Lab collection FAQs

Exercise that increases heart rate may affect catecholamines (hormones made by the adrenal glands) and maybe serotonin. Heavy exercise can lower Glutamate (an excitatory neurotransmitter in the brain involved in normal brain function) and GABA (a calming neurotransmitter). Heavy exercise will also induce a stress response, raising cortisol (a “stress hormone” produced by the adrenal gland).  This may affect your laboratory results.

Caffeine is a stimulant and will boost catecholamines and cortisol. This may then boost excitatory neurotransmitters and suppress inhibitory (Serotonin & GABA) function. Caffeine may also increase serotonin levels. This could affect your laboratory results.

Some medications or supplements may affect certain neurotransmitters. We ask that you list them on the questionnaire in case levels are too high or low. We also ask that you list approximately how long you have been taking them and what dosage you are taking. Do NOT discontinue use of your medications without consultation with your healthcare provider.

Yes, you do not need to alter your normal routine. About 1 hour after rising is your first morning sample, no matter what hour the clock says.

Neurolab prefers that all samples are collected within the same day (24-hour period). However, if you are unable to collect all of your samples on the same day, there are two acceptable scenarios.

Scenario 1: If urine is collected on Day 1 and all 4 saliva samples are collected on Day 2, or vice versa, that will be fine.

Scenario 2: The patient attempts to collect the urine and 4 saliva samples throughout the course of one day.  The patient successfully collected the urine sample, but only collected 3 saliva samples and fell asleep before collecting their 4th saliva sample.  The 4th sample can be collected the following day but ONLY if it is collected at the same time of day that it should have been collected on the previous day.

Although it’s ideal to get all of your samples done in the same day, we will still accept your urine specimen on a different day that when you collected your 4 saliva samples. It should be collected as close as possible to the same date as the saliva samples were collected. Just make sure and note the date and time of the collection and label accordingly on the collection tube and questionnaire. *Note: Our laboratory will only accept samples that have been collected within 30 days. If you send in any samples that are more than 30 days old, we cannot process your results and we will inform your practitioner to recommend that you submit a new test.

Do NOT discontinue use of your medications or supplements without consultation with your healthcare provider. Neurolab does not require patients to refrain from taking any medications or supplements prior to collecting their samples. Some medications or supplements may affect certain neurotransmitters. We ask that you list them on the questionnaire in case levels are too high or low. We also ask that you list approximately how long you have been taking them and what dosage you are taking.

Smelling a lemon traditionally is the most effective way to generate saliva. Saliva can also be collected by (pooling it) within the mouth for short periods to accumulate enough saliva for collecting a sample. Some patients have also reported success generating saliva by smelling/thinking about/cooking one of their favorite foods. When rinsing your mouth prior to each saliva collection, try using warm water rather than cold water. Most importantly, relax. You don’t have to fill the tube immediately. It may take some people longer than others to generate saliva.

Urine stabilizer looks like clear liquid droplets or condensation with a miniscule cotton ball inside of the urine tube. Ensure the cotton ball is not stuck to the inner lid. if it is, just shake it down before opening. Since the urine collection requires mixing your sample with the stabilizer in the tube, you cannot rinse the urine tube or recollect a “mistake” urine sample by emptying the tube and recollecting in the same tube. Note: Saliva sample tubes (with colored caps) do not have a stabilizer and can be rinsed and re-used if necessary.

As long as the specimens have been frozen, you may go ahead and send in your specimens. If it has not been in the freezer, contact your healthcare provider for instructions on getting a new kit. Ideally, it is best to submit the tests as close as possible to the sample collection date so that they don’t expire and you can obtain results faster. We require you submit your samples no later than 30 days after you collect your sample.

The first morning urine is usually too concentrated for testing and will produce skewed results. By collecting your SECOND urine of the day (typically 2 to 3 hours after waking), we get a picture of both the inhibitory and excitatory systems as they get ready to meet the day.

Freezing is to control interfering bacteria. We recommend that you freeze each sample immediately upon collection and that you keep your specimens be frozen for at least 4 hours before sending them in. If necessary, you may leave your specimens in the freezer over night/weekend before sending them in.

They are good for up to 30 days in the freezer.

If you are taking the HPA-G, HPA or HP profile, the only thing expired in your kit is the urine tube. All you need is a replacement urine tube. The quickest way to get a replacement urine tube is directly from your healthcare provider. If that is not a valid option, you can call our customer support at: 866.670.5705 ext 2 and we can send a replacement urine tube directly to you.

We don’t suggest it. Alcohol has dehydrating properties and can affect the results. IF you choose to consume alcohol of any amount, please note it on the patient questionnaire. Remember: Do not drink more than 8 oz of fluid prior to your urine collection, and do not drink anything (other than water) for at least one hour prior to each saliva collection.

For any sex hormone testing, if a transgender person has a menstrual cycle, collection should be on day 19, 20, or 21 of a normal 28-day cycle.

You should collect during the mid-luteal phase of your cycle. This is generally 7-9 days prior to menstruation.

If you are taking birth control pills, day 1 of your period would be day 1 of the active pills in your monthly birth control pack. Collect your samples on day 19, 20, or 21 of the active pills in the pack.



Inhibitory Neurotransmitter


One of our feel-good neurotransmitters; Low levels of serotonin may relate to occasional symptoms like moodiness, sleep issues, and carb cravings. 

Learn why and how to test serotonin levels