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Unvalidated or misleading laboratory tests
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This article waslast modified on 11 July 2023.

Below is a review of laboratory tests that are frequently misused and promoted direct to consumers for unvalidated purposes. If you have suggestions to add to this list please send them to us at: Contact Us

For more information about how to check if a laboratory is accredited and operating safely: Laboratory accreditation – the basis for confidence

Please see our article here for more information on how laboratory tests are validated, how they should be used and how results should be interpreted.

Unvalidated or misleading laboratory tests
  • Live blood cell analysis

    Method: A sample of blood is taken and observed under a microscope. Practitioners claim to be able to diagnose a wide variety of conditions by visual inspection of the ‘live’ (or more accurately dying) cells. This technique should not be confused with conventional microscopic analysis by accredited medical laboratories e.g. for blood films.

    Evidence: There is no evidence that this technique is able to reliably diagnose disease. Studies have shown that different practitioners diagnose completely different conditions from the same blood sample and life-threatening conditions, such as leukaemia, are frequently missed during analysis. The advertising standards authority (ASA) has upheld numerous complaints about practitioners of live blood cell analysis who have made unsubstantiated medical claims. The 2013 ASA statement on the topic states: “CAP is yet to see any evidence for the efficacy of this therapy..”

    Comment: Live blood cell practitioners are not regulated professionals and they require no qualifications to be able to offer tests to the general public. The procedure is widely considered to be inaccurate and misleading and it is not offered by any accredited laboratories in the UK. The majority of the conditions that practitioners claim to be able to diagnose can be reliably diagnosed by conventional, evidenced-based techniques available for free through the NHS.

    References and links:

  • Salivary hormone analysis

    Method: A number of websites now offer salivary hormone analysis direct to consumers for the diagnosis of a range of conditions. This usually involves the vendors sending a collection kit in the post so you can collect saliva and post it back to them for analysis. The collection kits and the accompanying instructions for collection vary considerably between vendors. It is often unclear where and how the analysis is being carried out and whether the laboratory doing the analysis is accredited.

    Evidence: There is evidence that salivary cortisol [late-night sample] is a valid and useful test in specific circumstances, such as for the diagnosis of Cushing syndrome or for monitoring patients on hydrocortisone treatment. Analysis of 17-hydroxyprogesterone and androstenedione may also be useful for monitoring the treatment of some conditions of the adrenal gland, such as congenital adrenal hyperplasia (CAH).

    For all other salivary hormone tests, including those for reproductive hormones (testosterone, progesterone, oestrogens), thyroid hormones (TSH, FT4, FT3), additional adrenal hormones (DHEA, aldosterone) and other hormones, such as melatonin, there is little or no evidence that testing is useful. Concentrations of these hormones in saliva fluctuate unpredictably, meaning tests are unable to reliably diagnose disease and results are often misleading. In addition, there is not sufficient evidence that salivary concentrations of cortisol and DHEA are useful in the diagnosis of adrenal gland insufficiency (Addison disease).

    Comment: Even when performed by an accredited laboratory, hormone testing using saliva is unreliable for diagnosing many of the conditions that it is advertised for. In most cases there are simple blood tests available free of charge through NHS providers that can reliably diagnose these conditions and in some cases no tests are required at all.

    Saliva tests may be misleading and when used inappropriately may lead to inappropriate or even harmful treatments. Results of tests should always be interpreted in conjunction with a clinical examination by a qualified medical doctor and saliva tests should never be used in isolation to diagnose or exclude any condition.

    References and links

  • Metabolic profiles and micronutrient analysis (organic acids, amino acids, antioxidant profiles, vitamins, minerals)

    Method
    A variety of metabolic profiles and micronutrient (vitamins, minerals, antioxidants) tests are available through direct-to-consumer websites and alternative practitioners. Often they are advertised as general screens for “metabolic abnormalities” or “nutritional deficiencies”. The actual tests carried out for each profile can vary considerably between retailers. They are often expensive and may cost upwards of £200 per profile.

    These sorts of tests are frequently promoted by alternative practitioners, such as naturopaths and nutritionists, who use results to suggest that patients require supplements or other ‘alternative’ therapies to correct ‘nutritional/energy imbalances’ or micronutrient deficiencies. The types of profiles offered include:

    • Amino acid profile
    • Organic acid profile
    • Micronutrient tests (vitamins and minerals)
    • Essential fatty acid profile
    • Antioxidant profiles

    Evidence
    Many of these tests do have valid clinical uses in specific circumstances, for instance when investigating newborn babies for rare inherited diseases. Tests such as amino acid and organic acid profiles are highly specialised investigations that are used by medical specialists to diagnose and monitor rare conditions. Metabolic profiles like this are only used if a specific medical condition is suspected because a patient has signs or symptoms that would fit that diagnosis. Performing the tests and interpreting results requires highly trained and appropriately qualified staff. Read more about rare metabolic conditions and the screening tests used to detect them here.

