Clinical Research Directory

Inclusion Criteria: * Adults aged 18 to 65 years. * Diagnosed with single or multiple thyroid nodules confirmed by high-resolution ultrasound, with at least one measurable nodule. * Thyroid nodules meeting one of the following criteria: * ACR TI-RADS category 3 with a maximum nodule diameter ≥ 1.0 cm; or * ACR TI-RADS category 4 or 5 nodules evaluated by fine-needle aspiration and assessed as low-risk papillary thyroid carcinoma, suitable for active surveillance, with patient consent. * Normal thyroid function at baseline, defined as thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) within the reference range. * Traditional Chinese medicine (TCM) syndrome differentiation consistent with liver qi stagnation, blood stasis, or phlegm-dampness syndrome. * Willing and able to provide written informed consent. Exclusion Criteria: * Thyroid nodules confirmed as malignant or follicular neoplasms requiring surgical intervention, or assessed by the investigator as unsuitable for active surveillance. * Presence of hyperthyroidism or hypothyroidism, defined as abnormal TSH, FT3, or FT4 levels. * History of severe cardiovascular, hepatic, renal, hematologic, psychiatric, autoimmune diseases, or other malignancies. * Pregnant or breastfeeding women, or women planning pregnancy during the study period. * Known allergy or hypersensitivity to Xiaojin Pill, Neixiao Luoli Pill, placebo components, or any ingredients of the study medications. * Receipt of thyroid-related surgery, radiofrequency ablation, laser ablation, radioactive iodine therapy, or other treatments that may affect thyroid nodules within 3 months prior to enrollment. * Current use of medications known to affect thyroid function or thyroid nodules, such as amiodarone or lithium. * Poor treatment compliance or inability to complete follow-up as judged by the investigator. * Participation in another clinical trial during the study period.