What role does MC4R play in fatigue?

MC4R (melanocortin-4 receptor) is primarily known for its role in appetite regulation and energy homeostasis. A direct role in fatigue is not well established in the scientific literature. Theoretically, MC4R variants could indirectly influence fatigue through altered energy expenditure or obesity, but this remains speculative. Evidence is limited to animal models and genetic association studies, not clinical fatigue trials. A consumer DNA test for MC4R cannot reliably predict fatigue or energy levels. Clinical fatigue is usually multifactorial (sleep, iron deficiency, thyroid, psychological factors) and not captured by a single gene marker. Be cautious of marketing that overinterprets MC4R as an 'energy gene'.