Unvalidated or misleading laboratory tests

Note: this site is for informational purposes only. To view test results or book a test, use the NHS app in England or contact your GP.

Tests often marketed directly to consumers, typically using blood, urine or other samples, that lack scientific evidence or appropriate clinical validation. It is intended to warn patients and clinicians about tests that may provide unreliable or misleading results, helping people avoid unnecessary expense, anxiety or inappropriate medical decisions.

Formal name 
Unvalidated or misleading laboratory tests 

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

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.

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.

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. 

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.

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

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.