Critics of the Dutch Protocol have long complained that it was based on flawed research, that clinicians prescribe blockers as a way of pausing puberty when in fact they cause irreversible physical changes, and that data on their long-term effects is at best patchy and at worst shows that they cause more problems than they solve, including reduced bone density.

When the paediatrician Hilary Cass was asked to conduct an independent review of GIDS, she said in an interim report published in 2022 that the “unquestioning affirmative approach” to children who were unsure of their gender overshadowed the need to look into comorbidities, such as poor mental health. 

In other words, children who may be struggling with physical changes to their bodies for all sorts of reasons are being given irreversible medical treatments when in many cases the real cause of their unhappiness may involve autism, depression, ADHD, anxiety or abuse.

Cass also noted that the NHS had applied the Dutch Protocol far more loosely than its authors ever intended. 

She observed that in the Netherlands, children presenting with gender dysphoria are routinely given therapeutic support in advance of – or in some cases instead of – puberty blockers, but “criteria to have accessed therapeutic support prior to starting hormone blocking treatment do not appear to be integral to the current NHS process”.

Moreover, the Dutch Protocol specified that puberty blockers should only be given to children who had expressed “gender incongruence” from early childhood and who were not suffering from significant psychiatric comorbidities.

The NHS diverged from these criteria too. In 2011-2012, there were fewer than 250 referrals to GIDS, most of whom were boys. A decade later, there were more than 5,000 referrals, two thirds of whom were girls who had only started expressing gender-related distress in adolescence.

Rather than withholding puberty blockers from the unexplained explosion of adolescent girls who were claiming to be in the wrong body, as the 1998 Dutch Protocol dictated, GIDS recommended puberty blockers for around 20 per cent of its referrals.

Stella O’Malley, a psychotherapist and the founder of the gender-critical organisation Genspect, says: “The Dutch Protocol became known as international best practice but it is not evidence-based care, it is experimental care, and we can’t even call it an experiment because there isn’t a control group.

“I think there is going to be a very difficult reckoning for all the clinics that followed the Dutch Protocol.”