The dementia risk with HRT really depends on formulation, route, dose, age at start, and duration of use, among other factors. The WHI Memory Study - the largest randomized clinical trial (RCT) - linked oral conjugated equine estrogens (CEE) plus synthetic progestins (MPA, medroxyprogesterone acetate) to higher dementia risk, but that’s a very different regimen from the preferred transdermal estradiol with micronized progesterone used nowadays. The only RCT I’ve come across on that combo, KEEPS-Cog, found no cognitive harm, though it only studied early starters and short-term use (about 4 years). I think it’s fair to say the exact dementia risk with this bioidentical regimen remains unknown. I’m personally choosing to take that small, unquantified risk and keep reassessing as new data emerge, since osteoporosis is 100% my reality now.