The Supreme Court has formally returned the lawsuit to a federal appeals court that has twice allowed the law to stay in effect, rather than to a district judge who sought to block it.
The findings "add to the accumulating evidence that removing restrictions from medication abortion is safe, effective, and improves access," a physician said.
Abortion rights advocates criticized the bill as an attack on a woman s legal right to the procedure, and said the bill would likely shut down some of the state s last operational clinics.
California clinics and their allies in the state legislature on Wednesday revealed a plan to make the state a "sanctuary" for those seeking reproductive care.