patients: frequently asked questions

How long do the urine, blood, hair, and stool last as viable specimens?

Because urine, blood and stool specimens start to degrade in quality soon after collection, immediately shipping these samples to the laboratory ensures optimal results. If you cannot ship samples immediately, here are some guidelines regarding stability of the following biological specimens:

  • Urine samples are good for 5 days in the refrigerator and for extended periods in the freezer. This applies to all urine tests performed at The Great Plains Laboratory, Inc., except the Kryptopyrrole test. Urine for the Kryptopyrrole Test must be frozen immediately and received within 24 hours of the collection for accurate results.

  • The Amino Acid Plasma Test and Glutathione Test blood samples need to be shipped immediately. The laboratory must receive these samples within 24 hours of collection.

  • Serum samples are relatively stable and last for two weeks in the refrigerator and several months in the freezer. These serum tests include: Advanced Cholesterol Profile, C-Reactive Protein Test (hs-CRP), IgE Food and Inhalant Allergy Tests, IgG Food Allergy Test w/ Candida, Metals Whole Blood Test, Prealbumin Test, Streptococcus Antibodies Profile, Celiac Disease Test, and Vitamin D. The following serum tests have time-sensitive guidelines: Ceruloplasmin Test, Copper Test, Copper/Zinc Profile, Immune Deficiency Profile, and Zinc Test. The serum must be removed from the specimen within 4 hours of collection.

  • The Metals Red Blood Cell Test requires that the plasma must be removed and discarded from the specimen within 1 hour of collection.

  • The Essential Fatty Acids Test samples must be shipped within 2 days of collection and stored in the refrigerator.

  • Hair samples last indefinitely, assuming samples are protected from exposure.

  • Stool samples must be shipped Monday through Wednesday ONLY. Samples must be collected on two separate days (the yellow-topped vials at least 12 hours apart). All four stool specimens must be shipped together within 5 days of the first collection.

Are the results of the Gluten/Casein Peptide Test going to be accurate if the patient is on a gluten-free diet?  How long should the patient consume gluten and casein prior to having the test done?

The undigested peptides of gluten and casein will only be in the urine if the patient is consuming gluten and casein. It's up to you and your doctor to determine if it is appropriate to introduce the eliminated foods for the sake of this test. We do not recommend going back on these foods if the individual has responded well to the elimination of the food. If it is determined that the food will be reintroduced, a general guideline is to consume the food for one week prior to the Gluten/Casein Peptides Test.

Should the patient refrain from supplements prior to the Organic Acids Test (OAT)?

The OAT is designed to measure various metabolites in the body so that an understanding of the overall function can be assessed. It's up to you and your doctor to determine if you want an assessment of the body under the current metabolic conditions with supplements or without the aid of supplementation. Supplements themselves do not directly interfere with the OAT unless they contain apples, grapes, pears, or cranberries.

It is important to note that the body can take weeks to reestablish its metabolic functions after supplementation has been removed or introduced. If the supplements have recently been added or removed, the OAT will give a picture of the metabolism in transition and is difficult to assess from a clinical standpoint. If you determine that you want to cease or add supplementation, two weeks is the recommended period of time to wait before testing.

Are antibiotics and/or antifungals going to interfere with the Organic Acids Test (OAT)?

Antibiotics and antifungal will not directly interfere with the OAT unless they contain apples, grapes, pears or cranberries. It is important that the patient and practitioner consider why the test is being administered in order to determine whether or not the patient should refrain from antibiotics and antifungals. For example, a practitioner may want to know if a certain therapy is effective. In this example, it would be perfectly acceptable to remain on the therapy during collection. Separately, a patient may want to understand their metabolic condition without the aid of therapy. In this case, it is best to remove the antibiotics or antifungals for 1-2 weeks prior to testing.

Do I need a medical practitioner's approval to test with The Great Plains Laboratory, Inc. (GPL)?

A medical practitioner's approval is necessary if you are a resident of the United States. Many of the tests that we offer at GPL are also available through This service will provide a medical practitioner's signature for patients who wish to order testing and do not have a regular physician. An approved medical practitioner could be any of those listed in the following question.

