The PERFECT Act of 2026 directs the Secretary of Defense to publish and regularly update a list of dietary supplement ingredients and performance-enhancing substances prohibited for members of the Armed Forces. The list must be made available in multiple formats (full website view, searchable database, downloadable file) and updated at least every 90 days. The bill allows commanding officers discretion not to discipline service members for first-time possession or use of prohibited supplements if the member acted in good faith (e.g., lacked knowledge of the ingredient, purchased from a DoD retail facility, or relied on an outdated list). The bill also requires the Secretary to update the Operation Supplement Safety website with enhanced search functionality and artificial intelligence tools, review opportunities to incorporate dietary supplement safety education into military training, and submit implementation and annual reports to Congress.