Alabama has signed into law a bill that requires some convicted paedophiles to undergo chemical castration.
Under the law, those found guilty of a sex offence against a minor under the age of 13 will have to start sex-drive-lowering medication a month before being released on parole.
A court will decide when it is no longer necessary.
Offenders will be required to pay for the medication.
There are now seven states, including Louisiana and Florida, with chemical castration laws.