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Neurotransmitter Testing

Labrix sets new standards in laboratory medicine. Labrix neurotransmitter testing utilizes HPLC Triple Quadrupole MS/MS technology which is proving to be the most sensitive and accurate methodology for measuring urinary neurotransmitters. Labrix testing is higher sensitivity and has stronger results reproducibility than has been available through other methodologies; this gives you far greater confidence in the reported results. In addition to reliability and accuracy, Labrix leads the pack in terms of guaranteed turnaround times, easy to use kits, clinical support for professionals, and top of the line customer service.

The NeuroEndocrine Connection

Neurotransmitters are the brain chemicals that facilitate the transmission of signals from one neuron to the next across a synapse. Neurotransmitters work with receptors in the brain to influence and regulate a wide range of processes such as mental performance, emotions, pain response and energy levels. Functioning primarily in the Central Nervous System (CNS), neurotransmitters are the brain’s chemical messengers, facilitating communication among the body’s glands, organs, and muscles. Numerous clinical studies have shown that inadequate neurotransmitter function has a profound influence on overall health and well-being. In fact, imbalances in certain neurotransmitters are associated with most of the prevalent symptoms and conditions seen in practitioners offices today.

  • Mood disorders; depression, anxiety
  • Adrenal dysfunction; fatigue, insomnia
  • Loss of mental focus; ADD, ADHD, cognitive fog
  • Addiction and dependency
  • Hormonal imbalances; E2 dominance, E2 deficiency, low androgens
  • Loss of appetite control; insulin resistance

Compounding these symptoms of imbalance are the myriad of bioactive substances like caffeine, alcohol and nicotine and many of the medications used to manage these conditions as well as some cholesterol lowering medications. These substances and medications can contribute to neurotransmitter depletion and resulting symptoms by suppressing or artificially stimulating neurotransmitter receptor function.

When functioning properly the neurotransmission system has natural checks and balances in the form of excitatory and inhibitory neurotransmitters. These are classified according to their effects on postsynaptic membranes (receptor sites). Excitatory neurotransmitters cause depolarization of the membrane and promote an action potential. Inhibitory neurotransmitters cause hyperpolarization and depresses or inhibit an action potential.

Putting It All Together

Identifying and managing neurotransmitter imbalances is facilitated with a noninvasive urinary test. Testing provides a tool to understand each patient’s specific neuroendocrine imbalances, which can be corrected with nutraceuticals, BHRT, diet, and lifestyle interventions.

Information on this website identifies numerous symptoms and conditions associated with neurotransmitter imbalances. It is especially important to understand that there are agonistic/antagonistic interrelationships of the neurotransmitters with adrenal hormones and sex hormones. Changes in sex hormones and adrenal hormones can lead to neurotransmitter imbalances. And at the same time, neurotransmitter imbalances will affect hormone production and function. Testing both neurotransmitters and hormones provides a comprehensive view of the body’s functional neuroendocrine status, and brings to light additional factors that may be contributing to symptoms.

Neurotransmitter testing may be applicable to both male and female patients. Expression of the following symptoms can indicate neurotransmitter imbalances. Review of the neurotransmitter test menu will help determine which test should be ordered.

  • Depressed mood
  • Anxiety
  • Adrenal dysfunction
  • Fatigue
  • Poor sleep
  • Loss of mental focus, or cognitive fog
  • ADD and ADHD
  • Addiction or dependency
  • Loss of appetite control
  • Compulsive behavior
  • Cravings
  • Low libido
  • Sexual dysfunction

Adrenal hormones, sex hormones, and neurotransmitters are functionally interrelated. Changes in sex hormones and adrenal hormones can lead to neurotransmitter imbalances. In turn, neurotransmitter imbalances can affect hormone function. Including neurotransmitters with hormone panels provides a more comprehensive view of the body’s functional neuroendocrine status, this interrelationship, and the associated factors that may be contributing to symptoms.

Below is an overview of six important neurotransmitters and their respective roles in various symptomatic conditions. Refer to the neurotransmitter test menu for panel options.

SEROTONIN is a key neurotransmitter that is involved in the regulation of sleep, appetite and aggression. Serotonin imbalance is a common contributor to mood problems, and pharmacologic agents that alter serotonin levels are among the most commonly used class of drugs prescribed for anxiety and depression.

High stress, insufficient nutrients, fluctuating hormones and the use of stimulant medications or caffeine can all contribute to the depletion of serotonin over time. When serotonin is out of range, depression, anxiety, worry, obsessive thoughts and behaviors, carbohydrate cravings, PMS, difficulty with pain control, and sleep cycle disturbances can result.


