Neurotransmitters Testing (Neuro Advanced Profile) + Toxic & Essential Elements Profile (Dried Urine Elements)

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Neurotransmitter testing is a diagnostic procedure used to measure the levels of various neurotransmitters in the body. Neurotransmitters are chemical messengers that facilitate communication between nerve cells in the brain and throughout the nervous system. They are crucial in regulating mood, behaviour, cognition, and other essential functions. This testing can provide valuable insights into the balance and activity of neurotransmitters within an individual's system. It can help identify imbalances or deficiencies in specific neurotransmitters that may be associated with various neurological and psychiatric conditions, such as depression, anxiety, attention deficit hyperactivity disorder (ADHD), and more. 

Neuro Advanced Profile + Toxic & Essential Elements Profile (Dried Urine Elements) in dried urine containing the following 34 tests:

  • Gamma-aminobutyric acid (GABA),
  • Glutamate (Glu),
  • Glycine (Gly),
  • Dopamine (DA),
  • Epinephrine (Epi),
  • Norepinephrine (NE),
  • Histamine (HIST),
  • Serotonin (5-hydroxytryptophan (5-HT),
  • Phenethylamine (PEA),
  • Dopamine metabolites (DOPAC),
  • Homovanillic acid (HVA),
  • 5-hydroxyindole 3-acetic acid (5-HIAA),
  • Normetanephrine (NMN),
  • Vanillylmandelic acid (VMA),
  • Tryptophan (Trp)
  • Kynurenine (Kyn)
  • Kynurenic acid (KynAc)
  • 3-Hydroxykynurenine (3- OHKyn)
  • Xanthurenic acid
  • Taurine
  • Glutamine
  • Histidine
  • N-Methylhistamine
  • Tyrosine
  • Tyramine
  • Creatinine (Crtn).

Add On Toxic & Essential Elements Profile (Dried Urine Elements)

Toxic and Essential Elements Profile is a comprehensive testing solution that analyses eight key elements in dried urine spots, providing valuable insights into your thyroid health. The elements tested include: 

  • Iodine (I): Iodine is an essential trace element required for the production of thyroid hormones. Adequate iodine levels are crucial for proper thyroid function, metabolism, and overall growth and development.
  • Bromine (Br): Bromine is a halogen that can compete with iodine for receptor sites in the thyroid gland. Excessive bromine exposure may disrupt thyroid hormone synthesis and lead to thyroid dysfunction.
  • Selenium (Se): Selenium is an essential mineral that plays a crucial role in thyroid hormone metabolism and antioxidant defence mechanisms. Adequate selenium levels are necessary for optimal thyroid function and to protect the thyroid gland from oxidative stress.
  • Arsenic (As): Arsenic is a toxic element that can be found in various environmental sources. Prolonged exposure to arsenic has been linked to adverse effects on the thyroid gland, including disruption of thyroid hormone synthesis and metabolism.
  • Mercury (Hg): Mercury is a highly toxic element that can accumulate in the body over time, primarily through exposure to contaminated fish and dental amalgams. Elevated mercury levels have been associated with thyroid dysfunction and impaired thyroid hormone production.
  • Cadmium (Cd): Cadmium is a toxic heavy metal commonly found in industrial environments and cigarette smoke. High cadmium levels have been linked to an increased risk of thyroid disorders, including goiter and thyroid cancer.
  • Lithium (Li): Lithium is a naturally occurring element that is commonly used as a medication for certain psychiatric conditions. It can affect thyroid function by altering thyroid hormone synthesis and metabolism.
  • Creatinine (Crtn): Creatinine is a waste product produced by the breakdown of creatine in muscles. Measuring creatinine levels in dried urine spots helps to assess the concentration of other elements, as it serves as a marker of urine concentration.

