Myths vs facts: FT4 and Abnehmen

FT4 (free thyroxine) is a thyroid hormone often linked to weight regulation. A common myth is that low FT4 inevitably causes weight gain – in reality, the relationship is complex: while overt hypothyroidism reduces basal metabolic rate and can promote weight gain, individuals with FT4 in the lower normal range often show no significant weight difference compared to those with higher values. Another myth is that taking thyroid hormones (e.g., levothyroxine) aids weight loss – this is dangerous and not indicated, as overdosing can lead to thyrotoxicosis with palpitations, muscle wasting, and osteoporosis. The fact is: FT4 alone is not a reliable marker for metabolism or weight loss success. Thyroid function should always be assessed together with TSH, T3, and clinical symptoms. For sustainable weight loss, calorie balance, physical activity, and individual genetic factors are key. Direct evidence for FT4 as a sole predictor of weight loss is lacking; the evidence base is moderate, relying on associations rather than causation. Caution: self-medication with thyroid hormones can cause serious health harm.