Health Secretary Wes Streeting is being threatened with legal action if he does not ban private sales of less than 18 such as cross-sex hormones such as testosterone.

Advocate for three people – including campaigner Keira Bell – wrote to Streeting that he urges to ban them, as he has done for the children of puberty for children who question their gender identity. .

Ms. Bell says that taking drugs has made her life “upside down”, which has some irreversible effects. The other two people involved are parents and want to remain anonymous.

Cross-sex hormone therapy is used to help people infection in a different penis, in which they were born.

Health Secretary announced in December Indefinite ban on puberty-drug drugs for gender dysforia,

But in a letter sent by Cenclairs Law, Streeting has been told that the law firm will seek a judicial review – a way of challenging the validity of the decision by a public body – until he suits with cross -sex hormones Does not follow

The lawyers stated that private clinics are providing them under 18, despite the fact that they pose at least one as a puberty blockers.

The letter seen by the BBC indicates potential health risks for the developing brains, bones and reproductive systems of children.

Keira Bell has previously taken legal action against NHS – after her treatment when she was a teenager who was the only NHS Ling Clinic at that time.

He was given puberty blockers at 16 o’clock and then male hormone testosterone at the age of 17 before performing surgery to remove her breasts.

28 -year -old Ms. Bell told BBC News: “I was very weak and was dealing with many issues.

“With cross-sex hormones … It not only changes your physical and mental state, but also changes your social condition, especially for women who are taking testosterone. I am one of those people. . “

Hormones can cause irreversible effects, such as the sound is deeper.

He said: “My whole life has turned upside down and there is no way from it.”

Ms. Bell says that she wants to save other youth from going through similar regret.

“Things can feel very important, so it is important for the youth to remember that your whole life is ahead of you.

“Such security needs to be put in law,” she says.

Paul Constream, who is representing lawyer Ms. Bell and two other persons, said: “Given that we know about the dishonest and harmful practices of irregular foreign gender clinics, it is notable that the state secretary has not known Cross is not banned on the leaflet- sex hormones.

“They banned puberty blockers, but failed to ban even more harmful cross-sex hormones that expose children to irreversible lifetime changes.

“This harmful business is disqualified and engraved on the government’s failure to protect unsafe children.”

The Department of Health and Social Care did not directly respond to the threat of judicial review, but said it was working with the regulators that to tighten the rules about the personal provision of cross-sex hormones.

A spokesperson said the landmark Cass review in gender care published last year was not for the ban of cross-sex hormones for people between the ages of 16 to 18.

He said that “additional safety measures” were being placed in NHS, with a group of health professionals now reviewing cases before cross-sex hormones were given to young people.

NHS can write cross-sex hormones for less than 18S.

But the CAS review found that there was a lack of research and “weak evidence” for medical intervention.

As a result, NHS England wrote to all NHS gender clinics, saying that “excessive caution” should be used, which should be done before recommending cross-sex hormones for less than 18.

The way NHS sex services for children are being carried away from medical intervention and focus on comprehensive needs with mental health. Puberty blockers are now used by them – except for clinical trials.

The legal step comes when the courts keep listening to the case of involvement A mother who is trying to stop her 16-year-old, is being given a cross-sex hormone to change her penis,

The case will return to the High Court on Friday.

Between the age of 16 and 18, not an adult legally, a young man is usually seen as being able to make his own medical decisions.