Key Features

  • Comprehensive Assessment: Neurotransmitter testing provides a comprehensive evaluation of multiple neurotransmitters, allowing for a more detailed understanding of an individual's neurochemical profile. 
  • Objective Assessment: Neurotransmitter testing objectively measures neurotransmitter levels in the body. This can help healthcare providers obtain a more accurate and quantitative understanding of an individual's neurochemical profile, supplementing subjective clinical evaluations.
  • Personalised Treatment Approach: By identifying specific neurotransmitter imbalances, testing helps healthcare providers develop personalised treatment strategies tailored to the individual's needs. This can include targeted medication selection, nutrient supplementation, lifestyle modifications, and other interventions to restore balance and optimise neurotransmitter function.
  • Diagnostic Aid: Neurotransmitter testing can assist in diagnosing and understanding certain mental health conditions. It can provide objective data that complements clinical assessments, helping clinicians differentiate between disorders and contributing factors. For example, it may reveal imbalances associated with depression, anxiety, ADHD, or other neurological and psychiatric conditions.
  • Targeted Interventions: Neurotransmitter testing can help identify specific deficiencies or imbalances that may be contributing to symptoms or health conditions. This information allows for more targeted interventions to restore balance and optimise neurotransmitter function.
  • Monitoring Treatment Progress: The testing can be used to monitor the effectiveness of treatment interventions over time. By measuring neurotransmitter levels before and during treatment, healthcare providers can gauge the impact of interventions and make necessary adjustments to optimise outcomes.
  • Differential Diagnosis: Neurotransmitter imbalances can manifest in various mental health conditions and neurological disorders. Neurotransmitter testing can aid in the differential diagnosis process, helping healthcare providers differentiate between different conditions and contributing factors.
  • Individualised Nutritional Support: Neurotransmitter testing may reveal deficiencies or imbalances that can be addressed through targeted nutrient supplementation. Individuals can be provided with personalised recommendations to support optimal neurotransmitter function by identifying specific nutritional needs based on neurotransmitter levels.
  • Holistic Approach: Neurotransmitter testing promotes a holistic mental health and well-being approach. It recognises the interplay between neurochemistry, lifestyle factors, and environmental influences, helping to guide treatment decisions beyond pharmaceutical interventions alone.
  • Suitability: All our tests including the Neurotransmitters test are suitable for both adults and children.
  • Collection of Samples: Non-invasive at-home sample collection – 4 strips of dried urine collected throughout the day and ease of storage and shipment.
  •  Result: Accurate, timely, and dependable results. Personalised, clinical literature-cited report to explain the results and provide treatment considerations.
  • Delivery: Free delivery in the UK 
  • Shipping: Customers are responsible for shipping their samples to the laboratory. 
  • No Additional Fee: The test kit includes a laboratory fee: no additional laboratory cost or tax.
  • Test Sample Report: Click to see >> Advanced Neurotransmitter Test Report and also see >>   Toxic and Essential Elements Test Sample Report
  • Expiry Date: The test must be used within 12 months after the purchase date. 
  • Test Result Report: You will receive your test result via email within 3-5 working days after the Laboratory receives your sample. On your test result, you will find your hormone levels in graphics and numbers, which makes it easy to understand. You will also find the Laboratory's comments made by Specialist PhD. Dr suggests balancing your hormones if there are any imbalanced hormones and what to do next. 
The Test Kit pack includes
  • Test Requisition Form includes Symptom Checklist
  • Requisition Form to complete, including your personal and medical history
  • Contains collection instructions
  • Cards for collecting a dried urine sample
  • Instructions on How to Use Collection Kit
  • Return Envelope
  • Shipping instruction
Neurotransmitters are vital in facilitating communication between nerve cells (neurons) in the brain and throughout the nervous system. Here are some critical roles of neurotransmitters:
  • Regulation of Mood and Emotions: Neurotransmitters such as serotonin, dopamine, and norepinephrine regulate mood, emotions, and feelings of pleasure and reward. Imbalances in these neurotransmitters have been associated with mood disorders like anxiety, depression and bipolar disorder.
  • Control of Motor Functions: Neurotransmitters like acetylcholine, dopamine, and gamma-aminobutyric acid (GABA) play a crucial role in controlling and coordinating motor functions. They help regulate muscle movements, balance, and coordination.
  • Cognitive Function and Learning: Neurotransmitters like glutamate, acetylcholine, and dopamine contribute to cognitive function, learning, and memory. They facilitate the transmission of signals in brain regions responsible for cognition, attention, and information processing.
  • Regulation of Sleep and Wakefulness: Neurotransmitters such as serotonin and norepinephrine help regulate sleep and wakefulness cycles. They influence the timing and quality of sleep, as well as the transition between different sleep stages.
  • Modulation of Pain Perception: Certain neurotransmitters, such as endorphins and enkephalins, are involved in the modulation of pain perception. They can inhibit or dampen the transmission of pain signals, resulting in pain relief.
  • Autonomic Functions: Neurotransmitters regulate various autonomic functions, including heart rate, blood pressure, digestion, and respiration. Neurotransmitters like acetylcholine and norepinephrine are mainly involved in the autonomic nervous system's control over these functions.
  • Regulation of Appetite and Satiety: Neurotransmitters such as serotonin and neuropeptide are involved in regulating appetite, satiety, and food intake. Imbalances in these neurotransmitters can contribute to eating disorders and weight management issues.

Overall, neurotransmitters play a vital role in numerous physiological and psychological processes, maintaining the proper functioning of the nervous system and influencing various aspects of human behaviour and experience.


Imbalances in neurotransmitters can have significant effects on mental and physical health. Here are some potential outcomes of neurotransmitter imbalances:

