WATCH LIVE: Senators question Heidi Overton in confirmation hearing for FDA commissioner

Dr. Heidi Overton appeared before the Senate Health, Education, Labor, and Pensions committee to begin her confirmation hearing for the role of Food and Drug Administration commissioner. President Donald Trump nominated her in August, praising her as a "ROCKSTAR in my Administration." Overton is set to lead the FDA after Marty Makary stepped down amid conflicts with lawmakers, pharmaceutical companies, and Trump over vaping regulations.

If confirmed, she will replace acting commissioner Kyle Diamantas, who has been in the position since May 2026. The hearing's chair, Sen. Bill Cassidy, questioned Overton about the safety and efficacy of childhood vaccines and the abortion drug mifepristone, with Overton confirming their safety and effectiveness according to FDA standards.

Cassidy pushed for her to directly address any disagreements with the president on vaccine safety, but she avoided giving a direct answer. Cassidy also raised concerns over her past comments on mifepristone, accusing her of denying scientific facts and attacking abortion rights. Overton, a physician with a doctorate from Johns Hopkins University, has been described as a loyal supporter of Trump, particularly in his efforts to revise the childhood vaccination schedule.

Two sources familiar with the nomination told ABC News that her loyalty to the president was a key factor in her nomination. Critics, including Sen. Patty Murray, have expressed concerns over her nomination, accusing her of publicly denying scientific facts and undermining abortion access and women's health.