It's "the other type" of hormonal treatment for menopause, it's not always called HRT, my GP calls it the alternative to HRT.
Prescription only, no problem to get prescribed in the UK by most GPs. It's listed in the treatments pages on this forum as Postmenopausal: HRT (e) on the list, they call it Livial but that's just one brand, tibolone is the generic name of the medicine.
It is classed as an anabolic steroid that prevents bone loss after menopause, but it has also been found to lessen cardiovascular disease and other aging illnesses in older women and help menopausal symptoms.
I don't know what it's made from, chemicals in a lab I guess, it's one tiny white pill a day and I found it to have no bad side effects at all which was quite something after the horrible side effects of the oestrogen &progestin types.
The only reason I'm messing with the "normal HRT" again is because I couldn't have tibolone for a while, it clashed with another medical thing.
I'm allowed it again now so will probably switch back quite soon.