[Heaven's Night]

Don't do HRT if you're not transitioning. You can't pick and choose the physical changes it does to you. It can fuck up your mental health badly, its not a thing for cis men to dabble with. The changes it does is more than physical, much more and you might get more than you bargained for.

For the method of admin, oral pills are the worst, mainly for liver metabolism causing it to elevate blood clotting factors. Followed by patches and gel. Injection is the best. For reaching female hormone balance. One method is not better than the other considering body changes, but injection is known as the gold stadard for HRT for a good reason as nothing makes such high levels so easily. But then again, there are many stories of people stalling when switching especially to EEn (estradiol enanthate) for some reason.

But since you're a cis male(?), just don't do HRT, its not for you if the only body change you want is boobs, you're likely better off with NBE. HRT would give you everything else too and you don't probably like it. Cis guys get their mind fucked up from it, lose erections, feminise all over other than just growing boobs and its also morally questionable that cis guys take stuff which is actually meant for cis and trans women to treat actual medical issues rather than seeking self pleasure from having boobs... Then again, who am I to gatekeep anyone. Doctors very likely will do that anyway as they're not handing this stuff out like candy.