The abortion drug mifepristone, or Mifeprex, entered the U.S. market in 2000. For the past two decades, the drug’s labeling stated some permutation of the following: “Mifeprex … Administration must be under the supervision of a qualified physician,” and “Mifeprex may be administered only in a clinic, medical office, or hospital, by or under the supervision of a physician, able to assess the gestational age of an embryo and to diagnose ectopic pregnancies.”