Is FT4 useful for Haut?

FT4 (free thyroxine) is a thyroid hormone that regulates metabolism. An imbalance can cause skin issues such as dryness, itching, or excessive sweating – especially in hypo- or hyperthyroidism. However, FT4 is not a specific marker for skin health. Evidence comes from observational studies and clinical experience, not from randomized controlled trials focused solely on skin. FT4 testing is useful when thyroid dysfunction is suspected, not as a standalone skin test. In consumer lab tests (e.g., from DNA or metabolism tests), caution is needed: single values without clinical context can be misleading. Skin is influenced by many factors – hormones, diet, microbiome, environment. FT4 alone is insufficient to assess skin conditions. Consult a dermatologist or endocrinologist for skin concerns.