Functional Medicine Laboratory Tests for Environmental Toxicity Assessment

These five tests are fundamental in evaluating for various environmental toxin exposures, e.g. chemical, heavy metal, mold. The five tests are: Organic Acids Test (OAT), Toxic Non-Metal Chemical Profile (aka. GPL-TOX), Glyphosate Profile, GPL-MycoTOX Profile (aka. mold toxins) and Hair Metals (aka., Toxic & Essential Elements, Hair).

These tests all come from Great Plains Laboratory (GPL) and are available for ordering from Lab Tests Plus. Each test ordered through LTP comes with a detailed written review of findings of the relevant test markers and ‘action step’ suggestions. Ideally, all five tests should be done, but listed below are some additional considerations for each test if you are desiring to focus on certain exposures.

Organic Acids Test (OAT)

The OAT is a comprehensive assessment of various toxins linked to digestive yeast and bacteria toxins, digestive mold overgrowth, oxalate and various biochemical and mitochondrial imbalances. The OAT is a foundational test to have done and should not be skipped over for other testing. Other testing can be done, e.g. GPL-TOX, but in my opinion the OAT should always be done in combination with other tests.

Toxic Non-Metal Chemical Profile (aka., GPL-TOX Profile)

Toxic chemicals are significant factors in many chronic health conditions. Everything from gasoline additives, herbicides and pesticides can find their way into our water and food supply.

Many of these chemicals are problematic increasing the potential for various conditions such as cardiovascular disease, brain and nervous system disorders and even cancer. The OAT has certain chemical markers that are suggestive of chemical exposure, but the only way to know for sure which chemicals you are being exposed to is through testing. The GPL-TOX Profile is the test that should be done to identify various environmental chemicals.

Glyphosate Profile

Glyphosate is a chemical found in a popular herbicide used throughout the world. It is heavily used in soy and corn crops but is often used for other farming purposes too. There is growing evidence regarding the toxicity of glyphosate and the negative impact on health. The Glyphosate Profile from Great Plains Laboratory is a nice complement test to do along with the GPL-TOX Profile.

Glyphosate is known to alter the normal bacteria in our digestive system which increases the potential for opportunistic yeast and bacterial imbalances. Many times, high glyphosate is seen along with elevated clostridia bacteria markers, such as HPHPA and 4-Cresol, which are detected on the Organic Acids Test (OAT).

GPL-MycoTOX Profile

Mold toxins, called mycotoxins, are some of the most toxic compounds produced in the natural world. They can cause severe tissue damage within the body leading to kidney, liver, immune and nervous system diseases, as well as causing cancer.

Mycotoxins can find their way into various foods such as grains, fruit, meats and dairy and are commonly acquired from mold growth from water damaged building material. The Organic Acids Test (OAT) provides a few markers that indicate an overgrowth of mold in the digestive system, but it doesn’t identify which mycotoxins are present. The only way to do this is through the GPL-MycoTOX profile.

If you have concerns about mold exposure, the GPL-MycoTOX Profile should be done in combination with the OAT.

Hair Metals (aka., Toxic & Essential Elements, Hair)

Heavy metals such as Arsenic, Lead and Mercury can be acquired from various sources, e.g. grains, chicken, fish, water, contaminated soil and lead to wide variety of health disorders. For example, Lead exposure is a cause of brain and nervous system damage and is associated with various mental health conditions, including attention deficit hyperactivity disorder (ADHD) and behavioral problems in children.

A hair analysis is a non-invasive test to assess for heavy metal exposure. It is easy to do for both adults and children and provides information regarding past exposure to heavy metals. It also provides a useful way of measuring for certain mineral imbalances such as lithium, selenium and zinc. It is recommended to do the Organic Acids Test too along with Hair Metals testing.


Ideally, all five tests should be done for the most comprehensive assessment. However, if you are looking to combine just certain tests for specific purposes the following combinations are suggested.

OAT + GPL-TOX + Glyphosate
OAT + Hair Metals
OAT + Hair Metals + GPL-TOX