Puberty blockers can't be started at 18 when youth have already developed: experts

Puberty blockers have been in the spotlight since Alberta Premier Danielle Smith announced plans last week to ban the medications for children 15 and younger, unless they have already started the treatment. Here's what health-care professionals say about the medications and why they are used.

Puberty blockers have been in the spotlight since Alberta Premier Danielle Smith announced plans last week to ban the medications for children 15 and younger, unless they have already started the treatment. 

Smith's views about gender-affirming care have drawn criticism from Prime Minister Justin Trudeau but support from federal Conservative Leader Pierre Poilievre, who says puberty blockers should only be provided after age 18. Here's what health-care professionals say about the medications and why they are used.

Puberty blockers are given by injection to youth experiencing gender dysphoria, where a person's gender identity does not match the sex they were assigned at birth. The medications block physical changes such as breast development due to estrogen or a deepening voice from testosterone. 

Dr. Daniel Metzger, a pediatric endocrinologist at BC Children's Hospital, said the blockers were initially used in the 1990s to delay puberty for children who started developing sexual characteristics as young as three.

Physicians in the Netherlands started administering the medications for gender non-conforming youth in the 1990s before the Vancouver hospital was the first to use them in Canada about 26 years ago, Metzger said.

The effects of puberty blockers are reversible if they are stopped, but taking them allows youth time to decide if they want to continue gender-affirming surgeries, some of which are irreversible.

The average age that youth assigned female at birth start puberty is 10 while those assigned male typically start at 11, Metzger said.