England Expands Chemical Castration Pilot for Sex Offenders
The justice secretary announced that twenty prisons in England will participate in a pilot program involving the chemical castration of sex offenders. this expansion follows a smaller pilot program in south-west England and is based on recommendations from an self-reliant sentencing review.
Did you know? Chemical castration involves the use of drugs to reduce libido and control compulsive sexual thoughts,often combined with psychiatric therapy.
Justice Secretary Shabana Mahmood stated she would extend the initial pilot to two regions, acting on the advice of an independent sentencing review that advocated for its continuation.Ms. Mahmood is also considering a nationwide rollout of voluntary chemical castration for sex offenders, and also the possibility of making it mandatory, though no specific timeline has been established for this decision.
Ethical and Practical Considerations
Forensic psychiatry professor Don Grubin expressed skepticism about the feasibility of mandatory chemical castration. To simply make somebody take [the treatment] would be very unethical and…most doctors I know would be resistant to it,
he said.
Chemical castration involves administering drugs alongside psychiatric treatment,targeting sex offenders with compulsive sexual thoughts or problematic sexual preoccupations. This approach is already in use in some European countries. Germany and Denmark administer chemical suppression voluntarily, while Poland mandates it for certain sex offenders.
independent Sentencing review
The advice to continue the pilot program in England and Wales was one of 48 recommendations from former Lord Chancellor David Gauke’s Independent Sentencing Review. This review was commissioned to address prison overcrowding and explore alternative punishments to custodial sentences.
Ms. Mahmood told the House of Commons that she intends to expand the pilot to gather more evidence and make sure that we are using every tool at our disposal that can cut reoffending.
The specific regions and prisons involved in the expanded pilot have not yet been disclosed.
I’m not squeamish about taking these further measures,
Ms.Mahmood stated. I will make sure that that is what happens.
She also mentioned exploring the possibility of mandating the approach.
Pro Tip: Chemical castration is most effective when combined with psychological interventions that address underlying causes of offending, such as the need for power and control.
It is vital that this approach is taken alongside psychological interventions that target other causes of offending, like asserting power and control,
she added. For some, offending relates to power, but for another subset of offenders, the combination of chemical suppressants and psychological interventions, can, we believe, have a big and positive impact.
Review Findings and Cautions
Mr. Gauke’s report indicated that sexual offenses accounted for 21% of adults serving immediate custodial sentences as of March 2025. The review recommended building a thorough evidence base around the use of chemical suppression for sex offenders and exploring options for continued funding of services in this area.
The review cautioned that these medications should never be used as a risk management tool or standalone rehabilitative offer, and it is only appropriate for a limited number of sex offenders.
It also emphasized the importance of understanding how other jurisdictions have managed the ethical and practical implications,
as gaining valid,informed consent
to treatment is a key tenet of medical law in England and Wales.
Speaking on BBC Breakfast, Mr.Gauke said the review was making cautious recommendations
and that there would be caveats
to the continued scheme. It is not the answer for every sex offender – this is something we would see as a treatment essentially for reducing the risk of reoffending, rather than a punishment,
he clarified. The review recommends exploring how the scheme operates on a voluntary basis rather than mandatory basis, that’s the position of the review.
Expert Opinions and Concerns
Professor Grubin noted that hormonal medications have pretty serious side effects
and somebody would have to really wont to get their sex drive under control to agree to be on those drugs.
However, he suggested it could be a condition of parole, similar to California, where it is mandated for repeat sex offenders whose victims were under 13.
He expressed hope that the extension of the voluntary pilot would proceed, stating, as while we have had clinics running in the prisons for quite a while, we’ve always had difficulty getting it rolled out into the community. If this gives it a push, that would be great.
Josh Babarinde, the Liberal Democrats’ justice spokesperson, emphasized the need for openness, saying the data and evidence (about ongoing voluntary suppression medication pilots) must be made fully clear so that the effectiveness of this intervention can be properly scrutinised.
This move to introduce stricter measures than Mr. Gauke’s recommendation comes as the government faces opposition to accepting most of his other suggestions, including earlier release for some offenders.
How Effective is Chemical Castration?
Chemical castration involves two types of drugs: selective serotonin reuptake inhibitors (SSRIs) to limit invasive sexual thoughts, and anti-androgens to reduce testosterone production and libido. These drugs are administered alongside psychiatric therapy targeting underlying causes of sexual offending, such as the desire for power and control.
These medications have been delivered in some prisons thru the Offender Personality Disorder Pathway, a national program commissioned by the NHS and the HM Prison and Probation Service.The scheme was first piloted in HMP Whatton in 2007 and later expanded to six more prisons in 2016, according to Mr. Gauke’s review. A 2022 pilot extended the program to five prisons in south-west England.
Limited research on the impact of chemical castration has shown important reductions in reoffending rates.One study followed ten offenders, none of whom reoffended after treatment. Another study compared a group of chemically castrated sex offenders with a group who had not been, finding reoffending rates 60% lower among the treated group.
Professor Grubin explained that the intervention is about doctors treating patients, rather than doctors doing a job for criminal justice agencies, but a side effect is that reoffending is likely to be reduced, becuase we know an vital factor in sexual offending and sexual reoffending is sex drive.
He added that the reoffending rate for people on the hormonal medication is very, very low
because it effectively reduces sexual drive.
Though, Professor Grubin noted that demonstrating effectiveness in reoffending studies is challenging due to the time required to observe long-term effects and the ethical difficulties of randomizing high-risk sex offenders into treatment and control groups.
