Urinary Toxin Testing: What It Can and Can't Tell You

What is urinary toxin testing?

Urinary toxin testing is a form of human biomonitoring: measuring environmental chemicals, or the substances the body turns them into (metabolites), in samples such as urine. Rather than guessing what you might be exposed to from what's in the air, water or food, it measures how much of a chemical actually got into your body.

In CDC's national testing, most chemicals measured in urine are ones that do not stay in the body a long time, usually measured as their metabolites. So a urine sample gives a snapshot of certain chemicals around the time you collect it.

Collecting urine carries very little risk, and CDC's national exposure report measures chemicals in urine as well as in blood and serum (part of the blood).

Urinary toxin testing is not meant for poisoning emergencies. If you think someone has been poisoned, call your local poison control center at 1-800-222-1222 right away, rather than waiting for a test result. For most chemicals, CDC notes, people are exposed to low levels in the food they eat, the water they drink and the air they breathe, and also from products and containers they use. Some environmental chemicals are known to cause disease or illness in people. But for most chemicals, CDC says, we do not know if low-level exposures like these affect our health.

Which toxins can a urine test detect?

Different labs and panels measure different groups of chemicals. At Avicenna Functional Medicine, we use Vibrant Wellness's tests, such as its Total Tox Burden. Vibrant describes the Total Tox Burden as "a comprehensive urine-based panel" and says it measures 87 toxins in all: 29 mycotoxins, 20 heavy metals and 38 environmental chemicals.

Vibrant reports the results in three panels: environmental chemicals, heavy metals and mycotoxins. They include:

• Pesticides and weedkillers (herbicides), such as glyphosate and atrazine.
• Phthalates, parabens and phenols such as BPA (bisphenol A). BPA is used to make polycarbonate plastics and epoxy resins, which may line some canned foods and drinks. Phthalates are used as liquid plasticizers and are found in hundreds of products, including some food packaging, cosmetics and fragrances. The National Institute of Environmental Health Sciences (NIEHS) lists both among chemicals that may disrupt the endocrine system: they may mimic, block or interfere with the body's hormones.
• Volatile organic compounds (VOCs): gases given off by certain solids or liquids, such as paints, many cleaning products and fuels. EPA says some VOCs may have short- and long-term health effects, but not much is known about the health effects of the levels usually found in homes.
• Heavy metals, such as lead, mercury, arsenic and cadmium.
• Mycotoxins: toxins made by certain molds, such as aflatoxins and ochratoxin A. Vibrant says the panel looks for mycotoxins "from both food and environmental molds."

Vibrant says it measures the mycotoxins and environmental chemicals with a lab method called tandem mass spectrometry (LC-MS/MS), and the heavy metals with a different method, inductively coupled plasma mass spectrometry (ICP-MS). Urine can be more or less dilute depending on how much you drink, so the lab also measures creatinine, a substance in urine that comes partly from muscle. Vibrant adjusts each result for creatinine "to account for urine dilution variations." CDC notes that results adjusted this way can also partly reflect differences in muscle mass or kidney function between people.

This doesn't mean the test shows every chemical you've ever been exposed to. It measures a set list of chemicals and compares your level of each with a reference range. Vibrant says some of its ranges are based on data from NHANES, a national CDC health survey, where available, and others on urine samples from 1,000 "apparently healthy" people. Vibrant also says ranges for children have not been established.

How is the test done?

Vibrant's test is done at home with a collection kit. Vibrant describes these steps:

• A clinician orders the test, and you receive a kit with instructions.
• You collect a urine sample first thing in the morning.
• You seal and store the sample as the instructions say, and ship it to the lab.
• The lab analyzes the sample for specific markers and reports your levels compared to a reference range.

Because you collect the sample at home, you don't need to visit a lab, and collecting urine carries very little risk. Follow the kit's instructions closely. For example, Vibrant says not to drink more than 8 ounces of water in the hour before you collect the sample, because urine that is too dilute may be rejected.

This kind of testing does not diagnose a disease. Instead, it provides exposure information that can be interpreted in the context of your symptoms and history.

For example, if your results show high levels of certain plasticizers, pesticides or solvents, our health coach, under clinician supervision, may talk with you about where these chemicals might come from in your home, work, hobbies or personal-care products, and how to cut back. The test itself can't tell you the source: CDC notes that urine levels reflect overall exposure from various sources but do not show specific sources or routes.

