Is IgG useful for fatigue?

IgG testing for food sensitivities is not a validated tool for diagnosing fatigue. Scientific consensus considers IgG food sensitivity tests pseudoscientific because elevated IgG levels often reflect normal immune exposure to foods, not intolerance or a cause of fatigue. Fatigue is a multifactorial symptom with many potential drivers: poor sleep, stress, nutritional deficiencies (iron, vitamin D, B12), thyroid dysfunction, chronic inflammation, or mental health conditions. An IgG test cannot distinguish these and may lead to unnecessary dietary restrictions without proven benefit. Evidence-based evaluation includes a thorough medical history, blood work (CBC, ferritin, vitamin D, TSH, CRP), and, if food allergy is suspected, controlled elimination-provocation under supervision. Marketing claims linking IgG to fatigue lack robust clinical support. Caveat: self-directed elimination diets based on IgG results risk nutrient deficiencies and may worsen fatigue. Always consult a healthcare professional for persistent tiredness.