Wyoming is the first American state to pass a stand-alone law that bans abortion pills.
It makes it a crime to prescribe, dispense, distribute, sell or use abortion pills in the state.
Offenders face up to six months jail and a A$13,000 fine.
Women who take the drugs will not be prosecuted and the law does not apply to morning-after pills.
Abortion pills are outlawed in 13 US states under blanket bans on all forms of abortion.
Fifteen other states restrict access to the pills with some requiring a doctor to administer them in person.
Wyoming’s ban on abortion pills is set to take effect in July, pending any legal action that could potentially delay that.
The Associated Press reports a federal judge is due to make a ruling shortly in a case that seeks to overturn the Food and Drug Administration’s approval of over-the-counter and mail-order sales of one of the two abortion drugs.
It could severely restrict nationwide access to mifepristone which is used in around half of all abortions in the US.
Wyoming’s Republican Governor Mark Gordon who signed off on the abortion drugs ban also allowed a separate measure banning nearly all abortions to become law without his signature.
The Life is a Human Right Act has been approved by lawmakers, but has been stalled by a legal challenge.
“I believe this question needs to be decided as soon as possible so that the issue of abortion in Wyoming can be finally resolved, and that is best done with a vote of the people,” Governor Gordon asserted.
Abortion currently remains legal in the state up to viability.