Mold toxin (mycotoxin) results need extra care. Low levels of mycotoxins are found in many foods, so mycotoxins are found in the urine of healthy people. CDC says mycotoxin levels that predict disease have not been established, and there is no FDA-approved test for mycotoxins in human urine. Vibrant's own report says measuring mycotoxins in urine is not an FDA-recognized way to diagnose mold exposure. CDC does not recommend testing body samples, such as urine, from people who live or work in water-damaged buildings. If you're worried about mold at home or work, CDC says a visual inspection is the first step, and that finding and fixing sources of moisture and cleaning or replacing moldy materials is essential.

Exposure to some of these chemicals is widespread. For example, NIEHS reports that a 2003–2004 CDC national survey found BPA in 93% of 2,517 urine samples from people age 6 and older. Some studies have linked urine levels of certain chemicals with health problems in groups of people. For example, NIEHS describes research that linked ordinary exposure to certain phthalates, as found in urine samples, with ADHD-related behaviors in the teen years. But finding a chemical in your own urine does not mean it is causing health effects or disease.

When a licensed clinician on our team reviews your results, the questions include:

• Are your levels elevated compared to typical reference ranges?
• Do the types of toxins detected make sense given your history, environment, or occupation?
• Is there a likely source you can reduce, and would a standard test, such as a blood lead test, or a referral to a specialist help?

The answers are rarely black-and-white. A toxin test result is one piece of the picture, read together with your history, symptoms and any standard test results, and never a diagnosis on its own. Vibrant itself says test results "should be used as one component of a healthcare provider's clinical assessment."

Urinary toxin testing isn't needed for everyone, and it can't find the cause of a health problem by itself. Two medical toxicology groups, the American College of Medical Toxicology (ACMT) and the American Academy of Clinical Toxicology (AACT), advise against heavy metal screening tests for symptoms that are not specific, unless there has been excessive exposure to metals. They say testing that isn't targeted can cause needless worry when a result falls outside a "normal" range, and that a person should have specific metal testing only if there is concern for a specific poisoning. Your provider may order heavy metal testing if you may have been exposed to heavy metals or have symptoms of heavy metal poisoning. MedlinePlus gives examples of how heavy metals can get into the body:

• Work: MedlinePlus lists construction, battery manufacturing, plumbing, and work with stained glass, pesticides or metal plating as jobs with a higher risk of heavy metal exposure.
• Home and food: living in an area with contaminated soil, eating foods with high levels of certain metals (such as mercury in fish), or drinking water from a building with lead pipes or older plumbing.

If you or someone in your household works with lead, tell your doctor. CDC recommends testing blood for lead. And because some environmental chemicals are found at measurable levels in much of the population, comparing your result with national data can show whether your exposure is unusual. But unusual does not mean harmful: CDC's national report does not determine whether levels are safe or linked to health effects.

The goal of urinary toxin testing is not simply to find chemicals; it is to look for practical, step-by-step ways to lower avoidable exposures. NIEHS notes that hormone-disrupting chemicals cannot be completely avoided, but you can make informed choices to reduce exposure. Depending on your results and history, your plan may include:

• Talking through possible sources, such as some cosmetics, food packaging, canned foods, cleaning products, pesticides, or lead pipes and older plumbing.
• Practical changes, where feasible. For example, NIEHS's tips for reducing BPA exposure in young children include not microwaving polycarbonate plastic food containers, using fewer canned foods, and choosing glass, porcelain or stainless steel containers, especially for hot food or liquids. EPA suggests more ventilation when using products that give off VOCs, and following label instructions carefully.
• Standard tests or a specialist when needed: for example, a blood lead test, or a referral to a medical toxicologist or a doctor who specializes in occupational and environmental medicine if a heavy exposure is likely, such as at work.

Vibrant's report colors each result by percentile: up to the 75th percentile of its reference group is green, the 75th to 95th percentile is yellow ("moderate exposure"), and above the 95th percentile is red ("high exposure"). This can help decide where to focus first. A red result suggests your level is unusual compared with that group, but it does not by itself mean the chemical is harming you. Vibrant's sample report also lists "detox suggestions," such as supplements, sauna sessions, activated charcoal and, for lead and arsenic, chelation therapy (medicines that bind metals so the body can pass them out). These are the lab's suggestions, not medical advice. The ACMT and AACT say promoting sweating doesn't remove toxins in amounts that matter for health, and they advise against chelation except for metal poisoning diagnosed with validated tests. We do not promise that chelation, sauna sessions, supplements or any "detox" program will remove toxins from your body or improve your health.

