FDA is not a physician. It has authority to inform, announce, and apprise—but not to endorse, denounce, or advise. The Doctors have plausibly alleged that FDA’s Posts fell on the wrong side of the line between telling about and telling to. As such, the Doctors can use the APA to assert their ultra vires claims against the Agencies and the Officials. Even tweet-sized doses of personalized medical advice are beyond FDA’s statutory authority. We REVERSE the district court’s judgment of dismissal, and we REMAND for further proceedings.