Is TSH useful for sleep?

TSH is a screening marker for thyroid function. Both hypothyroidism and hyperthyroidism can affect sleep (e.g., fatigue in hypothyroidism, insomnia in hyperthyroidism). However, TSH alone is not a direct sleep biomarker. The MyBody-X TSH home test is a screening tool only; it cannot diagnose or guide supplement use. A full thyroid panel (fT4, fT3, antibodies) is needed for clinical assessment. Moreover, many other factors (stress, diet, sleep hygiene) influence sleep. The evidence for TSH's usefulness in sleep issues is weak and based on general practice, not specific studies. Caveat: single measurements are unreliable; persistent sleep problems warrant a doctor's visit.