"We don't know if there's a real cause or effect. The reason we don't know is because there hasn't been any research on this," said Arizona State Representative Victoria Steele.
One million women seek abortions each year. 25 percent of them use a pill, not a procedure, usually in the first few weeks of pregnancy. A method pro-choice lawmakers consider painless, cheap and relatively easy, but pro-life lawmakers want women to reconsider that choice.
Newly elected Republican Governor Doug Ducey signed the bill on Monday.
"The bill simply says women must be informed that it may be possible to reverse the effects of a medicated abortion if the woman changes her mind," said Arizona State Rep. Kelli Ward.
some doctors believe that can be achieved by giving the woman progesterone, which is commonly used to prevent miscarriages. Opponents say the practice is unproven and irresponsible.
"Basically when you boil it down, I think.. requires medical professionals to commit medical malpractice," said Arizona Rep. Katie Hobbs.
The bill Ducey signed also bans abortion coverage from any Obamacare insurance plans sold in Arizona, joining 23 other states with similar restrictions on taxpayer funds.
"I think it's been made abundantly clear across this nation that the taxpayers should not be paying for abortions," said Arizona State Rep. Steve Smith.
For decades, Congress prohibited tax funds from being used to finance abortions, but Obamacare does not specifically say that, allowing enrollees to use subsidies and tax credits to buy plans that cover abortion services. The Arizona bill closes that so-called loophole.