So a bunch of anti-trans hate groups sent a citizen's petition to the FDA demanding regulatory action around "cross-sex" use of estrogen. Although the language is somewhere heated and while we have no indications as to the FDA's intent with respect to this petition, I have no reason not to believe the authors of this article when they describe its potential impact if adopted: https://theneedlenews.com/anti-trans-hate-groups-petitioning-fda-for-registry-of-trans-women-crackdown-on-transition-newly-revealed-document-shows/

The short version: the creation of a registry of all trans women in the US, a federal regulatory requirement for a significant set of gatekeeping steps before estrogen can be prescribed, and authorization to seize any estrogen used without that process having been followed.

The original document can be read here: https://www.regulations.gov/document/FDA-2025-P-7321-0001

They apparently did not see the need to go after trans men here.