It is becoming harder and harder to assess claims that transgender medicine is based upon rock-solid evidence. Much of the time, the debate is carried on in columns of newspapers, not medical journals.

The latest skirmish in America’s Trans Wars was found in the letters page of the Wall Street Journal. On July 4, the president of the Endocrine Society, Stephen R. Hammes, published an indignant refutation of “misinformation” about trans medicine. “More than 2,000 studies published since 1975 form a clear picture,” he wrote. “Gender-affirming care improves the well-being of transgender and gender-diverse people and reduces the risk of suicide.”

A few days later 21 physicians from 9 countries published a rebuttal of these claims. In Europe, medical associations and national health departments are increasingly sceptical of the value of gender-affirming medicine. They claimed that Dr Hammes’s complacent view was “not supported by the best available evidence”.

Every systematic review of evidence to date, including one published in the Journal of the Endocrine Society, has found the evidence for mental-health benefits of hormonal interventions for minors to be of low or very low certainty. By contrast, the risks are significant and include sterility, lifelong dependence on medication and the anguish of regret. For this reason, more and more European countries and international professional organizations now recommend psychotherapy rather than hormones and surgeries as the first line of treatment for gender-dysphoric youth.

Dr. Hammes’s claim that gender transition reduces suicides is contradicted by every systematic review, including the review published by the Endocrine Society, which states, “We could not draw any conclusions about death by suicide.” There is no reliable evidence to suggest that hormonal transition is an effective suicide-prevention measure.

The politicization of transgender healthcare in the U.S. is unfortunate. The way to combat it is for medical societies to align their recommendations with the best available evidence—rather than exaggerating the benefits and minimizing the risks.