OBJECTIVES: To examine the efficacy of combination therapy with levothyroxine 
and liothyronine in improvement of general health, psychological problems, and 
metabolic status in primary hypothyroidism.
METHODS: Seventy-one patients diagnosed with primary hypothyroidism were 
randomly allocated into two study groups: the first group received usual dose of 
levothyroxine and the second group received combination of levothyroxine and 
liothyronine for at least 4 months. The main outcomes were psychosocial problems 
(Goldberg's General Health Questionnaire, GHQ-28), bodyweight, heart rate, blood 
pressure, and serum lipid levels.
RESULTS: In both groups serum thyroid-stimulating hormone levels remained 
unchanged compared with baseline. Psychosocial scores, body weight, heart rate, 
blood pressure, and lipid profile in the two groups remained constant. The only 
exception was a small but significant reduction in anxiety/insomnia in combined 
treatment group as compared with monotherapy.
CONCLUSIONS: The data do not support the hypothesis that combined therapy 
improves the well-being and general health of patients.