Myths vs facts: FT3 and Haut

Myth: FT3 levels alone determine skin health. Fact: FT3 (free triiodothyronine) is the active thyroid hormone and does affect skin metabolism, but skin health depends on many factors: T4 conversion, peripheral hormone action, diet, genetics, and environment. An isolated FT3 value without TSH, T4, and clinical symptoms is of limited use. Studies show that both hypothyroidism (dry, scaly skin) and hyperthyroidism (moist, warm skin) alter skin, but the link between FT3 and specific skin conditions like acne or eczema is not strongly established. Many commercial tests overstate FT3's role for skin. Caveat: FT3 assays vary; medical interpretation is essential. Evidence: human-moderate (observational, mechanistic).