Is HRT for FTM or MTF?

Could you please elaborate on the application of Hormone Replacement Therapy (HRT) for individuals who identify as Female-to-Male (FTM) or Male-to-Female (MTF)? I'm particularly interested in understanding how HRT is tailored to suit the specific needs and goals of these two groups. Could you also discuss any potential risks or side effects associated with this treatment, as well as the general process of undergoing HRT? Additionally, I'm curious to know if there are any specific guidelines or recommendations for individuals considering this type of therapy. Thank you for your insights.