What type of medical practitioners can authorize tests?

The Great Plains Laboratory, Inc. recognizes Medical Doctors (MD), Osteopathic Doctors (DO), Chiropractic Physicians (DC), Naturopathic Physicians (ND), Doctors of Philosophy in Psychology, Biochemistry, Toxicology, and Nursing (PhD), Doctors of Oriental Medicine (DOM), Licensed Acupuncturist (Lac), Physicians Assistants (PA), Nurse Practitioners (ARNP), Nurse Midwives (CNM), Certified Nutritionists (CCN), and Registered Dietitians (RD). It is the practitioner's responsibility to work within the rules and guidelines of the state for which they practice in. Each state has different regulations which govern the scope of practice for the practitioner. To obtain information about statutes and regulations for direct-to-consumer testing by state a practitioner may check with their state board of health for clarification about the specific restrictions regarding laboratory testing.

How do I find a doctor familiar with GPL testing?

Many of the tests that we offer at GPL are also available through which will provide a medical practitioner's signature for patients who order testing. The Great Plains Laboratory, Inc. has a national database with 3000+ medical practitioners. Please call our Customer Service staff at 1-800-288-0383 and a representative should be able to locate a medical practitioner in your area. Authorization does not have to come from your primary care physician; any licensed health professional can order testing in your state, including some chiropractors, naturopaths, nurse practitioners, or nutritionist/dietitians.

Where can I go to get blood drawn?

Visit our Blood Draw Services page for our recommended blood draw providers.

How do I find out if my insurance will cover your tests?

Coverage is determined by a number of factors. These factors include the type of procedure, the medical diagnosis, and the insurance policy guidelines. We encourage patients to call their insurance company to find out if their tests may be covered. It is helpful to provide procedure codes (also called CPT codes) and diagnostic codes (also called ICD-10 codes) to the insurance company when calling for pre-approval. The procedure codes are provided by the laboratory and are located on the page associated with the test on our website. The diagnostic codes are provided by the practitioner. Our laboratory can provide assistance for medical practitioners who need help locating a diagnostic code. For more information, please visit our insurance page.

I have already done testing with you, is my insurance information on file?

Yes, your insurance information is on file. If you have not tested with us in the last six months, we request that an updated copy of your insurance card be sent with your sample.

What about reimbursement for Medicaid and Medicare?

We can file for reimbursement with Medicare for some tests, but we do not accept Medicaid in any state.

I already had an Organic Acids Test done by another lab.  How is the Great Plains Laboratory Organic Acids Test different?

The Organic Acids Test offered by The Great Plains Laboratory, Inc. has 74 different markers including those for oxalate levels, Krebs Cycle abnormalities, neurotransmitter levels, nutritional deficiencies, antioxidant deficiencies, fatty acid metabolism, and yeast and clostridia overgrowth. Many of the compounds we use are patented for their specific use in the identification of yeast overgrowth and are only available through our lab. Our bacterial metabolites are also more specific than those tested by some other laboratories.

How will I understand what the test results mean?

Many of our test results do come with a written interpretation and a few do not. We encourage you to discuss the results with your physician, and submit an inquiry with your questions or concerns about the meaning of your test results. We do provide a free consultation with a nutritionist and biochemist to help you understand your results. The phone consultation can be scheduled for Tuesday, Wednesday, and Friday via the customer service department at 913-341-8949 during business hours. We can also provide consultations in Spanish, Italian, French, Portuguese, Japanese, and German languages.

Where do I find the price list?

The price of our tests is determined based upon the country and the test offered. Our prices are subject to change. Our most current domestic price list is found on the pricing page. International patients will need to contact us for pricing information.

How much does domestic shipping cost?

Shipping in the US is free. A FedEx prepaid billable stamp is sent along with all our test kits; thus you do not need to pay FedEx when sending samples to our laboratory. After sample collection please call 1-800-463-3339 (1-800-GoFedEx) for pick up. Remember to mention you have a FedEx billable stamp return.