  • Mood Disorders: Alterations in neurotransmitter levels, particularly serotonin, dopamine, and norepinephrine, are associated with mood disorders such as depression, bipolar disorder, and anxiety disorders. Low levels of serotonin, for example, have been linked to depressive symptoms, while imbalances in dopamine can contribute to mood swings and instability.
  • Cognitive Impairment: Disruptions in neurotransmitter balance can impact cognitive function, memory, attention, and information processing. For instance, deficiencies in acetylcholine have been associated with memory impairment and cognitive decline, as seen in conditions like Alzheimer's disease.
  • Sleep Disturbances: Imbalances in neurotransmitters can affect the regulation of sleep-wake cycles. Insufficient serotonin or disruptions in the balance of other neurotransmitters can lead to sleep disorders, such as insomnia or excessive sleepiness.
  • Neurological Disorders: Neurotransmitter imbalances have been implicated in various neurological conditions. For example, disruptions in dopamine function are associated with Parkinson's disease, a disorder characterised by motor symptoms, while abnormalities in glutamate and GABA transmission are implicated in epilepsy and seizures.
  • Impaired Motor Function: Imbalances in neurotransmitters involved in motor control, such as dopamine, can lead to motor abnormalities. Parkinson's disease, for instance, is characterised by a deficiency of dopamine, resulting in movement difficulties, tremors, and muscle rigidity.
  • Addiction and Substance Abuse: Neurotransmitter imbalances, particularly involving dopamine, play a significant role in addiction and substance abuse. Substance use can alter neurotransmitter levels and affect reward pathways in the brain, leading to dependence and addiction.
  • Hormonal Imbalances: Neurotransmitters can influence the release and regulation of hormones in the body. Imbalances in neurotransmitters may disrupt the normal functioning of the endocrine system, affecting hormone production, metabolism, and various physiological processes.
  • Digestive Disorders: Neurotransmitter imbalances, such as disruptions in serotonin levels, can impact the digestive system. Low serotonin levels have been associated with gastrointestinal issues like irritable bowel syndrome (IBS) and other functional gastrointestinal disorders.

Neurotransmitters & Your Health

  • Do you suffer from anxiety or depression?
Anxiety and Depression: Imbalances in neurotransmitters such as serotonin, norepinephrine, and dopamine have been associated with anxiety and depression. Low levels of serotonin, in particular, have been linked to feelings of anxiety and low mood, while imbalances in dopamine and norepinephrine can also contribute to these conditions.
  • Do you struggle to fall asleep or stay asleep throughout the night? 
Sleep Disorders: Neurotransmitters play a role in regulating sleep-wake cycles. Imbalances in neurotransmitters like serotonin and melatonin can disrupt the sleep process, leading to difficulties falling asleep, staying asleep, or experiencing restful sleep. For example, low serotonin levels can contribute to insomnia, while disturbances in melatonin can affect the timing of sleep.
  •  Has your libido fizzled?
Libido: Neurotransmitters influence sexual desire and function. Dopamine, in particular, plays a role in the brain's reward and pleasure pathways, including sexual pleasure. Imbalances in dopamine or other neurotransmitters can contribute to a decrease in libido or sexual dysfunction.
  • Women, do you dread the weeks before your period?

Premenstrual Symptoms: Changes in neurotransmitter levels, such as fluctuations in serotonin and gamma-aminobutyric acid (GABA), can contribute to premenstrual symptoms in women. Low serotonin levels, in particular, have been linked to mood swings, irritability, and other emotional symptoms experienced before menstruation.

If you answered yes to these questions, an underlying neurotransmitter imbalance might be the cause. Simple testing may help you find personalised solutions.

Neurotransmitters & Their Impact
Neurotransmitters are chemical messengers used by the nervous system to relay information from one nerve to another. The body relays information through the nervous system about anything it experiences, hears, touches, smells, or ingests – continuously communicating back and forth between the brain and the body.

Neurotransmitters play a crucial role in relaying information and maintaining proper health. Here are some critical points about neurotransmitters and their impact:

  • Communication: Neurotransmitters facilitate communication between nerve cells (neurons) in the brain and throughout the nervous system. They transmit signals across synapses, the small gaps between neurons, allowing information to be relayed and processed.
  • Neurological Function: Neurotransmitters regulate various neurological functions, including sensory perception, motor control, cognition, and emotions. They contribute to the overall functioning and coordination of the nervous system.
  • Psychological Function: Imbalances in neurotransmitters can affect psychological well-being and mental health. For example, serotonin regulates mood, sleep, and appetite, while dopamine plays a role in motivation, reward, and pleasure. Imbalances in these neurotransmitters and others can contribute to conditions such as depression, anxiety, bipolar disorder, and schizophrenia.
  • Neurotransmitter Imbalances: When neurotransmitters are not in proper balance, it can lead to neurological or psychological symptoms. For example, low levels of serotonin may be associated with depressive symptoms, while excessive dopamine activity may contribute to psychosis or mania. Imbalances can result from genetic factors, environmental influences, lifestyle choices, and underlying medical conditions.
  • Impact on Physical Health: Neurotransmitters also influence physical health beyond the nervous system. For instance, neurotransmitters such as norepinephrine and acetylcholine play a role in regulating heart rate, blood pressure, digestion, and other autonomic functions.
  • Treatment Approaches: Understanding neurotransmitter imbalances can help guide treatment approaches. Medications targeting specific neurotransmitter systems (e.g., selective serotonin reuptake inhibitors for depression) aim to restore balance and alleviate symptoms. Lifestyle changes, therapy, and other interventions may also be recommended to support optimal neurotransmitter function.

