Abstract:Objective To investigate the short- and long-term efficacy and safety of Modified Buzhong Yiqi Decoction in the treatment of subclinical hypothyroidism. Methods A total of 120 patients with subclinical hypothyroidism were randomly divided into treatment group and control group, with 60 patients in each group. The patients in the treatment group were given Modified Buzhong Yiqi Decoction, and those in the control group were given Euthyrox. The course of treatment was 3 months for both groups. Both groups were followed up for 12 months and were compared in terms of thyroid function and symptom score before and after treatment, as well as the change in thyroid function during follow-up. Results A total of 12 patients in the control group and 6 in the treatment group were lost. Both groups had a significant reduction in thyroid-stimulating hormone (TSH) at each time point after treatment (P<0.05). During follow-up, the treatment group had a serum level of TSH maintained below 4 μIU/mL at each time point and had a significantly lower level than the control group (P<0.05). The treatment group had significant reductions in the scores of weakness, fear of cold, oppression in the neck, swelling in the hands and feet, abdominal distension, and goiter and the total symptom score after treatment (P<0.05); the control group had significant reductions in the scores of weakness, oppression in the neck, abdominal distension, and goiter and the total symptom score after treatment (P<0.05), while there were no significant changes in the scores of fear of cold and swelling in the hands and feet (P>0.05). There were significant differences between the two groups with respect to the changes in the score of each symptom and the total symptom score after treatment (P<0.05). After the 12-month follow-up, the treatment group had significantly better prognosis than the control group (P<0.05). There were no significant adverse reactions in either group. Conclusion Modified Buzhong Yiqi Decoction has good short- and long-term efficacy and safety in the treatment of subclinical hypothyroidism.