    Using amino acid and organic acid profiles for the assessment of nutritional status is not recommended because there is no evidence the tests provide any useful information. Using these tests in this way is likely to be misleading and may lead to an incorrect diagnosis and unnecessary treatment.

    Micronutrient tests look at levels concentrations of vitamins and minerals in the body and are a valid assessment when a patient shows symptoms that suggest deficiency of a particular micronutrient. However, testing is generally only useful for a small number of micronutrients while analysis of others is rarely, if ever, useful. For the majority of micronutrients clinically significant deficiency is unlikely and only occurs in those that are severely malnourished or have specific conditions known to cause deficiency, a good example is Pernicious anaemia and vitamin B12 deficiency.

    Nutrient tests that are frequently useful where risk of deficiency is high or patients show signs or symptoms of deficiency:
    Vitamin B12, folate, vitamin D, iron, calcium, phosphate, magnesium, potassium, zinc

    Nutrient tests that are useful but only in rare circumstances because clinically relevant deficiency is unlikely:
    Selenium, copper, manganese, vitamin A, beta-carotene, vitamin E, some B vitamins (thiamine, pyridoxine), vitamin C.

    Tests where there is very rarely any benefit in analysis:
    Remaining B vitamins (riboflavin, pantothenic acid, niacin), vitamin K, iodine, chromium, manganese, molybdenum, all other trace elements.

    Antioxidant profiles are also frequently offered alongside other micronutrient tests. Antioxidants are a broad range of compounds that play a role in helping the body manage oxidative stress, which is known to be associated with a wide range of diseases. The sorts of compounds that might be analysed include:

    Tocopherols (including vitamin E)
    Carotenes (including vitamin A)
    Coenzyme Q10
    Ascorbic acid (vitamin C)
    Glutathione
    Cystine
    Selenium
    Lipid peroxidases
    Superoxide dismutase (SOD)
    Glutathione peroxidise

    Antioxidant testing is often advertised as a way of assessing the body’s level of ‘oxidative stress’ or ‘antioxidant reserve’. Alternative practitioners frequently use results to suggest dietary modification or supplements to correct antioxidant status or ‘detox’ the body. However, large clinical trials have failed to show that antioxidant supplementation reduces risk of disease in the general population and there is evidence that some antioxidants (e.g. vitamin A, C, E and beta-carotene) may actually be harmful. It therefore follows that testing for antioxidants in this way is not clinically useful and may actually lead to harm. It is also common for patients to be offered a range of expensive but questionable ‘detox’ therapies and health regimes based on results of this testing. For more information see Debunking detox.

    Essential fatty acid testing or fatty acid profiling involves analysing specific types of fats in the blood stream. Commonly advertised are from fatty acids of the Omega-3 and Omega-6 groups. Whilst there is good evidence that modifying diet to include more ‘good’ fats (i.e. omega-3) is beneficial there is no evidence that testing fatty acids is able to provide any further information or health benefit. Alternative practitioners may use results to suggest specific types of fatty acid supplements but there is no evidence that this approach is any better than following standard dietary advice on fat and oily fish intake.

    References

  • The Liver Detoxification Profile

    Method: The tests offered as part of this profile can vary significantly between different vendors. Most commonly it involves the person taking several common drugs e.g. paracetamol, aspirin and caffeine and then measuring their metabolites in blood and urine afterwards. The amount and ratios of metabolites present are an indication of the amount of phase I and phase II metabolism taking place in the liver. Results are sometimes used by alternative practitioners to suggest that the patient has problems that are unrelated to liver function. People may then be recommended to undertake “detoxification” treatment, sometimes at great cost.

    Evidence: There is no evidence that the results of these tests have any clinical utility in patients who are not suffering from advanced liver disease. There is also no evidence that over-the-counter detox regimes have any health benefit regardless of results from tests such as these. Click here for more information from Sense about science on "detox".