Optimal neurotransmitter balance is required to maintain proper health. Imbalances can cause the brain and the body to be over- or understimulated, producing neurological or psychological symptoms.

Can a Dysregulated Nervous System Impact Health?
Like hormones, neurotransmitters require a delicate balance to keep the body functioning at a peak level.

Genetics, environment, chemicals, and nutritional deficiencies are a few factors that can result in the over- or under-production of neurotransmitters. Once out of balance, the nervous system begins to compensate – which, in time, can lead to neurological or psychological symptoms.

Some more common psychological conditions today are known to be accompanied by neurotransmitter imbalances. However, it's also possible for individuals to present with similar symptoms yet have unique foundational imbalances. Testing helps clarify these root issues.

Neurotransmitters & Symptoms
Do These Symptoms Sound Familiar?
If you regularly suffer from 3 or more of these symptoms, you might have a neurotransmitter imbalance.
  • Aggression,
  • Anxiety,
  • Fatigue,
  • Forgetfulness,
  • Hyperactivity,
  • Impulsive behaviours,
  • Insomnia,
  • Low libido,
  • Mood swings,
  • Obsessive-compulsive disorder (OCD),
  • Panic attacks,
  • Poor concentration,
  • Pre-menstrual dysphoric disorder (PMDD),
  • Severe PMS,
  • Sleeping problems
Neurotransmitters and Children
Neurotransmitter imbalances can also impact children and their overall well-being. Here are some points regarding the effects of neurotransmitter imbalances on children:
  • Behavioural and Emotional Issues: Imbalances in neurotransmitters can contribute to behavioural and emotional issues in children. For example, low levels of serotonin have been associated with anxiety, depression, and mood disorders in children. Imbalances in dopamine may contribute to attention deficit hyperactivity disorder (ADHD) or impulsive behaviour.
  • Learning and Cognitive Difficulties: Neurotransmitter imbalances can affect learning and cognitive function in children. For instance, imbalances in acetylcholine and glutamate may impact memory, attention, and information processing, affecting academic performance and cognitive development.
  • Sleep Disturbances: Disruptions in neurotransmitter balance can lead to sleep disturbances in children. Imbalances in serotonin and melatonin, which regulate sleep-wake cycles, can result in difficulties falling asleep, staying asleep, or experiencing restful sleep.
  • Developmental Disorders: Neurotransmitter imbalances have been implicated in various developmental disorders, such as autism spectrum disorder (ASD). Imbalances in neurotransmitters like serotonin, dopamine, and gamma-aminobutyric acid (GABA) have been associated with ASD symptoms, including social communication difficulties and repetitive behaviours.
  • Sensory Processing Issues: Neurotransmitter imbalances can contribute to sensory processing issues in children. Disruptions in neurotransmitter systems involved in sensory integration, such as serotonin and dopamine, can affect how children process and respond to sensory stimuli, leading to sensory sensitivities or sensory-seeking behaviours.
  • Treatment Considerations: Addressing neurotransmitter imbalances in children often involves a multifaceted approach. Depending on the specific imbalance and symptoms, interventions may include medication, behavioural therapies, dietary changes, and lifestyle modifications. Working with healthcare professionals, such as paediatricians, psychiatrists, or developmental specialists, can help determine appropriate treatment strategies.

It's important to note that children's neurotransmitter imbalances can be influenced by various factors, including genetic predisposition, prenatal and early life experiences, environmental influences, and comorbid conditions. Professional evaluation and individualised treatment planning are crucial for identifying and addressing neurotransmitter imbalances in children.

Neurotransmitters You Should Know
There are many neurotransmitters in the body. The primary messengers are divided into two groups.


  • Dopamine, generally regarded as the brain's pleasure and reward centre, plays the central role in addiction, improves attention, focus and motivation, and modulates movement control.
  • Epinephrine and Norepinephrine regulate the "fight or flight" response, elevate blood pressure and heart rate, stimulate wakefulness and reduce digestive activity.
  • Glutamate functions as the "on" switch in the brain. It's the major excitatory neurotransmitter that decreases sleep, optimises learning, memory, and mood, and improves libido.
  • Histamine plays a role in the body as a neurotransmitter that increases metabolism, promotes wakefulness, and suppresses appetite.
  • PEA (phenylethylamine) promotes energy, elevates mood, regulates attention, and aggression and serves as a biomarker for ADHD.


  • GABA functions as the "off" switch in the brain. It's the major inhibitory neurotransmitter that improves mood, relieves anxiety, and promotes sleep.
  • Glycine plays a dual role as a neurotransmitter and amino acid that serves as a building block to proteins, improves sleep quality, calms aggression, and is an anti-inflammatory agent.
  • Serotonin, generally regarded as the "happiness molecule," contributes to the feeling of calm and well-being that eases depression and anxiety, supports sleep and decreases appetite.
Neurotransmitter Imbalance & Chronic Conditions
Numerous neurotransmitter imbalances may cause persistent health concerns:
  • Anxiety & Depression: Imbalances are often associated with Glutamate (panic attacks), PEA, Histamine, Serotonin, as well as Epinephrine and Norepinephrine.
  • Fatigue: An imbalance between excitatory and inhibitory neurotransmitters is likely.
  • Impulsivity: GABA, Dopamine, and Serotonin are three chemical messengers commonly linked to disorders like ADD, ADHD, and OCD.
  • Insomnia: Glutamate, Histamine, Dopamine, GABA, and Serotonin are chemical messengers often linked to sleep disturbances and insomnia.
  • PMS or PMDD: Imbalances such as Serotonin, Dopamine, Norepinephrine, and GABA are often involved
Neurotransmitter Testing – Giving a Diagnostic Edge in Treating Mood Disorders.

