Puberty blockers given to children who say they were born in the wrong body and want to ‘change gender’ may lower their’ IQs

Powerful ‘puberty blocking’ drugs given to hundreds of young people confused about their gender risk significantly lowering their IQ, a leading scientific expert has warned.

In an alarming study, Sallie Baxendale, professor of clinical neuropsychology at University College London, called for ‘urgent’ research into the impact of the drugs on children’s brain functions.

NHS England stopped routinely prescribing the drugs, which halt physical changes during puberty, last year after a damning study found the treatment could interrupt the process of brain maturation.

But private gender clinics are still giving puberty suppressants to under-16s in Britain – and trans activists insist the drugs are safe.

Now Prof Baxendale has presented evidence on the ‘harmful impact’ of the controversial drugs on the IQ levels of young people.

A study that looked at 25 girls treated with puberty blockers found that their IQ dropped by an average of seven points.

One patient experienced a ‘significant loss’ of 15 points or more, Prof Baxendale said. The girls all suffered from ‘precocious puberty’ leading to the early onset of adulthood.

‘Young people and their families are unable to give truly informed consent to these treatments because their doctors cannot tell them what the long-term effects on their cognitive development will be,’ says Prof Baxendale.

Stephanie Davies-Arai of Transgender Trend, which has campaigned against the prescription of puberty blockers to young people, said: ‘There have never been good long-term studies to prove they are safe.

It is a myth that blockers are ‘reversible’ if given during natural puberty. They prevent a critical period of growth and cognitive development.”