    Comment: A vital role of liver is responsible for metabolising a wide variety of unwanted compounds. However, unless the liver is seriously damaged its ability to do this remains unaffected. Genuine liver damage is relatively easy to diagnose using simple clinical examinations, imaging and routine laboratory tests that are available through the NHS

    References and links

  • Intestinal (gut) permeability testing

    Method: The tests offered as part of this profile vary between different vendors. The profile is usually promoted by alternative practitioners to diagnose “leaky gut syndrome”. Testing may involve the patient consuming a drink containing compounds such as mannitol and lactulose before urine or blood samples are taken to check concentrations in the body. Other providers may claim to be able to assess gut permeability by measuring a variety of naturally occurring metabolites in the blood or urine. It is often suggested that abnormal test results mean the gut is "leaky". The patient may then be recommended to exclude large numbers of foods from the diet and to take nutritional supplements to help treat the problem.

    Evidence: "Leaky gut syndrome" is not a recognised medical diagnosis used by Gastroenterologists, doctors who specialise in diseases of the gut (intestine). This article explains in more detail where the term originates and why there is little evidence to support the "leaky gut" theory. Gut permeability testing is not used routinely by regulated health professionals because results are not clinically useful and have be been shown to miss some genuine diseases, such as coeliac disease. 

    Comment: Given that there is no evidence that "leaky gut syndrome" exists as a defined medical condition it follows that tests claiming to diagnose it are unlikely to be of value and are likely to be misleading. Excluding food groups from the diet on the basis of unproven test results may be harmful. 

    References and links: 

  • Digestive stool analysis (or “complete/comprehensive” stool profile)

    Introduction: Stool profiles, often described as “complete digestive stool profiles”, involve testing for a large number of compounds and organisms simultaneously from one sample. Results are often interpreted as suggesting a number of different diseases, some of which may not even be recognised conditions e.g. “leaky gut syndrome” or “gut dysbiosis”. Alternative practitioners may use results of stool profiles to suggest a variety of unproven dietary changes, food supplements and therapies.

    Evidence: Many of the individual tests that are offered do have valid clinical uses but the majority of these are used only by gut specialists (gastroenterologists) in a very selective way when specific diseases are suspected e.g. faecal elastase where pancreatic insufficiency is suspected. Testing for every stool test available at one time makes little sense, is unnecessary and is likely to give misleading results. Some of the tests offered as part of these profiles have no valid clinical use at all, for example; stool cholesterol, short/long chain fatty acids, beta glucoronidase, vegetable fibres, bile acids.

    Comment: Stool tests should be selected by a medical professional (in most cases a Gastroenterologist) based on the history of the patient and their specific gastrointestinal symptoms. For more information on gut health visit: https://www.nhs.uk/live-well/eat-well/digestive-health/

    References:

  • Hair analysis micronutrients/minerals and heavy metals/toxic elements

    Method: Hair analysis usually involves sending a small sample of hair by post or via an alternative practitioner to a laboratory that is often not accredited. The sample may be analysed for minerals, trace elements, vitamins or other compounds, such as toxic metals. Results are often interpreted to suggest the patient is deficient in one or more micronutrients or that they have high levels of toxic elements. They are also frequently used by alternative practitioners to suggest patients need to take expensive supplements to correct “deficiencies” or that they need “detoxification” therapies to remove toxic metals.

    Evidence: A number of studies have investigated the utility of hair analysis for the diagnosis of nutritional deficiencies, all with the same conclusion – hair analysis is not reliable for evaluating the nutritional status of individuals and frequently gives misleading results.

    There are a large number of factors that affect levels of minerals and trace elements in hair making accurate and useful interpretation almost impossible. Analytical techniques have been shown to be unreliable and a lack of appropriate control material makes quality assurance particularly difficult. This explains why controlled studies have shown highly variable results when the same hair sample is sent to different laboratories.

    When performed correctly with strict collection procedures hair analysis for toxic elements (metals) may be useful in some limited circumstances e.g. forensic purposes or toxicological studies. However, there is no evidence it is useful for screening patients with non-specific symptoms that are not typical of toxicity. It should be noted that toxicity is extremely uncommon where no specific environmental exposure is known to have occurred.

    Comment: Hair mineral analysis should not be used for the diagnosis of nutritional deficiency and it is very rarely useful for diagnosing heavy metal toxicity. Results are frequently misleading and should never be used to make a diagnosis without consultation with an appropriately trained and regulated medical professional. Even when measured accurately hair mineral and trace element levels are poorly correlated with true body status and validated methods of nutritional assessment.

    References 

  • The AMAS test for cancer

    Method: AMAS stands for Anti-malignin antibody in serum (AMAS) and it is a blood test offered by only one laboratory in the USA. It is often advertised by online retailers as a simple blood test to detect early cancer and monitor treatment or that the test may help doctors learn more about a patient’s prognosis.

