A total of 27 studies, pooling 7928 transgender patients who underwent any type of GAS, were included. The pooled prevalence of regret after GAS was 1% (95% CI <1%–2%). Overall, 33% underwent transmasculine procedures and 67% transfeminine procedures. The prevalence of regret among patients undergoing transmasculine and transfeminine surgeries was <1% (IC <1%–<1%) and 1% (CI <1%–2%), respectively. A total of 77 patients regretted having had GAS. Twenty-eight had minor and 34 had major regret based on Pfäfflin’s regret classification. The majority had clear regret based on Kuiper and Cohen-Kettenis classification.

Research by Medical Accident Group found that 65% of people they polled regretted their cosmetic surgery, though 28% were very happy with its results.

Of 889 studies identified, 73 patient studies and 6 physician studies met inclusion criteria. Among the 73 patient studies, 57.5% examined patients with a cancer diagnosis, with breast (26.0%) and prostate (28.8%) cancers being most common. Interestingly, self-reported patient regret was relatively uncommon with an average prevalence across studies of 14.4%. Factors most often associated with regret included type of surgery, disease-specific quality of life, and shared decision making. Only 6 studies were identified that focused on physician regret; 2 pertained to surgical decision making. These studies primarily measured regret of omission and commission using hypothetical case scenarios and used the results to develop decision curve analysis tools.

Tl;dr: Cosmetic surgeries have massive regret rates of around 65%. Cancer surgeries can have rates of 14.4% regret, many times for life saving procedures. Trans people have a 1-2% regret rate, with trasmasc bottom surgery being the highest rate of regret at 2-3%. This includes even 'cosmetic' surgeries that cis people would generally have high rates of regret, but are gender affirming for trans people.