Cole said she had a double mastectomy at age 15 and urged the committee to adopt the proposal.
"All of the talk about mental health, self-perception, pronouns and ideology leads me to this question: Why is the mental health epidemic not being addressed with mental health treatment, to get at the root causes for why female adolescents like me want to reject their bodies?" Cole said.
But Mary Flynn, a consulting psychologist whose 12-year-old daughter is transgender, defended gender-affirming care for children, when appropriate.
"It's a joy to raise this beautiful child, and everything we've heard before is nothing that I've ever heard before in any support group, by any physician, by anything," Flynn said. "If we did not have this medicine, she would not be alive. ... What you're talking about is waiting until age 18. Well, they won't be here. This group commits suicide."
LGBTQ advocates said the rule, if given final approval, would be challenged in court.
"Unquestionably there will be legal challenges," attorney Simone Chriss, director of the Trans Rights Initiative at the Southern Legal Counsel organization, said during a news conference organized by the advocacy group Equality Florida.
Sujatha Prabhakaran, a Sarasota doctor who treats transgender patients, called the proposal "medically unsafe and cruel." She said she is unaware of any clinical studies, such as those outlined in the proposal, ongoing in the state.
"I'm not surprised actually but, as far as I can see right now, there are no trials here in Florida and I think that just points to, again, the stigma and discrimination that trans people face here in Florida," she said.
Six experts invited to participate in Friday's meeting had opposing views on gender-affirming treatment, with critics pointing to a lack of "high-quality evidence" to support it. Proponents, meanwhile, argued that years of studies and practice show the treatment to be safe and effective and that denial of treatment can be dangerous.
Treatment opponents contended that gender dysphoria is a mental health issue that should be treated with psychological care.
"We're talking about are there any randomized control studies" that compare groups of patients who received hormone therapy or puberty blockers to those who receive mental health treatment, said Michael Laidlaw, a California-based endocrinologist. "We don't have high-quality evidence, based on that."
But Yale School of Medicine professor Meredithe McNamara disputed Laidlaw's conclusions.
"To state the matter firmly and positively, gender-affirming care for gender dysphoria does meet generally accepted medical standards. It is not experimental or investigational. Gender-affirming care is supported by every major medical organization," McNamara, who specializes in adolescent medicine, said, adding, "this consensus is based on a solid body of evidence" of more than 16 studies.
The panel ran out of time before agreeing on how to require "informed consent" from parents and children who already are receiving hormone therapy or puberty blockers.
"We recognize there may be actually some harm to stop," David Diamond, a Winter Park oncologist who chairs the Board of Medicine, said. "These folks are undergoing treatment. ... The intent is simply to say the rule allows you to continue, but please understand that you need to be aware of these complexities."
Ed Tellechea, a longtime lawyer for the medical boards, noted the state has informed-consent requirements for medical marijuana treatment and cataract surgery.
"When we did those informed consent, we drafted these forms in multiple meetings, and we're not getting that right now. We're getting the broad outlines of what you want to see," he said.
Throughout Friday's meeting, Florida Board of Medicine member Zachariah Zachariah, who chaired the committee, cautioned members of the audience who broke out in cheers or jeers.
For example, LGBTQ advocates erupted after Zachariah announced that public testimony had ended and refused to allow state Rep. Anna Eskamani, D-Orlando, to speak.
Zachariah chided Eskamani, who told the panel she is a lawmaker.
"You should know better... You know how the House runs in the state of Florida. So you should obey the same rules," he said.
Treatment for transgender people, and youths in particular, has become a fiercely debated political issue in Florida and other states. Prominent medical groups and the Biden administration support treatments for gender dysphoria, while many Republicans such as DeSantis, who is widely seen as a top contender for the GOP presidential nomination in 2024, maintain the treatments should not be provided to people under 18.
Also this year, the DeSantis administration issued a rule preventing Medicaid reimbursements for gender-affirming care for transgender people of all ages.
That rule is being challenged in federal court.
During Friday's news conference, Chriss, a lawyer who represents plaintiffs in the lawsuit, tried to reassure transgender Floridians and their families.
"We've got your back. We are actively litigating the Medicaid ban and we will fight this one as well, and these things cannot stand. These folks know that it's unconstitutional. They know that it's wrong and they're doing it," she said.