Mental health disorders affect millions of people and profoundly contribute to the burden of disease in society. 

The current treatment paradigm in addressing poor brain health relies on diagnostic tools that encompass the evaluation of clinical signs and symptoms. Despite the lack of testable biomarkers for mood disorders, for many patients, treatments can generally be effective. However, even after treatment, frequent relapse episodes can still occur. Furthermore, a large number of patients suffer from treatment-resistant depression. Therefore, selecting the best therapeutic regimen for each patient remains a challenge and is often discovered through a time-consuming process of trial and error. Also, no single approach works for everyone with any one disorder.

Targeted neurotransmitter testing can help healthcare practitioners achieve a diagnostic edge beyond the traditional psychological inventory by identifying specific imbalances in neurotransmitter levels. Based on neurotransmitter test results, practitioners can identify specific biochemical heterogeneities for each particular patient and objectively monitor therapeutic responses during and after the intervention. Neurotransmitter testing objectively enhances medical assessment and represents a significant advance in the personalisation of the treatment of mood disorders.

How Neurotransmitters Relay Information within the Body

The brain orchestrates the delicate interplay between the body and the mind. Structural brain units, the neurons, discharge neurotransmitters. These neurotransmitters provide a communication platform for the brain to fuel internal systems with information. Anything the body senses, feels, hears, smells, touches, or ingests serves as an input that prompts a swift response. In the central and peripheral nervous system, neurotransmitters operate as chemical messengers that relay signals and receive feedback via electrochemical impulses to regulate cognition, memory, emotions, respiration, heart rate and contractility, digestion, metabolism, blood flow and pressure, and hormonal responses. When released from peripheral organs, neurotransmitters can also behave as hormones by diffusing to distant sites via circulation.

Clinical Utility of Urinary Neurotransmitter Analysis

The aetiology of mood disorders is profoundly complex and likely encompasses many different types of neurotransmitters, how they achieve balance in the brain and the gut axis, and how they each interplay with other hormone systems throughout the body. Appropriate balancing of neurotransmitter signals allows the body to maintain equilibrium. When brain and peripheral neurochemistry become unbalanced, the body will struggle to re-establish physiological integrity, which may present as suboptimal psychological well-being. Excessive or deficient levels of certain neurotransmitters in both the brain and the periphery are associated with a spectrum of neurobiological disorders, such as depression and anxiety. Measuring specific imbalances may be a very effective neurobiological tool in guiding targeted intervention aimed at addressing the individual excess or deficiency in question.

Clinical Validity of Urinary Neurotransmitter Assessment

The importance of effectively assessing and treating mood disorders cannot be overstated. Objectivity is a crucial element of the therapeutic approach to mood disorders. Currently, the standard of care dictates a trial-and-error pharmaceutical approach is taken with each patient based on both self and clinician assessments. However, without information yielded from objective clinical testing, the selection of the most effective treatment for each particular patient with a mood disorder continues to be a challenge. While this may prove effective for some patients, the potential for harm during those interim treatment failures is a genuine concern for clinicians and patients alike. Urinary neurotransmitter testing is performed with the goal that therapeutic interventions may be introduced to address, alleviate, and improve a patient's well-being and have a breadth of data to support the efficacy of the test in clinical practice. Evaluation of neurotransmitter levels in urine provides valuable information about the heterogeneity of patient biochemistry, epigenetics, and how the body functions as a whole. Although the urine test is not a direct measure of brain neurotransmitter levels, it provides relevant information with respect to neurotransmitter regulation in the brain, which can be altered by treatment. The levels in urine often parallel levels in the central nervous system, and the test may, therefore, assist in the selection of patients with mood issues who might respond to specific pharmaceutical or over-the-counter treatment interventions. In other words, the test provides a means to glean a functional systemic perspective regarding each neurotransmitter in the periphery, which ultimately operates under the control of the brain. How do neurotransmitters end up in urine? Some neurotransmitters are produced in the brain and transported across the blood-brain barrier into the blood, and others are produced in the periphery (e.g., norepinephrine and epinephrine). Nephrons, the functional units of the kidney, filter circulating neurotransmitters or their precursors from the blood into the urine. For some neurotransmitters, urinary measurements correlate with levels in the central nervous system (e.g., glutamate, PEA), and for others, what ends up in urine is only reflective of peripheral biosynthesis (e.g., serotonin, GABA, dopamine, norepinephrine, epinephrine). Regardless of production origin, neurotransmitter excretion reflects the overall systemic neurotransmitter tone, the dysregulation of which may contribute to disease states. Identifying abnormality across specific areas of the catecholamine and PEA, GABA/ glutamate, serotonin, histamine, and glycine pathways allows healthcare providers to develop a tailored treatment plan for the specific areas associated with imbalance. 

