Here is some info about it:
It is in a class of compounds called selective oestrogen receptor modulators (SERMs). These compounds bind to some oestrogen receptors and not others - sometimes acting like oestrogen and sometimes blocking its effects. It binds to oestrogen receptors in the vagina and acts like oestrogen in vaginal tissues "increasing the cellular maturation and mucification of the vaginal epithelium" (NICE).
"
Ospemifene's biological actions are mediated through the binding of ospemifene and its major metabolite to oestrogenreceptors. The relative contribution of the metabolite to the pharmacological effect is estimated to be approximately 40%. This binding results in activation of some oestrogenic pathways (agonism) and blockade of other oestrogenic pathways (antagonism). The biological activity profile in humans is predominantly due to the parent compound.Nonclinical findings show that ospemifene and its major metabolite have an oestrogenlike effect in the vagina increasing the cellular maturation and mucification of the vaginal epithelium. In the mammary gland, they have a predominantly oestrogen antagonist effect.In bone,ospemifene has agonist-likeactivity. In the uterus ospemifeneand its major metabolite haveweak partial agonist/antagonisteffects.These non-clinical findings are consistent with findings from clinical trials, in which ospemifene demonstrated benefits on vaginal physiology without apparent oestrogen-likeeffects on breast tissue"
(Taken from the product info - you can read further info about trials etc here:
https://www.medicines.org.uk/emc/product/9417/smpc )
So basically acts like systemic HRT on vaginal tissues and some part of the body due to its selective action on oestrgoen receptors - hence it is an SERM. So maybe some women prefer to take an oral preparation - and possibly if it has some potential bone protective effects could be helpful for some women? At least it does increase choice even if limited in its applicability.
Hurdity x