‘Hidden’ study reveals devastating effects of puberty blockers

The NHS’s only specialised gender clinic for children has been accused of hiding bad results about its use of experimental puberty blockers on teenagers.

The Tavistock clinic claimed the effects of the drugs are “reversible” and that the results “have been positive”.

Yet the clinic’s own unpublished study revealed that the treatment actually could have devastating outcomes.

Drug trial

In 2010, Tavistock and Portman NHS Trust’s Gender Identity Development Service (GIDS) launched its trial of puberty blockers for young teenagers with gender dysphoria.

Dr Polly Carmichael, Director of GIDS, claimed in 2014: “Now we’ve done the study and the results thus far have been positive”.

Subsequently the Trust doled out puberty blockers to over a thousand teens – including 230 under the age of 14 – on the basis of the study.

No positive impact

Dr Michael Biggs, an associate professor at Oxford University’s Department of Sociology, said the clinic had failed to open the results of the study to scientists, and that the drugs have not been certified as safe or effective by the manufacturers or by the National Institute for Clinical Excellence.

The study actually showed that after a year of using the drugs there was “a significant increase” in the number of adolescents who said they “deliberately try to hurt or kill themselves”.

Parents also reported “a significant increase in behavioural and emotional problems” and “a significant decrease in physical wellbeing” in girls.

There was no positive impact on “the experience of gender dysphoria”.


Dr Biggs said: “Puberty blockers exacerbated gender dysphoria. Yet the study has been used to justify rolling out this drug regime to several hundred children aged under 16.”

The NHS Health Research Authority revealed that the study itself concluded: “It is not clear what the long-term effects of early suppression may be on bone development, height, sex organ development and body shape and their reversibility if treatment is stopped during pubertal development.”

Dr Carmichael has since admitted: “Nothing is completely reversible.”

It was also revealed that the Tavistock clinic came under great pressure from trans activist groups such as Mermaids, who had opposed the clinic’s initial caution.

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