Puberty blockers are drugs that stop the body’s natural puberty from happening. They work by halting the release of sex hormones, so physical changes like breast development, voice deepening, or genital growth do not occur.

The people who used these drugs for years say the claim that blockers are “completely reversible” is false. Once the normal puberty window is missed, the body cannot “catch up.” Instead of being merely delayed, that period of puberty is lost forever. Detransitioners report permanent deficits: under-developed genitals, lowered bone density, possible IQ reduction, infertility, and the inability to experience normal sexual function or orgasm. Even if the drugs are stopped, growth resumes only partially and never makes up for the lost time.