Hi, I'm 68 & came off HRT 3 years ago, I'd been on Femoston Conti low dose, & for several years I'd cut the tabs into 1/3rds, all I needed to control flushes.
Insomnia kicked in last Oct/Nov, & weirdly flushes kicked back in at the same time, a few 'medium' ones daytime, & 2 or 3 at night, 'spontaneously combust' level!
I decided to try Black Cohosh (from Holland & Barrett) once again, though in my 'salad' meno days it had proved useless. I have found that this time it definitely did tone down my current flushing somewhat, all fewer & milder (manageable).
I've gone back on HRT (past 3 days), though the reason isn't relevant to your question.
Be careful with Black Cohosh if you're on other meds.