Test Overview

Gluten from wheat and related grains, and Casein from dairy products, contain peptides (short protein chains) called Gliadorphin (or gluteomorphin) and Casomorphin, respectively. These peptides have been shown to bind to opiate receptors in the brain, thus mimicking the effects of opiate drugs like heroin and morphine. This test measures the levels of these peptides excreted in the patient's urine.

Test Indications

Sample Collection

  1. Avoid soy products at least 1 week prior to testing.
  2. Collect at least 5 mL of first morning urine, preferably before any food or drink.
  3. Refrigerate immediately. Do not freeze.
  4. Ship with frozen gel pack.

Your doctor or lab may have different instructions that supersede the above.



Labs Performing Test

Name of LabLab CodeEstimated CostProcessing TimeComments
Great Plains  $1102-3 weeksCash discount and some insurance

Costs cited are subject to change and may be reduced by insurance or cash discounts and increased by sample collection fees.


Gliadorphin (from wheat and similar grains) and Casomorphin (from milk) have been shown to bind to opiate receptors in the brain, thus mimicking the effects of opiate drugs like heroin and morphine. These compounds have been shown to react with areas of the brain such as the temporal lobes, which are involved in speech and auditory integration.

Children with autism frequently seem addicted to wheat and dairy products.

In most cases, people who have food allergies to milk and wheat are also sensitive to Gliadorphin and Casomorphin. This may be because both the Gliadorphin/Casomorphin sensitivity and the wheat/milk food allergy may share a common cause: inadequate digestion or a leaky gut that allows undigested protein to pass directly from the gut to the blood circulation.

However, there are some people who may not show a food allergy to milk or wheat, but have the peptide problem and vice versa, so it may be a good idea to have both the peptide and food allergy testing done.

The IgG Food Allergy Test generally provides more information than the Gluten and Casein Peptide Test, but on the other hand the IgG Food Allergy Test requires a more invasive blood sample draw, whereas the Gluten and Casein Peptide Test only requires a urine sample.

Gliadorphin (Gluteomorphin)


  • A 7-amino acid peptide (tyr pro phe pro gly pro ile) derived from the milk protein casein, which is one of the major proteins in the milk of all mammals including cows, goats, and humans.
  • Present in high amounts in urine samples from people with autism, PDD, and schizophrenia. May also be elevated in other disorders such as chronic fatigue, fibromyalgia and depression based on anecdotal reports of symptom remission after exclusion of wheat and dairy.
  • Present in high amounts in urine samples from people with celiac disease. Dr. Weyrich notes that leaky gut is a characteristic of celiac disease.


    Dr. Weyrich hypothesizes that patients will exhibit a linear dose-response curve to Gliadorphin and Casomorphin, which suggests that symptom improvement may be linearly related to the extent to which dairy and wheat can be eliminated from the diet. This is in contrast to the extremely strict gluten-free diet required to successfully treat celiac disease.

    Dr. Weyrich hypothesizes that the opioid-like effects of Gliadorphin and Casomorphin may also reduce gut mobility, leading to constipation.

  • References

    Unless specifically noted above, references used in the construction of this web page include the following:

    [FDM] Lecture notes from Functional Medicine University.

    [SCNM] Lecture notes from Southwest College of Naturopathic Medicine.

    [UT] Lecture notes from the University of Tennessee graduate programs in Chemistry and Biochemistry.

    [GP] Great Plains Laboratory Physician Training lecture notes and documentation.