Tests Sold in Integrative Practice: Evidence-Based Testing vs Broad Panels, Food IgG, Hair Mineral, "Adrenal" and Microbiome Tests

The short version

Some tests sold in naturopathic, integrative and functional medicine settings are well-established tests used for a different purpose than the one marketed. Others have been studied and found unreliable. The table below keeps the question, the finding and the strength of evidence together. Evidence labels: established, mixed, insufficient evidence, no good evidence of benefit, marketing claim.

Evidence-based testing vs broad screening panels

A test is useful when the result changes what a clinician does and the test has been shown to measure what it claims. Tests ordered because of specific symptoms, an examination or a known risk (for example a morning cortisol level when a doctor suspects adrenal insufficiency) are different from a long panel offered to anyone who feels "off." Broad panels raise the chance of results that are borderline, mislabeled or unrelated to symptoms, which can lead to more tests, more supplements and more worry. You are entitled to ask any practitioner: what condition is this test looking for, what will I do differently with each possible result, and is this test recommended by a medical society for that purpose?

Food IgG testing claims

What it is. A blood test measuring IgG antibodies to a list of foods, sold to find "food sensitivities."

Legitimate medical use. True food allergy is an immune reaction, and testing for it is done with a clinician, using methods such as skin tests, matched to your symptoms. [5] Food intolerance is a separate problem of digesting a food. The NHS describes diagnosis by a trial elimination diet then reintroduction, with blood tests or a breath test in some cases. [6]

What the evidence shows for the marketed use. The Canadian Society of Allergy and Clinical Immunology says there is no body of research supporting food-specific IgG testing to diagnose or predict reactions to food, and that IgG to a food is a marker of exposure and tolerance, so positive results are expected. [1] It also warns that a person with a true IgE-mediated allergy may not have raised IgG and could be wrongly told to reintroduce the food. [1] The NHS says home tests sold to diagnose food intolerance are not recommended and may suggest avoiding many foods, which can be harmful. [6]

Risk. Needless restriction of foods, missed true allergy, cost. See also Wellness: leaky gut cleanses and gut tests.

Hair mineral analysis

What it is. Lab measurement of minerals in a hair sample, marketed to assess nutrition or toxic exposure.

What the evidence shows. A JAMA study sent split hair samples from one healthy volunteer to six commercial US laboratories. Differences between highest and lowest reported concentrations exceeded 10-fold for 12 minerals, and the labs' normal ranges gave conflicting high, normal or low classifications for nearly all minerals. [2] The labs also gave conflicting supplement recommendations. [2] The authors recommended that practitioners not use such analyses to assess individual nutritional status or suspected exposures. [2] This is a 2001 study; we did not find a newer comparison.

Instead. If poisoning or a deficiency is suspected, ask a doctor which blood or urine test fits the concern.

"Adrenal fatigue" testing

What it is. Saliva or blood cortisol tests used to label tiredness as "adrenal fatigue."

Legitimate medical use. Real adrenal insufficiency is a recognized, rare condition of cortisol deficiency. A JAMA review says symptoms such as fatigue, nausea and weight loss are nonspecific, and diagnosis uses early-morning blood measurements of cortisol, corticotropin and DHEAS, sometimes followed by a stimulation test. [7] It also says glucocorticoid medicines are a common cause. [7]

What the evidence shows for the marketed use. A 2016 systematic review of 58 studies reported mostly conflicting results across the cortisol methods used, and noted that "adrenal fatigue" has not been recognized by any endocrinology society. [3] Ongoing fatigue needs a proper look for common causes. See cortisol and adrenal fatigue and the adaptogen claim check.

Commercial microbiome tests

What they are. Stool sequencing kits that report bacteria and often recommend diets or supplements.

What the evidence shows. A 2025 review notes many companies offer microbiota analysis of dubious quality, sometimes as a way to sell supplements. [4] Proper evidence not found for a consumer kit that reliably guides treatment: we looked for current guidelines and did not find one. Stool tests ordered by a clinician for a specific problem, such as suspected infection, are a different matter.

Before you pay for a panel

• Ask what the test is validated to detect.
• Ask what a normal and abnormal result would change.
• Keep your own doctor informed, and see red flags in health claims.