The bill would still need approval from the Senate and governor before it could become law.
LGBTQ+ advocates and health care providers denounced the bill’s passage.
“Representatives today chose to double down on discrimination and block life-saving healthcare that has been studied and proven effective for 40 years,” said Linds Jakows, founder of 603 Equality, an LGBTQ+ advocacy group, in a statement.
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“All Granite Staters should be outraged that loving parents will be charged with felonies for accessing healthcare, a dangerous authoritarian precedent,” Jakows said.
Puberty blockers can pause the onset of puberty and have been used as a part of gender-affirming care for young people experiencing gender dysphoria. The medication stops the body from making sex hormones and its effects are reversible. A young person can still go through normal puberty if they stop taking the blocker.
Hormone therapy typically includes the use of testosterone and estrogen to more closely align someone’s outer appearance with their gender identity.
Republicans who supported the ban argued the treatments are dangerous, and do not have proven long-term benefits. They said people can still access treatment when they turn 18, and they pointed to some individuals whose gender dysphoria is resolved without medical intervention after they undergo puberty.
Speaking in favor of the bill, Representative Erica Layon, a Derry Republican, said gender-affirming care is “turning some of these children into lifelong medical patients, which enriches Big Pharma.”
And she argued that current counseling around gender is inadequate because it is required to affirm the changed gender identity, without sufficiently questioning that change.
Endocrinologists in New Hampshire who provide transgender care said puberty blockers have been used in pediatric endocrinology for decades to treat early puberty, and there is a lot of data demonstrating safety and efficacy. Providers and transgender people said there are many mental health benefits for children who receive gender-affirming care.
Democrats called the ban cruel and discriminatory, since it targets transgender youth accessing the treatment, and includes exceptions for people with ambiguous genitalia.
“If denied this care, trans children will not be able to escape developing secondary sexual characteristics that they’re hoping to avoid,” said Representative Jessica F. LaMontagne, a Dover Democrat. Even if they decide to transition as an adult, she said, they will have to live with those characteristics for the rest of their lives.
“Puberty blockers are temporary and reversible,” she said. “But puberty is not.”
For people assigned male at birth, the medication can slow the growth of facial and body hair, prevent the voice from deepening, and limit the growth of male sexual organs. For people assigned female at birth, it limits or stops breast development, and stops menstruation, according to the Mayo Clinic.
Republicans in New Hampshire remain wary about the risks of such treatments and insist they should be off the table, at least for children.
“Minors deserve protection from experimental medical interventions that could cause lasting harm,” wrote Representative Lisa Mazur, a Goffstown Republican, in the committee’s recommendation to pass the bill.
But civil liberties advocates argued that the government shouldn’t dictate what kind of health care people can access.
“Every Granite Stater deserves the freedom to control their bodies and seek the health care they need free from government intrusion — including LGBTQ+ and transgender young people,” said Courtney Reed, a policy advocate at the ACLU of New Hampshire.
Transgender issues and rights have been among the most contentious issues debated by the Legislature this year, as President Trump has taken executive action limiting passports for transgender people, seeking to exclude them from the military, and to keep transgender girls off girls’ sports teams.
Last week, the New Hampshire House passed a bill rolling back some anti-discrimination protections for transgender people, enabling their exclusion from bathrooms, sports teams, locker rooms, and detention facilities that match their gender identity. On Thursday, the Senate passed its version of a similar proposal, Senate Bill 268.
A similar proposal was vetoed last year by then Governor Chris Sununu. Asked about House Bill 148 on Wednesday, Republican Governor Kelly A. Ayotte said she needs to see the final provisions of the bill before determining her position on it. She did say, however, that she’s made up her mind on women’s sports.
“An issue I’ve felt strongly about is making sure that biological males are not competing in female sports,” she said. “That issue is important to me.”
Proponents of sex-segregated sports team argue it is an issue of fairness and safety.
Last year, New Hampshire passed a bill banning transgender girls from the girls’ sports team in middle and high school. The Senate on Thursday passed Senate Bill 211, a broader sports and locker room ban that would also include college sports.
The new law is facing a lawsuit arguing it unfairly targets transgender girls and violates Title IX and the equal protection clause of the 14th Amendment. The transgender girls who are plaintiffs in the lawsuit against the state are also challenging Trump’s sports ban in federal court.
Amanda Gokee can be reached at amanda.gokee@globe.com. Follow her @amanda_gokee.