Will someone be able to grow out of it / live in their assigned gender / be cured?
Being trans is not an illness of any kind, nor is it something that can be “cured”. Most of the medical procedures carried out on trans adults are irreversible, although puberty blockers are only temporary, and can be stopped and will not cause any permanent changes, if the patient changes their mind about treatment.
Detransitioning, the process of returning to the gender assigned at birth, occurs in a small percentage of the trans population. For example, in 2015 the U.S.-based National Center for Transgender Equality surveyed 28,000 people and found that only 8% of respondents reported detransitioning, with 62% of those people only detransitioning temporarily.
Most countries have an extensive system in place to ensure that patients are provided with all the information required to make a decision regarding medical transition before any life-altering treatments are considered. For example, in the UK patients must be seen by a member of the psychological team before any medical treatment is discussed. It is important to support trans people in their decisions and allow the professionals to handle the care of the patient; it is crucial that trans people have a support network as transition can be very stressful.