Should cross-sex hormone treatment of transsexual subjects vary with ethnic group?

Guidelines for cross-sex hormone treatment of transsexual people have been developed, but no attention has been paid to the specifics of ethnic groups. South East (SE) Asian male-to-female (MtoF) transsexual people may be able to transition to the female sex with lower doses of estrogens/progestins than Caucasians thus reducing health risks. Female-to-male (FtoM) may virilize less profoundly with standard doses of androgens, but this is probably sufficient to pass acceptably as men in view of the less pronounced sex differences in physique in Asians compared with Caucasians. It is timely that studies in Asians are conducted to get a better insight into their specific needs and risks of cross-sex hormone treatment.