This Notice of Funding Opportunity (NOFO) encourages cooperative agreement applications for investigator-initiated, multi-site, clinical trials (Phase III and beyond) to study the effects of natural products (i.e. botanicals, probiotics, and products marketed as dietary supplements) in NCCIH designated areas of high research priority. For this NOFO, natural products include promising nutritional regimens that standardize the amount of a specific naturally occurring nutritional compound (e.g., omega-3 fatty acids, ...