What to watch with BDNF and fatigue?

BDNF (Brain-Derived Neurotrophic Factor) is a protein supporting neuron survival and plasticity. Some research links BDNF polymorphisms (e.g., Val66Met) to fatigue, especially post-exercise or in chronic conditions. However, evidence is limited: effect sizes are small, and fatigue is multifactorial (sleep, nutrition, stress, hormones). A consumer DNA test for BDNF alone is not clinically actionable. More reliable markers include ferritin, vitamin D, thyroid function, and inflammatory markers. Be cautious of overhyped genetic claims – they do not replace a thorough medical workup.