MONTGOMERY, Ala. (AP) — Some Alabama sex offenders who abuse young children will have to undergo “chemical castration” while on parole, under a new law, but the requirement has prompted legal concerns and appears to be rarely used in some states that allow it.

The procedure uses medications that block testosterone production in order to decrease sex drive. The Alabama law says sex offenders whose crimes involved children between ages 7 and 13 must receive the medication before being released from prison on parole. Alabama doesn’t allow parole for sex crimes involving children 6 and under.

After Gov. Kay Ivey’s office announced Monday she had signed the bill, some legal groups raised questions.

Randall Marshall, executive director of the American Civil Liberties Union of Alabama, said there are constitutional concerns with forced medication.

Dillon Nettles, a policy analyst with the ACLU of Alabama, said the law harkens back to a “dark time” in history.

“It presents serious issues, involving involuntary medical treatment, informed consent, privacy and cruel and unusual punishment,” Nettles said.

The bill’s sponsor, Republican Rep. Steve Hurst of Munford, scoffs at that kind of talk.

“How in the world can it be any more cruel and inhumane than to molest a child? I want someone to answer that one for me, but they can’t,” Hurst said.

Hurst said he hopes the medication will protect children by stopping abusers from reoffending.

At least seven states have laws authorizing chemical castration in some form.

But its effectiveness can vary.

The hormonal treatment can be useful for a subgroup of offenders whose crimes are driven by sexual attraction to children and want to reduce those urges, said Dr. Frederick Berlin, who treats patients with sexual disorders at Johns Hopkins Hospital and at an independent clinic. However, he has concerns about a blanket criminal justice approach without evaluating the appropriateness in each case.

“Speaking now as a physician, I think it’s absolutely inappropriate to use a medical treatment as a criminal sanction,”  Berlin said.

He said it’s not effective for people whose crimes were driven by drugs, mental illness or other issues.

“These laws tend to go on the books because people understandably are frightened. They want to protect children which I hope every reasonable person wants to do,” Berlin said.

“At its worst, I think the motivation, if we are just going to say it crudely: ‘We are just going to castrate the bastard.’ Or at its best it’s a misunderstanding, and lack of understanding when it would and when it wouldn’t be medically appropriate.”

The stereotypical child molester is male, but a fraction of sex offenders are women. Berlin said the situation is more complicated for women because of hormonal balance involved in the menstrual cycle and maintaining pregnancy, but treatment with a drug like Depo-Provera has been used to help some women gain better sexual self-control.

California was the first state to pass such a law in 1996. Ike Dodson, a spokesman with the California Department of Corrections and Rehabilitation, said it’s is rarely used there. Two parolees are currently receiving treatment. Dodson said one of them is mandated to receive it under law, and the other requested it voluntarily.

Prison officials in Montana and Louisiana told The Associated Press last year that they’re aware of only one case in each state in the last decade in which a judge ordered the treatment. Texas even allows repeat sex offenders to opt for surgical castration. Texas and Florida did not have numbers immediately available on use.

Georgia had a chemical castration statute but repealed it.  Oregon also had a pilot program chemical castration but it was repealed.

The Alabama law says a judge shall order the treatment as a condition of release and will require parolees to receive an initial dose of medication before leaving prison, and to receive additional doses after leaving. A judge would decide when they could stop. They would be billed for the medication, although fees could be waived for those who couldn’t afford it. The law also says an Alabama Health Department employee must administer the medication after an inmate’s release from prison.

Lawmakers say it’s constitutional because it only applies when an inmate seeks release on parole. Inmates who opt to serve their entire sentence would not have to take the medication.

“I think it’s constitutional because it’s not mandatory,” Alabama Senate Judiciary Committee Chairman Cam Ward said. He also said it would apply to a small group of sex offenders.

Hurst began pushing the legislation more than a decade ago after hearing the story of an infant who was sexually abused. He originally proposed permanent surgical castration, but he was told by the state’s then-attorney general that would be found unconstitutional.

The proposal went nowhere in the Statehouse for more than a decade before it won final passage this year on a quick vote in the Senate. Hurst said it may have prevailed because people didn’t notice it.

Hurst said he’s open to improvements in the law, and would like to see a university involved in a future study on effectiveness. But for him, it comes down to simple justice.

“If they are going to mark those children for life, they need to be marked for life. ... My real feelings are that they need to die,” Hurst said.

The law takes effect later this year.