A new meta-analysis of clinical trials in Hashimoto’s thyroiditis found that selenium supplements can modestly lower thyroid antibodies and slightly improve thyroid-stimulating hormone (TSH), but the benefits depend a lot on the form, dose, and duration of selenium used.

A 2015 analysis from a large Phase 3 clinical trial found something unexpected. Caffeine on its own did not speed the progression of Parkinson’s disease, but combining caffeine with creatine did.