After treatment of hyperthyroidism, a significant decrease in FT3 from 10.2 ± 5.4 pg/mL to 3.2 ± 1.0 pg/mL (p < 0.000001) and FT4 concentrations from 4.03 ± 2.33 ng/mL to 1.10 ± 0.82 ng/mL, respectively (p < 0.006), was accompanied by a marked decrease of serum sclerostin levels from 43.7 ± 29.2 to 28.1 ± 18.4 pmol/L (p = 0.000001). Here, SOST is linked to hyperthyroidism.