How much are international shipping charges?

International patients are responsible for the cost of shipping test kits both into and out of the laboratory. Shipping charges will vary depending on the country. For an approximation of expedited cost for shipping specimen into the US, please see the International shipping charges. The price for shipping from the US is approximately half the cost listed. We have distributors in many countries that can provide our test kits to you at a reduced cost. Please contact us to find out if there is a distributor in your country.

Can I perform multiple urine tests using one specimen?

Yes, you can perform many of the urine tests with one urine sample. Each test has a specific volume requirement. The urine collection container holds about 70 mL. You will need a special collection jug to perform the timed & 24 hour urine tests. The timed & 24 hour urine tests require at least 40 mLs of urine.

Can I test my child who is not potty-trained?

Yes, The Great Plains Laboratory, Inc. provides pediatric collection tape-on bags to collect the urine from infants or children who are not potty trained. Please request the pediatric collection bags when ordering tests through Customer Service or online.

When should I expect results from the tests?

All of the tests have different turn around times. Most test results take between 1-3 weeks to be completed, (unless unforeseen conditions arise). Our standard procedure is to release a faxed copy of the test results to the authorizing medical practitioner and mail a hard copy to both the patient and the medical practitioner unless the medical practitioner has otherwise specified. In some cases the medical practitioner has requested the patient obtain results directly through the medical practitioner in which case the patient will not receive a copy of results in the mail.

If the test results indicate problems with foods, how long does the patient need to be on the diet?

It depends on the individual. IgG food allergies can change or disappear after a few months on a strict diet and yeast treatment, but some individuals still have allergies years after the food has been eliminated. Regular testing and professional guidance are especially helpful in predicting how an individual may respond to the reintroduction of foods. The Gluten/Casein Peptides Test may indicate that the patient has genetic enzyme deficiency or that mercury may be inhibiting the enzyme. Problems may appear any time the patient consumes gluten and casein.

Are the results of the IgG Food Allergy Test + Candida going to be accurate if the patient is on an elimination diet?  How long should the patient consume the eliminated foods prior to having the test done?

The IgG allergy can still show some reactivity up to two years after the food has been eliminated. Such positive reactivity is an indication that the individual is still predisposed to having undesirable effects from the offending foods. An IgG Food Allergy Test w/ Candida can still be helpful even when the individual is not consuming the foods in question. The antibodies can recur after the foods have been reintroduced because the immune system retains memory of foreign substances considered to be harmful. Patients should retest for IgG food allergies 6 weeks after the foods have been introduced and again 6 months later if the first test is negative. This recommendation is a guideline for patients to consider and should not take the place of medical advice.

If the patient is taking digestive enzymes, can he/she possibly tolerate some gluten and casein?

Digestive enzymes are an excellent way to supplement the diet and help improve the digestion in people who have a hard time eliminating these opioid peptides even while staying on the strict diet. Enzymes cannot substitute the diet; it can be compared with taking antidotes after poison, but they are an excellent way to save the situation if the patient has inadvertently eaten any gluten and casein or if gluten and casein may be hidden ingredients of any foods eaten.

Where can I get nutritional supplements that are specially designed for individuals with special needs and food allergies?

Many products are available at New Beginnings Nutritionals.

Do I need to travel to your lab to get tests done?

No, you do not have to come here. Test kits can be ordered online, by phone, by fax, or by a medical practitioner. The kits are usually mailed directly to the patient and will include everything the patient needs to collect and submit the specimen. Your test kit will include a pre-paid FedEx overnight clinical pack to return your specimen(s). International patients are responsible for the cost of shipping test kits both into and out of the laboratory. Shipping charges will vary depending on the country.

I've looked over the information here, but I still have questions...

Please submit a question or contact us, and we would be happy to help you select the appropriate testing for your individual situation or answer any other questions you may have. You can also learn more about us or our privacy practices on this website. You are encouraged to participate in our free web conferences where you can get detailed answers to many questions.