Study	Reason for exclusion
Asscheman 2011	Mortality rates in transgender people receiving long‐term cross‐sex hormones. A cohort study. Adequate controls are missing. Interventions are not clearly defined
Colizzi 2015	Increased prevalence of metabolic syndrome among individuals with gender dysphoria treated by cross‐sex hormonal treatment. Study without adequate comparator group.
Fighera 2018	Hormone therapy has been associated with changes in bone and lean/fat mass. This study assessed bone mineral density, appendicular lean mass, and total fat mass in transwomen undergoing cross‐sex hormone therapy. Study without adequate comparator group.
Fisher 2014	This study aimed to assess differences in body uneasiness and psychiatric symptoms between gender dysphoria clients taking hormone therapy and those not taking hormones (no hormone therapy). A second aim was to assess whether length of hormone treatment and daily dose provided an explanation for levels of body uneasiness and psychiatric symptoms. Cross‐sectional design.
Fisher 2016	The objective of the study was to assess whether hormone therapy‐related body changes affect psychobiological well‐being in gender dysphoria. Study without adequate comparator group.
Giltay 2000	Hormone therapy effects on the skin (hair growth rate, density, and shaft diameter by image analysis; and sebum production) of transsexual patients receiving cross‐sex hormones. It is a case series, adequate controls are missing.
Haraldsen 2005	Hormone therapy effects on cognitive performance. Study without adequate comparator group.
Haraldsen 2007	The effects of cross‐sex hormones on bone metabolism (bone mineral density, total body fat, total lean body mass) in patients with early onset gender identity disorder. Study without adequate comparator group.
Miles 2006	The study was designed to examine associations between oestrogen and cognition (memory, including visual, spatial, object and location memory, other cognitive abilities that show reliable sex differences, including verbal and visual‐spatial abilities, and mood variables). The cross‐over design used was comparative, but did not used randomization or quasi‐randomisation.
Schlatterer 1998	This follow‐up study was carried out to validate the effectiveness of cross‐gender hormone therapy embedded in a multistep treatment concept for transgender patients. Study without adequate comparator group. This study lacks adequate controls.
Toorians 2003	To find an explanation for the different thrombotic risks of oral ethinyl estradiol and transdermal 17‐beta‐estradiol use, the researchers compared the effects of treatment of male‐to‐female transgender people with cyproterone acetate only, and with cyproterone acetate in combination with transdermal 17‐beta‐estradiol, oral ethinyl estradiol, or oral 17‐beta‐estradiol on a number of haemostatic variables. There is no adequate control group.
Van Goozen 1995	Effects of sex hormones to the establishment of gender differences in behaviour, a large battery of tests on aggression, sexual motivation and cognitive functioning was administered twice: shortly before and three months after the start of cross‐sex hormone treatment. The study does not have an adequate comparator group.