    Evidence: There is little published evidence from independent sources to support the claims made for the AMAS test. Despite more than 20 years of availability, the test is not accepted by most in the medical community because of a lack of evidence that it is reliable. The few studies that have been carried out have not shown it to be of any benefit over conventional diagnostic methods. Commercial companies may state the test has been approved by the FDA (US Food and drug administration) but there is no evidence to suggest this is true.

    Comment: The AMAS test should never be used alone to diagnose cancer or to screen asymptomatic people for cancer because results could be misleading. The available evidence indicates that a negative AMAS test should never be interpreted as an "all-clear" message if there is any other reason to suspect the possibility of cancer.

  • Cytotoxic testing for allergy (Lymphocyte sensitivity test, ALCAT test, FACT test)

    Method: Cytotoxic tests for allergy and food intolerance are not new and have been available in various guises since the 1970’s. The test involves isolating a patient’s white blood cells (Leucocytes) and incubating them with dried food extracts or other potential allergens on a microscope slide. Changes in the appearance, movement or size of cells are interpreted as suggesting “sensitivity” or “allergy” to that particular food stuff or allergen. The ALCAT test and other more modern variations of the test involve more automated analysis using a device such as a cell counter, but the principle remains the same.

    Evidence: As early as 1980 professionals were publishing position statements stating that cytotoxic testing is of no clinical benefit. Practitioners offering the test have been shown to give completely different results after analysing the same sample and have diagnosed allergy in patients where no such condition exists. Test results do not appear to correlate with established diagnostic tests for allergy, such as skin prick testing or specific IgE analysis.

    Comment: Even modern variations of the cytotoxic test are not able to reliably diagnose allergy and frequently produce misleading results.

    References

  • Food intolerance/sensitivity testing (food specific IgG, IgG4)

    Method: When offered commercially, food “intolerance” or “sensitivity” testing most frequently involves testing a blood sample for specific types of immunoglobulins called food-specific IgG antibodies. These food intolerance “screens” may test for food-specific IgG to 100+ different food stuffs and frequently cost upwards of £200. Results are often interpreted to suggest that removing a range of foods from the consumer’s diet will be beneficial to their health. IgG based intolerance tests should not be confused with IgE based allergy tests that do have proven clinical benefit in the diagnosis of allergy.

    Evidence: IgG antibodies to foods are commonly detectable in healthy adult patients and children who have no symptoms of food allergy whatsoever. There is no credible evidence that these antibodies cause any clinical symptoms and it therefore follows that measuring them is of no use for diagnosing food allergy or intolerance. A number of professional associations have issued statements recommending against the use of food-specific IgG testing (see references). The National Institute for Health and Care Excellence (NICE) also now specifically recommends against IgG testing for the diagnosis of allergy because results are frequently misleading and may lead to potentially harmful dietary changes, particularly in children.

    Comment: There is no evidence that food-specific IgG antibodies are responsible for food intolerance, allergy or any other clinical condition. Results are frequently misleading and the test is specifically recommended against by NICE and other professional bodies. Restricting diet based on food-specific IgG results may result in serious nutritional deficiencies, particularly in children.

    References:

  • Allergy testing using allergen-specific IgE (RAST test)

    Method: IgE testing in allergy has a well established and clinically validated role in the diagnosis of some allergies. For more detail see this Lab Tests Online-UK article. However, the test is now widely available direct to consumers via alternative practitioners and internet retailers, many of whom are using the test inappropriately and providing misleading interpretations of results.

    Evidence: Inappropriate use of IgE testing may be divided into three areas:

    (1) Inappropriate patient selection: As with any diagnostic test, using an IgE test in patients where there is no clinical evidence of allergy increases the likelihood of irrelevant false positive results. For example, testing for food allergy in patients with only symptoms of pollen allergy may lead to positive results that are not clinical significant. This can then lead to inappropriate and unnecessary dietary restrictions.

    (2) Misinterpretation of results. Elevated levels of allergen-specific IgE are found in some healthy individuals without clinical allergy. This has been demonstrated in studies where patients who have positive food-specific IgE are ‘challenged’ with specific foods to assess allergic response (a ‘gold standard’ test for allergy). In the absence of a history of clinical allergy, positive allergen-specific IgE results are usually of little diagnostic significance.

    (3) Inappropriate data presentation. Presentation of specific IgE results as raw numerical values has no scientific or clinical rationale, has not been shown to correlate with clinical reactivity and makes misinterpretation more likely.