Biomonitoring itself is well established. CDC's National Report on Human Exposure to Environmental Chemicals presents biomonitoring data gathered from a national survey since 1999–2000. CDC uses these data, for example, to set reference values that doctors can use to tell whether a person has an unusual exposure, and to check how well public health efforts to reduce exposure to chemicals such as pesticides, lead and tobacco smoke are working.

Scientists widely use blood and urine to measure people's exposure to chemicals. But a 2014 scientific review explains that a person's level can vary from one sample to the next for reasons other than how much they were exposed. These include how quickly the body clears the chemical compared with how often exposure happens, when the sample is taken, and how much urine the person is making. Urine also isn't used for everything: chemicals that stay in the body a long time are usually measured in serum, and for lead, CDC recommends testing blood, where studies have given a good understanding of the health risks linked to different blood levels.

That said, urinary toxin testing has limitations. It reflects what is in your urine when you collect it, not everything you've been exposed to over your life. And detection of a chemical does not prove it is the cause of a specific symptom. Urine metal tests need particular care. The ACMT says urine testing for metals is common and accepted medical practice when done in an appropriate clinical context with proper, validated methods. But some practices give a chelating medicine before collecting urine, which is called a "provoked" or "challenge" urine test. Chelating drugs raise the amount of metals in urine even in healthy people, and the ACMT says post-challenge urinary metal testing "has not been scientifically validated, has no demonstrated benefit, and may be harmful." Vibrant says its heavy metal reference ranges come from national survey data where available, and otherwise from people who were "unprovoked, unmedicated and unsupplemented."

These are also laboratory-developed tests (LDTs): tests made and used within a single lab. Vibrant says each test was developed, and its performance characteristics determined, by its own lab, which is certified under CLIA, the federal program that regulates labs. Vibrant also says the tests have not been cleared or approved by the FDA. CLIA reviews whether a lab's test finds what it is meant to find, but it does not address clinical validity: how accurately a test identifies or predicts a health condition in a patient. Vibrant's own report says its heavy metals and environmental toxins panels do not show "absolute positive and negative predictive values" for any condition and that their "clinical utility has not been fully established." For these reasons, results should be read by a licensed clinician, together with your history, symptoms and standard tests.

Urinary toxin testing is not part of every plan. A licensed clinician on our team decides whether it is likely to be useful for you, and orders it if so. Here is what to expect:

• A discussion of your symptoms, environment and exposure history with our health coach, under clinician supervision.
• If testing is chosen for you, an at-home urine collection kit with clear instructions.
• Results from the lab: Vibrant says results are typically available within 7–10 business days, and its step-by-step guide says your report comes within 2–3 weeks.
• A follow-up visit with our health coach, under clinician supervision, to go over your results alongside your history and any standard tests, and to plan realistic, step-by-step ways to lower avoidable exposures.

Testing should never be about fear. A urine toxin test can show some of what you've been exposed to and point to practical ways to cut down avoidable exposures. It can't, on its own, tell you whether a chemical is causing your symptoms. To learn more, see our page on comprehensive toxin testing at Avicenna.

For more on this topic from independent sources:

1. Centers for Disease Control and Prevention (CDC). "National Report on Human Exposure to Environmental Chemicals (National Exposure Report)." https://www.cdc.gov/environmental-exposure-report/about/
2. Aylward LL, Hays SM, Smolders R, et al. "Sources of variability in biomarker concentrations." Journal of Toxicology and Environmental Health, Part B, 2014;17(1):45–61. https://doi.org/10.1080/10937404.2013.864250
3. Kawamoto M, Page E. "Notes from the Field: Use of Unvalidated Urine Mycotoxin Tests for the Clinical Diagnosis of Illness — United States, 2014." MMWR, 2015;64(06):157–158. https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6406a7.htm
4. American College of Medical Toxicology. "American College of Medical Toxicology Position Statement on Post-Chelator Challenge Urinary Metal Testing." Journal of Medical Toxicology, 2010;6:74–75. https://doi.org/10.1007/s13181-010-0039-0
5. American College of Medical Toxicology and American Academy of Clinical Toxicology. "Ten Things Physicians and Patients Should Question" (Choosing Wisely), 2013 and 2015. https://www.clintox.org/wp-content/uploads/2016/04/Choosing-Wisely-Recommendations_AACT_ACMT.pdf
6. MedlinePlus (U.S. National Library of Medicine). "Heavy Metal Testing." https://medlineplus.gov/lab-tests/heavy-metal-testing/
7. National Institute of Environmental Health Sciences (NIEHS). "Endocrine Disruptors." https://www.niehs.nih.gov/health/topics/agents/endocrine