The Welsh government broke its own law in how it banned puberty blockers for under-18s questioning their gender identity, a Plaid Cymru politician has claimed.

After a review found a lack of evidence of the medicines’ long term impact, NHS GPs in Wales were barred from making new prescriptions, in line with other UK nations.

An expert group says they pose an “unacceptable safety risk”.

But Adam Price and the country’s children’s commissioner, Rocio Cifuentes, said the government should have assessed the impact on children that might have been affected.

The Welsh government said it was committed to developing gender services for young people.

Puberty blockers are licensed to treat early-onset puberty in children – but over the past decade, there has been a significant increase in demand for them to be given to children and young people suffering gender dysphoria.

Last year a review by paediatrician Dr Hilary Cass found a lack of evidence around treatment for under-18s with the drugs.

She said in 2024 there was a lack of evidence they were safe to use to “arrest puberty”, and that it had been unusual to give a “potentially life-changing treatment to young people and not know what happens in adulthood”.

One young trans man, who has begun transitioning as an adult, told BBC Wales he believed puberty blockers could have helped him avoid “the trauma that has come with living in a body that never felt like it was mine”.

The Welsh Conservatives backed the Welsh government position, however.

NHS England announced in March 2024 they would not be routinely prescribed, and in December a ban on private prescriptions was made permanent by the UK government Health Secretary Wes Streeting.

The Commission on Human Medicines (CHM) has also recommended indefinite restrictions, saying there was an “unacceptable safety risk” in the continued prescription.

The drugs are now only available if a patient is a part of a clinical trial, which the UK government has promised, or if a patient was already receiving them.

The Welsh government also introduced regulations last year restricting their prescription by Welsh NHS GPs.

In December former Plaid Cymru leader Adam Price attempted to have the regulations scrapped, raising concerns ministers had not followed a legal obligation to “give due regard” to the UN Nations Convention on the Rights of the Child, enshrined in Welsh law in 2011.

Price, in a Senedd debate, said no impact assessment was written – something the government’s own guidelines says officials should use to ensure ministers follow the law.

Price told BBC Wales: “I think it is clear that the government have acted unlawfully.

“They need to set out with some urgency how they intend to rectify this mistake, and most importantly, engage meaningfully with this group of children and young people whose rights deserve to be respected and whose voices should be heard.”

He argued that children and young people might have been able to raise the absence of a clinical trial.

Asked if he was opposed to the ban, Price said it was not for him “to give a view on a clinical question”.

“The question here is whether the proper legal process was followed, and whether the rights of those children and young people were fully respected, and whether their voices were heard.”

Gwion Williams, 21, began his medical transition in adulthood, having struggled to obtain help via the Welsh NHS when he was under 18.

Mr Williams said he was referred to child and adolescent mental health services, but said it had “dismissed my claims of feeling dysphoric”.

Through his persistence, the service applied for funding to get a referral to the former Tavistock clinic, but because he was 17 and nine months he was disqualified.

“I had to go through the negativity of being told that I was making it all up, just to be told I was right the entire time, and I wasn’t qualifying for the waiting list. So I had to start the procedure all over again to get to the adult clinic.”

He said the Welsh government should have reached out “to both professional and trans views, trans adults and their families and get an understanding of how much it impacts them”.

But without a gender service for young people, Mr Williams said Wales was “severely lacking support for gender queer youth”.

He added: “I think it’s very important for them to assess the situation and realise ultimately there are very, very few GPs prior to this that would have been able or comfortable going through the process of prescribing puberty blockers, because Wales doesn’t have a youth clinic. Most feel they are not qualified to provide any sort of assessment or support.”

In a letter to Welsh children’s minister Dawn Bowden, the children’s commissioner said that without an impact assessment “it is impossible for ministers to evidence compliance” with the 2011 duty.

Ms Cifuentes said the topic related to a small group of children and young people, but said: “These children still deserve to have their rights protected, and it is difficult to see how their individual rights have been considered let alone given due regard through this process.”

She said she “repeatedly” tried to arrange for ministers to meet with young people affected by decisions relating to puberty blockers last year, but the meeting did not take place.

James Evans, Conservative shadow health secretary, said he agreed with the Welsh government’s position.

“Whether they should have consulted with young people or not is up to the Welsh government,” he said.

“If I was the cabinet secretary for health, I would not be giving anything to young people that could harm them in the future,” he added.

“I agree that, yes, the voices of young people are important, but when we are administering something, it needs to be safe and it needs to be checked. As the Cass review said, there is no evidence out there to say that this is safe.”

In the Senedd last month the Welsh government’s chief legal adviser, counsel general Julie James, argued ministers had paid regard to the convention because it was not an outright ban.

She said: “In practice, few, if any, general practitioners in Wales actually prescribe puberty blockers for puberty suppression in children and young people.

“The Royal College of General Practitioners advises that GPs should not prescribe puberty blockers for patients aged under 18 years of age, given the concerns about the evidence base in this area, as well as the specialist expertise required to monitor dosage and side effects.”

She said the Cass review “included a significant programme of engagement, including with young people”. She said the regulations were aligning GP prescribing with the recommendations of the review.

She was criticised by Caerphilly Labour MS Hefin David, who accused James of reading her statement “with no passion, no enthusiasm whatsoever”.

It comes a year after the government admitted it failed to follow its own children’s rights law in a similar case where an impact assessment was not conducted on a decision to scrap holiday help for children who receive free school meals.

Rachel Thomas, head of policy and public affairs for the children’s commissioner, said it felt like “history repeating itself” after the Welsh government failed to conduct an impact assessment on its decision to scrap school holiday support.

She said the government’s commitment to explore a Welsh gender service for young people, made in its LGBTQ+ action plan, also “doesn’t seem to be going anywhere”. Under-18s currently have to be referred across the border, with a clinic available in Bristol.

Following a query by BBC Wales, the commissioner’s office added that she respected the findings of the Cass review.

A Welsh government spokesperson said: “In line with our commitments in the LGBTQ+ Action Plan we are committed to improving gender identity services for young people and adults.

“We are considering the points made by the children’s commissioner and will respond in due course.”