    References:

  • Unvalidated Candida tests

    Background: In recent decades many symptoms and conditions have been linked with overgrowth of Candida albicans (yeast) in the gut (often termed “Candidiasis hypersensitivity syndrome”). The theory suggests that release of fungal toxins results in a variety of symptoms including fatigue, arthritis, irritable bowel, food intolerance as well as psychological symptoms. Proponents of the theory suggest that these toxins weaken the immune system, predisposing to further symptoms from ingested foods and toxins. Patients diagnosed with the ‘condition’ are frequently offered treatments, such as dietary supplements and antifungal drugs, some of which have potentially serious side effects. 

    Method: A variety of tests have been devised to diagnose Candida overgrowth, including blood tests for Candida antibodies (IgG, IgA or IgM), urine tests for markers of Candida metabolism (e.g. D-Arabinitol) or stool tests to look for yeast cells directly in faeces.

    Evidence: Candida is a normal gut organism occurring in healthy and unwell patients alike. The immune system will produce antibodies to Candida as part of normal immune function and so the presence of these antibodies in blood is of little significance. Demonstrating the presence of Candida in stool samples is entirely likely in healthy patients with a normally functioning gut and immune system.

    In any case, controlled studies have shown there is no evidence of excessive growth of Candida or altered immune responses to this organism in patients suspected of having this syndrome. There have even been clinical trials that treated patients who reportedly have the ‘condition’ with antifungal therapy but this made no difference to their symptoms. There is neither a scientific rationale nor published evidence that elimination of Candida with diets or anti-fungal therapy is of clinical benefit in these individuals. 

    Summary: There is little evidence to suggest a condition such as Candidasis hypersensitivity syndrome exists. Commercially available tests for Candida are likely to give positive results in perfectly healthy individuals, which may lead to inappropriate, expensive and potentially harmful treatments.

    References:

  • Unvalidated tests for Lyme disease

    Background: The NHS website provides a comprehensive background on Lyme disease and Lab Tests Online-UK provide a comprehensive article on validated methods of testing for Lyme disease.

    Method: Validated methods of diagnosis involve using a combination of ELISA for B. burgdorferi antibodies, western blot analysis and/or PCR for B. burgdorferi DNA. However, there are now a variety of unproven tests and testing strategies offered directly to the consumer that are claimed to be accurate methods of diagnosing Lyme disease. These include;

    • Capture assays for antigens in urine
    • Culture, immunofluorescence staining, or cell sorting of cell wall-deficient or cystic forms of B. burgdorferi
    • Lymphocyte transformation tests
    • Quantitative CD57 lymphocyte assays
    • “Reverse Western blots”
    • Alternative ‘in-house’ criteria for interpretation of immunoblots
    • Measurements of antibodies in joint fluid (synovial fluid)

    Evidence: There are specific recommendations from Public Health England and the Centre for Disease and Prevention (CDC) on how to test for Lyme disease appropriately. It is important this procedure is followed because even the validated tests available can give incorrect results that require confirmation. This is particularly true of the first-line ELISA test, which is good at picking up genuine cases but can also can give false positive results in patients without Lyme disease. Initial tests therefore need confirmation via another method, such as Western blot.

    The above additional tests that are frequently seen advertised directly to consumers are not validated for the diagnosis of Lyme are likely to give misleading results, most often false-positives where no Lyme disease is present.

    It is very important that testing is carried out only when a patient exhibits specific symptoms of Lyme disease. If testing is carried out in patients with low risk of genuine infection the chance of test results being misleading increases significantly. Tests should therefore only be requested where a qualified clinician has taken a detailed history from the patient and assessed their clinical symptoms.

    Summary: The accurate diagnosis of Lyme disease requires thorough clinical examination by a qualified clinician and, if appropriate, testing using the recommended diagnostic procedure. Unvalidated tests are frequently offered directly to consumers via online retailers or unqualified alternative practitioners and results are often misleading, which can lead to inappropriate, expensive and sometimes harmful treatments.

    References:

  • Gender prediction test

    Method: Various urine tests have appeared on online in recent years that claim to be able to predict the gender of an unborn baby. These test kits have not been validated in any way, shape or form and do not appear to have undergone any scientific evaluation. It is not at all clear what these test kits are actually measuring.

    Evidence: No evidence. These tests appear to be “random number generators” with an equal diagnostic performance likely to be obtained from tossing a coin. Small print accompanying the test description may suggest it is for “entertainment purposes only”, although this is far from clear from the associated advertising (ASA adjudication).

    Comment: If parents wish to know the sex of their unborn child this maybe possible at the 20 week ultrasound scan.

    References:

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