In one study of detransitioners, around half were worried about the medical complications of transitioning.
A study  of 100 detransitioners showed that 49% had concerns about potential medical complications from transitioning.
A second study  of detransitioners and desisters – most of whom were detransitioners who had undergone medical transition – arrived at a higher figure, with 62% citing health concerns as a motivating factor for detransition.
 Littman, L. (2021). Individuals Treated for Gender Dysphoria with Medical and/or Surgical Transition Who Subsequently Detransitioned: A Survey of 100 Detransitioners. Arch Sex Behav. [Link]
 Vandenbussche, E. (2021). Detransition-Related Needs and Support: A Cross-Sectional Online Survey. Journal of Homosexuality. [Link]