What to watch with FT4 and Wechseljahre?

During menopause (Wechseljahre), hormonal shifts significantly impact thyroid function. FT4 (free thyroxine) is a key marker of thyroid activity. In perimenopause and menopause, FT4 levels can fluctuate, potentially amplifying or masking symptoms like fatigue, weight gain, mood swings, or hot flashes. Notably, declining estrogen alters thyroid-binding globulin, so FT4 in the low-normal range with normal TSH may still indicate subclinical hypothyroidism. Regular monitoring of TSH, fT3, and fT4 is advisable, especially for women with a family history of thyroid disease or Hashimoto's thyroiditis. Direct-to-consumer (DTC) tests often provide a single FT4 value without clinical context, which is insufficient for reliable assessment. Evidence is based on clinical practice and observational studies; no strong RCT evidence defines specific FT4 targets during menopause. Caution: Do not self-medicate with thyroid hormones; medical evaluation is essential.