Toxic & Essential Elements Profile (Thyroid) Symptoms
Thyroid symptoms can manifest in various ways and are often associated with an imbalance in thyroid hormone levels. The thyroid gland plays a crucial role in regulating metabolism, energy production, and the overall functioning of the body. When there is an underactive thyroid (hypothyroidism) or an overactive thyroid (hyperthyroidism), it can lead to a wide range of symptoms. Here are some common symptoms associated with thyroid dysfunction:
  • Weight gain or inability to lose weight even with exercise and diet: Changes in thyroid hormone levels can affect metabolism, leading to unexplained weight gain or difficulty in losing weight despite efforts.
  • Feeling cold all the time when others don't: Hypothyroidism can lower the body's metabolic rate, resulting in a decreased ability to generate and maintain body heat, making individuals feel colder than usual.
  • Low energy and stamina (mostly in the evening): Fatigue and low energy levels are common symptoms of thyroid dysfunction. Individuals may feel tired and lack stamina, particularly in the evenings.
  • Irregular bowel habits – constipation/loose stools: Hypothyroidism can slow down the digestive system, leading to constipation. In some cases, hyperthyroidism can increase bowel movements, resulting in loose stools or diarrhoea.
  • Dry, thinning, and itchy skin: Thyroid imbalances can affect skin health, leading to dryness, thinning, and itchiness. The skin may also become more sensitive to temperature changes.
  • Hair loss: Changes in thyroid hormone levels can disrupt the normal hair growth cycle, resulting in hair loss or thinning of the hair, which can occur on the scalp and other body parts.
  • Insomnia: Sleep disturbances, including difficulty falling asleep or staying asleep, can be associated with thyroid dysfunction.
  • Water retention: Thyroid imbalances can affect fluid regulation in the body, leading to water retention and swelling, particularly in the face, hands, legs, or feet.
  • Menstrual irregularities: Thyroid dysfunction can impact the menstrual cycle, leading to irregular periods, heavier or lighter bleeding, or changes in the duration of the menstrual cycle.
  • Low sex drive: Thyroid imbalances can contribute to a decreased libido or loss of interest in sexual activity.
  • Infertility: Thyroid dysfunction, especially when left untreated, can affect fertility and increase the risk of difficulties in conceiving or maintaining a pregnancy.
  • Memory lapses or slow/fuzzy thinking: Thyroid hormones play a crucial role in brain function. Thyroid imbalances can result in cognitive symptoms such as memory lapses, difficulty concentrating, or feeling mentally foggy.
  • Dry/brittle hair and nails: Thyroid dysfunction can cause dryness and brittleness of the hair and nails, making them more prone to breakage and damage.
  • Depression: Thyroid imbalances can contribute to mood changes and symptoms of depression. Individuals may experience feelings of sadness, low mood, or a loss of interest in activities.
  • Osteoporosis: Untreated or poorly managed thyroid dysfunction, particularly hypothyroidism, can increase the risk of osteoporosis, a condition characterized by weakened and brittle bones.
  • Weight loss: In the case of hyperthyroidism, individuals may experience unexplained weight loss despite maintaining their regular diet.
  • Muscle and joint aches and pains: Thyroid imbalances can lead to muscle weakness, aches, and pains, along with joint stiffness or discomfort.
  • High blood pressure: Hyperthyroidism can raise blood pressure levels, leading to hypertension.
  • Increased cholesterol levels: Hypothyroidism can disrupt the normal metabolism of fats, leading to elevated cholesterol levels and an increased risk of cardiovascular problems.
  • Heat or cold intolerance: Individuals with thyroid dysfunction may have difficulty tolerating extreme temperatures. Hypothyroidism may cause sensitivity to cold, while hyperthyroidism may lead to increased sensitivity to heat.

Thyroid Hormone Imbalance

Thyroid disease or dysfunction can explain a wide variety of symptoms (see list below), yet it is notoriously under-diagnosed. The Colorado Thyroid Disease Prevalence Study published in 20001 found that 9.9% of the study population consisted of people who were not being treated for thyroid problems yet had abnormal thyroid function test results. This suggests that their thyroid disease was previously undiagnosed. This study also found a significantly greater incidence of thyroid dysfunction in women than in men in each decade after the age of 34. The American Thyroid Association estimates that over 12% of the US population will develop thyroid disease during their lifetime and that as many as 60% of people with thyroid disease are not aware of it2. Overt hypothyroidism, with its characteristically high TSH and low circulating T4 levels, and hyperthyroidism, with low TSH and high T4 levels, are easy to recognise clinically. But an elevated TSH associated with normal thyroid hormone (T3 and T4) levels, defined as “subclinical” hypothyroidism, is thought to be present in 4-10% of the general population and in up to 20% of women over 60 years old; and a low TSH with normal T3 and T4 levels, subclinical hyperthyroidism, occurs in about 2% of the population and is most common in women, blacks, and the elderly.