GABA is the major inhibitory neurotransmitter found in the CNS and, as such, is important for balancing excitatory action of other neurotransmitters. High levels of GABA may be a result of excitatory overload, or a compensatory mechanism to balance the surplus excitatory neurotransmitter activity. These high levels result in a ‘calming’ action that may contribute to sluggish energy, feelings of sedation, and foggy thinking. Low GABA levels are associated with dysregulation of the adrenal stress response. Without the inhibiting function of GABA, impulsive behaviors are often poorly controlled, contributing to a range of anxious and/or reactive symptoms that extend from poor impulse control to seizure disorders. Alcohol as well as benzodiazepine drugs act on GABA receptors and imitate the effects of GABA. Though these substances don’t cause an increase in GABA levels, understanding their mechanism can give us additional insight into the effects of GABA.


DOPAMINE is largely responsible for regulating the pleasure reward pathway, memory and motor control. Its function creates both inhibitory and excitatory action depending on the dopaminergic receptor it binds to. Memory issues are common with both elevations and depressions in dopamine levels. Caffeine and other stimulants, such as medications for ADD/ADHD, often improve focus by increasing dopamine release, although continual stimulation of this release can deplete dopamine over time.

Common symptoms associated with low dopamine levels include loss of motor control, cravings, compulsions, loss of satisfaction and addictive behaviors including: drug and alcohol use, smoking cigarettes, gambling, and overeating. These actions often result from an unconscious attempt to self-medicate, looking for the satisfaction that is not occurring naturally in the body.

Elevated dopamine levels may contribute to hyperactivity or anxiety and have been observed in patients with schizophrenia. High dopamine may also be related to autism, mood swings, psychosis and attention disorders. L-DOPA is a precursor to dopamine, and is used therapeutically for low dopamine conditions such as Parkinson’s disease. These medications can cause elevations in dopamine.


NOREPINEPHRINE, also called noradrenaline, is an excitatory neurotransmitter produced in the CNS, as well as a stress hormone produced in the adrenal medulla. Norepinephrine is involved in a wide variety of actions including attention, focus, regulating heart rate, affecting blood flow, and suppressing inflammation. Involved in arousal, it prepares the body for action by relaying messages in the sympathetic nervous system as part of the autonomic nervous system’s fight-or-flight response. High levels of norepinephrine are often linked to anxiety, stress, elevated blood pressure, and hyperactivity, whereas low levels are associated with lack of energy, focus, and motivation.


EPINEPHRINE, often better known as adrenaline, is synthesized from norepinephrine in both the CNS and the adrenal medulla. Much like norepinephrine, this excitatory neurotransmitter helps regulate muscle contraction, heart rate, glycogen breakdown, blood pressure and more, and is heavily involved in a stress response. Elevated levels of epinephrine are often associated with hyperactivity, ADHD, anxiety, sleep issues, and low adrenal function. Over time, chronic stress and stimulation can deplete epinephrine stores leading to difficulty concentrating, fatigue, depression, insufficient cortisol production, chronic stress, poor recovery from illness, dizziness and more.


GLUTAMATE is an excitatory neurotransmitter and is considered to be the most abundant neurotransmitter in the nervous system. Glutamate is involved in most aspects of normal brain function including cognition, memory and learning, although high levels of glutamate can cause excitotoxicity, a process where nerve cells are damaged by excessive stimulation. Elevated glutamate levels are commonly associated with panic attacks, anxiety, difficulty concentrating, OCD and depression, whereas low glutamate levels may result in agitation, memory loss, sleeplessness, low energy levels and depression.


GLYCINE is inhibitory and plays dual roles as both a neurotransmitter and an amino acid that serves as a building block of proteins. Glycine improves sleep quality, calms aggression, and serves as an anti-inflammatory agent. Glycine has been shown to boost mental performance and memory. Elevated glycine levels may be associated with compromised cognitive processing. Low levels of glycine may contribute to poor sleep, poor cognitive function, and issues with memory.


HISTAMINE is an excitatory neurotransmitter involved in the sleep/wake cycle and inflammatory response. Histamine plays a dual role in the body as both a neurotransmitter and immunomodulator increasing metabolism, promoting wakefulness, attention, circadian rhythms, learning, and memory. Elevated levels may be associated with allergy-like symptoms, gastro-intestinal concerns, and inflammation. Elevated histamine can interfere with sleep, contributing to insomnia. Low histamine may affect digestion and appetite control, learning, memory, and mood, and may result in drowsiness.


PEA (PHENETHYLAMINE) promotes energy, elevates mood, regulates attention and aggression, and serves as a biomarker for ADHD. Elevated PEA may contribute to anxiety, with very high levels having amphetamine-like effects. Elevated PEA levels may be associated with higher cortisol levels. Low PEA may be associated with ADHD, depression, Parkinson’s disease and bipolar disorder.