Asked on Tumbler recently:
Is there a legitimate reason why so many FtMs are not prescribed estrogen blockers in tandem with testosterone? I just find it odd and I don’t understand why blockers + hormones are standard procedure for MtFs but not FtMs.
I suspect most individual doctors don’t prescribe them because the guidelines they follow for treatment — like the WPATH SOC and the Endocrine Society guidelines — don’t recommend them.
As for why the standards of care don’t recommend them? Because they’re not seen as beneficial in most cases. Testosterone is a highly impactful hormone that alone produces the desired physical changes, and years of clinical observation & study have determined that blocking estrogen doesn’t generally confer any additional advantages. This isn’t to say that estrogen blockers are NEVER prescribed. WPATH, for example, recommends blockers “to assist with menstrual cessation early in hormone therapy” and in cases where the patient may have certain other issues.
In MtF HRT, testosterone blockers are used because they do create measurable benefits by themselves, such as in retarding the growth of body hair, and because they allow MtFs to take less estrogen for clinical effect (high doses of estrogen carry a lot of risks). On the other hand, there’s a lot of debate about the prescribing of progesterone in the MtF regimen, as data has suggested progesterone may not have any real clinical effect and it’s ridiculously expensive in some cases. As such, many doctors don’t prescribe progesterone anymore, or wait to prescribe it until they see the initial effects of estrogen & t-blockers alone.