 Elements that Affect Thyroid Function

We are all, to varying degrees, depending on our dietary choices, our supplementation routine, or our lifestyle, exposed to the elements iodine, bromine, selenium, arsenic, and mercury. Levels of these elements in the food we eat are determined by soil levels and other environmental exposure of plants and animals that end up in the food chain and, ultimately, on our own dining tables. We can also be directly exposed to elements through environmental pollution of the air we breathe, as well as exposure through our skin. How does exposure to these elements affect health? Iodine is an essential component of T3 and T4, so its deficiency has a serious impact on thyroid hormone synthesis. While bromine is in the same chemical family as iodine and excessive amounts will compete with iodine in the thyroid. Selenium is a component of the selenoproteins, including the iodothyronine deiodinases, which convert inactive T4 to its active form in the body (T3), and glutathione peroxidase, which prevents free radical damage to the thyroid by destroying the hydrogen peroxide that is a by-product of thyroid hormone synthesis. Arsenic and mercury are toxic heavy metals that form tight complexes with selenium and, therefore, reduce selenium’s bioavailability, resulting in biological effects similar to selenium deficiency, including disruption to thyroid health. While bromine, arsenic, and mercury are known as biological toxins, even iodine and selenium can potentially be toxic if dietary intake, including excessive supplementation, is too high.

Tests in Dried Urine

Urine dried on filter paper strips is a convenient and practical way to test iodine, bromine, selenium, arsenic and mercury to assess deficient, adequate, and toxic intakes. Our Laboratory is a pioneer in commercial testing for elements using a simple, two-point (morning and night) urine collection, into which a filter paper strip is dipped and allowed to dry. Our research has shown the dried urine test to be accurate and comparable to full 24-hour liquid collections, which are cumbersome and inconvenient for patients. To correct results for hydration status, creatinine is also measured, and element test results are expressed in µg/g creatinine.


An essential component of the thyroid hormones T4 and T3. Iodine is an essential nutrient commonly found in dairy products, seafood, iodised salt, and grains. Iodine deficiency compromises thyroid hormone production and leads to serious diseases, including irreversible cretinism, pregnancy complications, goitre, and decreased cognitive function. Iodine deficiency has also been associated with breast cancer. Since over 90% of dietary iodine is eliminated in the urine, the adequacy of recent iodine intake can be accurately assessed with dried urine testing.


A common component of flameproofing agents, fumigants, medications, food products, and pool/spa sanitisers. Bromine has no known function in the body, but high environmental exposure can lead to excess accumulation. If iodine status is low, bromine competes with iodine for tyrosine binding sites within thyroglobulin and thereby impedes thyroid hormone synthesis. Bromine is mostly excreted in the urine, so dried urine analysis can indicate excessive bromine exposure.


An essential dietary element that is incorporated into the selenoproteins in the body, which include glutathione peroxidases, thioredoxin reductases, iodothyronine deiodinases, and the extracellular glycoprotein, selenoprotein P10. These selenoproteins play vital roles in thyroid hormone synthesis, free radical scavenging, DNA synthesis, and cancer prevention11. Foods such as Brazil nuts, seafood, eggs, and grains are significant selenium sources. The optimal therapeutic range for selenium is narrow: excess selenium intake can result in toxicity, while inadequate selenium affects thyroid function because of impaired synthesis and conversion of T4 into the active T312. Urine is the major route of selenium elimination; therefore, dried urinary selenium is an indicator of dietary selenium intake.


An environmental toxin can be found in some foods such as fish, shellfish, seaweed, rice, and fruit. Arsenic is a heavy metal with multiple toxic effects in the body, including carcinogenesis, goitre, diabetes, skin diseases, and damage to the liver, kidney, and cardiovascular, nervous, and endocrine systems. It also competes with selenium, preventing its incorporation into the selenoproteins. This reduces the levels of selenium-containing antioxidants and also the selenoenzymes that are essential for thyroid hormone production, thereby severely compromising thyroid function. Dried Urinary arsenic is a good indicator of recent arsenic exposure since around 80% of dietary arsenic is excreted into urine within three days.


A highly toxic heavy metal can accumulate in body tissues, including the brain. Besides occupational exposure, most human exposure to mercury is through dental amalgams, seafood, and vaccinations. Mercury toxicity can cause nervous system damage, leading to symptoms such as paresthesia, mood changes, and sensory disturbances, while very excessive exposure can also lead to renal toxicity,  respiratory failure and death. Mercury and selenium have a very high affinity for each other and form a thigh complex; as a result, mercury reduces the biological availability of selenium and may inhibit the formation of selenium-dependent enzymes, affecting thyroid function in the same way as selenium deficiency or arsenic exposure. This is particularly problematic in people with inadequate selenium intake and consequent low selenium levels. Selenium can protect against mercury toxicity by sequestering mercury, reducing its bioavailability. There are three forms of mercury in the environment: elemental, found in batteries, thermometers, and dental amalgams; inorganic compounds, primarily mercuric chloride, present in skin-lightening creams; and organic compounds, primarily methylmercury, found in seafood. Elemental mercury is most commonly breathed in as a vapour and absorbed through the lungs, while inorganic and organic compounds are ingested and absorbed through the intestine. The predominant form of mercury in urine is inorganic mercury. The urinary mercury level is an excellent biomarker for whole-body exposure to both elemental and inorganic mercury.


