean off visible mould [19].

What is “provoked” mycotoxin testing?

Provoked testing means doing something before you collect urine to try to release more toxins. This might be taking glutathione, using a sauna or other “detox” steps. Some functional medicine practitioners use it.

Provoked testing isn’t part of the standard lab methods described here. There are no normal ranges for provoked results, or for unprovoked ones [13]. That makes a provoked result hard to make sense of. If you’re working with a practitioner, check with them before taking glutathione, binders or similar supplements before your test.

How should you prepare for a urine mycotoxin test?

Eat a low-mould diet for about three days. Check your supplements with your practitioner. Wait until you’re well. Then follow the collection instructions carefully.

1. Eat a low-mould diet for about three days. Cereals, nuts, spices, dried fruit and coffee can all contain mycotoxins [17]. Healthpath recommends cutting back on these for about three days before testing. This is Healthpath’s own approach, not an official standard. It aims to reduce the effect of food, so your result better shows other sources.
2. Check your supplements and medicines. Stop all non-essential supplements for 3 days before the test. If any of your supplements are prescribed under the care of a medical doctor or healthcare practitioner, please check with them first before stopping them. Never stop a prescribed medicine without talking to your GP.
3. Wait until you’re well. Collect your sample once you’ve got over any recent cold, flu or infection.
4. Collect and return your sample. Follow the kit instructions closely, including the time of day.

Who shouldn’t take a urine mycotoxin test right now?

Healthpath doesn’t currently recommend this test if you’re pregnant or breastfeeding because we couldn’t safely act on the results as many of the interventions are likely to centre around detoxification. Worried about mould while pregnant or breastfeeding? The most helpful steps are to fix any damp at its source and talk to your GP or midwife. The Healthpath team is happy to talk through what support may suit you now, and when testing might make sense later.

If you have kidney disease, or want to test a child, please talk to the Healthpath team before ordering. Creatinine levels are different in both cases, and this affects how results are read [9][10].

When should you see your GP first?

See your GP before thinking about a mycotoxin test if you have any of these. They need a proper medical check [18]:

• Weight loss you can’t explain
• Bleeding from your bottom, or blood in your poo
• Anaemia (a low red blood cell count) with no clear cause
• Looser or more frequent stools for more than six weeks, if you’re over 60
• Trouble breathing, or symptoms that are getting worse

A mycotoxin test should never delay these checks.

How does gut health relate to mycotoxin testing?

A mycotoxin test doesn’t check your gut. But gut testing can help explain the digestive symptoms that often show up alongside possible mould exposure.

Bloating, wind and changing bowel habits have many possible causes. They’re often linked to irritable bowel syndrome (IBS). Certain carbohydrates in everyday foods, called FODMAPs, can also cause these symptoms. NICE guidance supports diet changes for IBS, including a low-FODMAP diet with help from a trained professional [18]. It’s worth checking these common causes alongside anything mould-related, not instead of it.

Healthpath’s Ultimate Gut Plan includes a detailed stool test and a practitioner review of your results and symptoms. You also get a personal food, supplement and lifestyle plan. If bloating after meals is your main worry, the SIBO Test uses a breath test to check for small intestinal bacterial overgrowth (SIBO). Neither test measures mould or mycotoxins. But both can help explain what’s going on in your gut.

For more on mould and your health, see Who Should and Shouldn’t Take a Mycotoxin Test?, 7 Signs You Could Be Experiencing Mould Exposure and 9 Hidden Places You’re Exposed To Mould Every Day.

Frequently asked questions

How does a urine mycotoxin test work?

The lab frees mould toxins your body has tagged for removal and cleans the sample. A machine called LC-MS/MS then finds and measures each toxin. Finally, the lab adjusts the results for how watery your urine is [3][6][8].

Is urine mycotoxin testing accurate?

Modern tests can measure tiny amounts very precisely, down to billionths of a gram in a litre of urine [7]. The hard part is knowing what the numbers mean. That’s because there are no agreed levels that predict illness [12].

Why do different labs give different results?

Labs use different methods, toxin lists, enzymes and cut-offs. Not all of them adjust for how watery your urine is [4][8]. If you retest, use the same lab.

Can I have mycotoxins in my urine if I’ve never lived with mould?

Yes. Mycotoxins are common in everyday foods, so many healthy people have them in their urine. A UK study found a cereal-related mycotoxin in 98.7% of adults tested [16].

Can a urine mycotoxin test tell me where the mould is?

No. A result can’t tell you whether a toxin came from food or a building, or where mould is growing [12]. A professional damp or mould survey is the best way to check a building.

How long do mycotoxins stay in the body?

It depends on the toxin. Many leave within hours or days. Ochratoxin A takes much longer. In one human study, blood levels took about 35 days to halve [11].

Should I see my GP?

Yes. If you have ongoing symptoms, weight loss you can’t explain, blood in your poo, trouble breathing or symptoms that are getting worse, talk to your GP first [18].

This article is for educational purposes only. It is not intended to diagnose, treat, cure or prevent any disease. Please speak to a qualified healthcare professional before making changes to your health routine.

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