Hi Kelly,
I wouldn't say anything is 'inconsequential' to avoid the risk of invalidating a patient's experience. Every change, no matter how big or small is consequential depending on the patient's perspective.
The research (https://core.ac.uk/reader/153399329?utm_source=linkout) published by the endocrine society states that most bodily changes of feminizing hormones takes a least 3 - 6 months to trigger the onset of change, and up to 2 - 3 years for maximum change to occur. Therefore, I recommend 12 months because it allows for at least some meaningful change in one's body before considering their next treatment options.
Risks and adverse effects are a part of life when taking any medication. Yes, one might theoretically develop a DVT 2 weeks into HRT but that doesn't mean the trial shouldn't have proceeded since we cannot predict the future. It is fine as long as the patient is informed of the risks before proceeding.
I'm not someone who is very overly eager in prescribing hormones because I understand this is a heavy and consequential decision. But when I do, I want to make sure my patients are making meaningful decisions that will ultimately lead to some kind of closure. To me, taking HRT for 3 months on its own not only accomplishes very little, but it could be a reflection of severe resistance or ambivalence which is usually a red flag. Having said that, I never say never to my patients so I always hear their stories out before deciding a way forward.
For example, I have a group of non-binary patients who really don't want the full effects of HRT and therefore only take a small dose of it for x number of months then stopping it. That's fine too.
Having said all this, I'd like to point out that HRT may have a very different effect on biological women because they have more estrogen receptors. I've treated a number of patients with PMDD who had a variable response to HRT despite only taking it for a week or two. I bring this up so to avoid the risk of misleading everyone into believing that HRT does NOT affect mood in the short term, because it does. The immediate mood effects HRT has on transgender women, however, is not well documented.
I hope this helps.
S