A metabolic by-product that is excreted at a relatively constant rate as long as kidney function is not impaired. It is measured to correct dried urinary element levels for hydration status; the greater the fluid intake, the lower the creatinine level. Iodine, bromine, selenium, arsenic, and mercury results are therefore expressed in µg/g creatinine to allow for urine dilution.


Cadmium is a hazardous heavy metal that is frequently encountered in industrial settings and can also be found in cigarette smoke. Elevated levels of cadmium have been associated with an elevated risk of thyroid disorders, including goiter (enlarged thyroid gland) and thyroid cancer. Due to its toxic nature, minimizing exposure to cadmium is crucial for maintaining thyroid health.


Lithium is a naturally occurring element that is widely used as a medication for certain psychiatric conditions, particularly bipolar disorder. While effective in managing mood disorders, lithium can influence thyroid function by affecting the synthesis and metabolism of thyroid hormones. It is important to closely monitor thyroid function in individuals taking lithium, as it may lead to alterations in thyroid hormone levels and potentially impact overall thyroid health. Regular thyroid evaluations are essential to ensure proper management and minimize any potential adverse effects associated with lithium treatment.

Advantages of Dried Urine for Testing Iodine, Bromine, Selenium, Arsenic, Mercury, Lithium, Cadmium and Creatinine

• Urine collection and shipment of the dried filter strips are simple and convenient for the patient and practitioner.
• Dual collections of urine directly on a filter strip, upon awakening and just before bed, are far more convenient and less subject to the inherent inaccuracies of a 24 h urine collection, yet correlate well with 24 h urine collections.
• Iodine, bromine, selenium, arsenic, mercury, and creatinine in dried urine are exceptionally stable for weeks at room temperature, allowing more flexibility in the collection, shipment, testing, and storage.
• Iodine, bromine, selenium, arsenic, and mercury results expressed in µg/g  creatinine allows normalisation of results when problems exist with urine that is very concentrated or dilutes.

• Iodine testing allows for the determination of iodine status based on CDC and WHO guidelines for thyroid sufficiency, as well as extra-thyroidal sufficiency

Clinical Aspects of Thyroid Dysfunction

Thyroid hormones are primarily involved in directing the metabolic activity of cells, and a properly regulated thyroid is therefore essential to a wide array of biochemical processes in the body. Functional hypo- and hyperthyroidism can also result in symptoms even when hormone levels appear to be normal. Thyroid function can be affected by interactions between thyroid hormones and other hormone systems, particularly estrogens and cortisol, by some nutritional deficiencies, particularly iodine and selenium, and by environmental exposure to bromine, arsenic, selenium,

And mercury. Management of thyroid dysfunction requires an understanding of these interactions and careful monitoring of treatment with thyroid hormone testing. The presence of thyroid peroxidase (TPO) antibodies has been found to help diagnose thyroid disease in patients with abnormal TSH and/or thyroid symptoms with normal thyroid hormone levels and is used to indicate the presence of autoimmune thyroiditis. Hashimoto’s disease is the most common cause of overt hypothyroidism, and 95% of patients are positive for TPO antibodies. Thyroid dysfunction, including thyroid autoimmunity, is also strongly linked with infertility.

Dried Urine – A Convenient Testing Option

The nature of urine collection is non-invasive and preferable over the traditional invasive collection approaches, such as measuring cerebrospinal fluid. Even with liquid urine collection, the patient experiences the enormous hassle of collecting all urine voids over a 24-hour period into a large jug. To circumvent this inconvenience, some labs have settled for collecting only the 2nd void, limiting neurotransmitter results to a single morning time point snapshot. ZRT Laboratory offers an alternative to the liquid urine collection method by offering a simple and convenient collection of four separate urine samples at specific times throughout the day – 1st morning, 2nd morning (approximately 2 hours after the first collection), early evening, and bedtime. Urine is collected onto filter strips by urinating directly on the strip or by dipping the filter card in a cup containing the collected urine. The urine cards are then allowed to dry overnight and sent to ZRT for testing. The convenience of the collection method warrants patient compliance and ease of incorporation into clinical practice.

  • The neurotransmitter test assumes proper kidney function. Neurotransmitter levels are reported in µg/g creatinine, where creatinine is measured from the same sample. This test should not be used in individuals with compromised renal function. 
  • The sample can become very dilute due to increased fluid consumption during the day. Therefore, on the day of testing, individuals should restrict their liquid intake to normal consumption.
  • On the day of testing, individuals are advised to refrain from consuming alcohol, nicotine, bananas, pineapple, and walnuts as they may interfere with testing.