Lycopus europaeus (Gypsywort): Effects on the thyroidal parameters and symptoms associated with thyroid function

The aim of the prospective two-armed open study was to examine the effect of Lycopi europaei herba on thyroid function and on associated symptoms during a 3-month follow-up phase. The study population consisted of patients with a basal TSH<1.0 mU/l and hyperthyroidism-associated symptoms.For the first time, the T3/T4 excretion in 24 h urine was measured as a primary objective parameter. As secondary parameters, further hormones, the general condition and the symptoms associated with hyperthyroidism were registered.The urinary T4 excretion was significantly increased in Lycopus europaeus-treated patients (p=0.032). It is supposed that renal mechanisms cause the increased T4 excretion either by a modification within the glomeruli or by impaired reabsorption.Symptoms being specific to the thyroid gland were diminished, as e.g. the increased heart rate in the morning. The Lycopus europaeus preparation showed a good tolerance.These findings confirm positive effects of Lycopus europaeus in slight forms of hyperthyroidism.