Can FT3 help with Schlaf?

FT3 (free triiodothyronine) is the active thyroid hormone. Both deficiency and excess can affect sleep – hyperthyroidism causes restlessness and insomnia, hypothyroidism causes fatigue. However, there is no robust evidence that taking FT3 supplements improves sleep in people with normal thyroid function. On the contrary, unsupervised use can lead to thyrotoxicosis, arrhythmias, and worsened sleep. MyBody-X tests do not measure thyroid hormones; this question is outside the test scope. Anyone with sleep issues should first have a medical evaluation for thyroid disease. Without a medical indication, thyroid hormone supplementation is not recommended and can be dangerous.