Hi Scottie56
Looks like Osphena is the brand name for Ospemifene in US not UK. Ospemifene is the active ingredient in the drug known as "Senshio" which appears to be licensed in UK. 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).
The difference is that it is a orally ingested drug rather than locally applied product as other vaginal treatments are. If you want to have chapter and verse on VA then please look at Maryjane's posts who has written a book called "Me and My Menpausal Vagina" Jane Lewis and has a private vaginal atrophy Facebook group which you could ask to join. Also there are threads on here - one called "The Burning Club" started by Dancinggirl in the Private Lives section.
It's not my area of expertise but you may well benefit from systemic HRT if you are able to take it as well as local oestrogen - some of use both in order to stay comfortable, and some have a regular regime of moisturisers and lubricants too.(I use full HRT, Vagifem every 3 days, and estriol cream when I have my HRT induced withdrawal bleed and sometimes on extrenal areas).
Personally I would not want to take an oral preparation like this which could have differential effects on different areas of the body - so I would say if you are considering this route then systemic HRT may be better - depends on your other symptoms of course.
Hurdity x