Is IgG Unverträglichkeitstest useful for fatigue?

IgG food intolerance tests are often marketed for fatigue, but scientific evidence is weak. IgG antibodies to foods typically reflect normal immune exposure, not true intolerance. Studies show no consistent benefit for fatigue; most positive effects are due to placebo or elimination diets. MyBody-X does not offer such tests; the provided contexts (DNA tests, hormone panels) are not applicable. For persistent fatigue, medical causes like iron deficiency, thyroid disorders, or sleep apnea should be evaluated by a physician. An IgG test can be misleading and lead to unnecessary dietary restrictions. Evidence: marketing/unclear. Caveat: Do not self-diagnose or change diet without medical supervision.