Puberty blockers

Puberty blockers block the hormones — testosterone and estrogen — that lead to puberty-related changes. They pause puberty for as long as the person is taking the medication; they cannot be taken after puberty or undo the effects of puberty that has already started. The effects of puberty blockers are fully reversible. If or when a youth stops taking them, their puberty resumes from where it left off (Source).