@gravity3
The study referred to by mahonlye is considered old news; it was a study on premarin, depoprovera and progestins, linked to the old WHI study.
There is no age limit for BHRT or even some forms of HRT; instead the criteria is now bound to each individual person and their symptoms, not their age.
Newer Less concern with age is tied frequently to the less dangerous BHRT, topical, vaginal delivery which is frequently used and better doctor analysis and follow up.
https://journals.lww.com/menopausejournal/fulltext/2024/05000/use_of_menopausal_hormone_therapy_beyond_age_65.3.aspx
Menopause society new guidance on age and HRT tied to symptoms and not age:
https://menopause.org/press-releases/ongoing-individualized-hormone-therapy-appears-to-have-no-age-limit.
To put this into context, the old concerns were tied to HRT that was synthetic or non identical to the human body.
Plus, concerns that starting a woman on any form of HRT or BHRT might hold a risk of cardio problems. This is because a cardio system with few hormones is prone to stiffen and for plaque to form then when hormones are reintroduced and the cardio system becomes more pliable the left over plaque may loosen and cause a cardio event.
There is less concern now because doctors know to check for any potential problems and many begin vit k with their patients to help with potential calcium in the cardio system.
Then the dangers are less and even eliminated by use of BHRT, topical vaginal and a good doctor who checks and rechecks your health before and during use of hormones.
With this type of use and doctoring the lack of problems is substantial.
Indeed, in a huge population study in France the only group that had a zero percent increased risk of breast cancer was the one that used bioidentical progesterone.
https://cemcor.ubc.ca/resources/does-taking-progesterone-alone-or-estrogen-increase-womens-risk-breast-cancer/