Thyroid nodules present a variable risk of malignancy depending on the cytological result obtained from the ultrasound-assisted thyroid fine needle aspiration biopsy. According to the Italian Cytology classification SIAPEC-IAP 2014, the TIR3A nodules are indeterminate nodules with a risk of malignancy lower than 10%. Clinical and instrumental follow-up is recommended in these cases, including repetition of the fine needle aspiration. A study have demonstrate the effect of a six-month treatment with a supplement containing myo-inositol and selenium on the size and elasticity of benign thyroid nodules. Our hypothesis is that the use of this supplement can determine a reduction in the size and consistency of the nodule assessed through ultrasound and elastosonography also in cytologically indeterminate (TIR3A) nodules and that treatment can reduce the cellular proliferation of these nodules assessed by immunocytochemistry. Therefore, we design a prospective randomized pilot study to assess efficacy and safety of myo-inositol and selenium in TIR3a thyroid nosules, comparing treated and untreated patients.