The British government is launching a new effort to reduce its prison population by offering medication aimed at lowering sexual reoffending rates. Justice Secretary Shabana Mahmood announced Thursday, May 22, that 20 prisons across two regions in the United Kingdom will begin administering the treatment, commonly known as chemical castration, to serious sex offenders.
The treatment has been used in the United States since 1996, where several states allow it as a condition for early release or parole.
UK rolling out pilot program to reduce prison population
The pilot program is part of a broader effort to cut reoffending rates and ease pressure on the criminal justice system. It follows an independent sentencing review that called for reforms to address the growing prison population.
According to the report, England and Wales have some of the highest incarceration rates in Western Europe. As of March 2025, data revealed that sexual offenses accounted for 21% of the adult prison population.
Mahmood said studies have shown that chemical castration can cut reoffending among sex offenders by up to 60%. Chemical castration is a medical treatment that uses drugs to lower testosterone levels, which can reduce sexual desire and urges in some offenders. The plan would rely on two types of medication: selective serotonin reuptake inhibitors (SSRIs), which help mitigate intrusive sexual thoughts and anti-androgens, which lower testosterone and curb sexual desire.
“Problematic sexual arousal and preoccupation can be reduced via chemical suppressants and other medications, which can be prescribed for individuals who have committed a sexual offence,” according to the report.
Mahmood said medication won’t be the only focus of the program. It will also include psychological interventions tailored to the needs of individual sex offenders.
A form of treatment familiar to the US
Most recently, Louisiana became the first state in the U.S. to allow a judge to order child molesters to undergo surgical castration. That’s as of August 2024, and anyone convicted of aggravated sex crimes, including rape, molestation and incest involving victims under the age of 13, is included.
In Louisiana, chemical castration is a legal form of punishment for individuals convicted of sex crimes. Similar laws exist in several other states, including California, Florida, Texas, Montana, Oregon, Georgia, Alabama, Iowa and Wisconsin. The practice has been used in the U.S. for decades, often as part of a conditional agreement allowing sex offenders to be released from custody.
Other countries using chemical castration
Zooming out, Korea began using chemical castration on sexual offenders in 2011, marking the first time it was used in Asia.
Denmark and Germany also employ chemical castration, but participation is based on voluntary commitment. In contrast, Poland has made it a mandatory requirement for certain offenders. The Czech Republic stands apart as the only country to have passed a law, in 1966, allowing the surgical removal of sex glands in some sex offenders.
Ukraine and Nigeria also have some form of chemical or sexual castration law.
Mahmood said the program will be voluntary for now, but she is considering expanding it nationwide and possibly making it mandatory for certain offenders.
