By the by, this is a fairly small study of 48 trans-identifying patients but:
'3.2.4. Undesired Treatment Outcomes (Stopping Hormones, Abnormal Blood Test Results, Side Effects and Complications)
Nine patients had stopped hormone therapy; one related to practice policy because they had not attended any GIC follow-up (the patient has restarted since the audit). Thus, eight patients had stopped hormones voluntarily (20% stopping rate; six trans men, two trans women). These patients had been on treatment for a mean of five years (range 17 months-10 years). Four transmen had comments in the records that related to a change in gender identity or detransitioning (4/41, 9.8%): “Would like to gradually detransition”; “No longer wish to live your life as a male”; “Has decided to detransition…. Feels comfortable having decided to dress and appear more feminine; “Feels it was a mistake, identifying as non-binary now”. None of these patients had undergone any gender related surgery. They had presented at a mean of 18 years of age, taken testosterone for a mean of 18 months, and currently presented as female (three) or non-binary (one).
The other four patients who had stopped hormones continued to present as trans (two women, two men): one, who had experienced orchidectomy, had a record of regret (“No hormonal treatment currently, regrets gender reassignment”); one had a medical reason noted for stopping (“problems with PV bleeding despite androgen”); and two had no specific reason for stopping in their record, but it was documented that they had stopped.
In 15 cases (37%) of patients on hormones, levels had been found to be out of target range at one or more point during the course of therapy. Twelve trans men had transiently raised testosterone; one with a level of 120 nmol/L (over four-fold advised peak levels) who now has injections at the surgery instead of self administering. Three trans women had transiently raised estradiol levels above target range (highest, 1151 pmol/L). Transient polycythaemia (HCT > 0.5 L/L) was found in 9 trans men (highest haematocrit 0.57 L/L).
Five trans men (16%) had documented complications: severe acne attributed to testosterone by dermatologist (two); unwanted male pattern balding (one), vaginal bleeding (one); and vaginal atrophy requiring topical oestrogen (one). Two trans women (20%) had documented complications: severe vaginal wound infections (one resulting in sepsis requiring admission and intravenous antibiotics, the other in vaginal stenosis).'
...
'In terms of detransition rates, one meta-analysis reports rates of less than one percent 50] but the primary studies are inherently flawed by loss to follow up. A recent UK GIC case note review found a detransition rate of 6.9% 51]. Thus, the detransition rate found in this population is novel and questions may be raised about the phenomenon of overdiagnosis, overtreatment, or iatrogenic harm as found in other medical fields.'
www.ncbi.nlm.nih.gov/pmc/articles/PMC8775415/