It really depends on how long you have been using the treatment, don't even think of reducing until you start to feel any benefits which can literally take months.
You might need Ovestin cream to apply topically to use alongside the Vagirux, its all about patience and finding a regime that works for you. I will say there has been a few posts on here with women not getting on with Vagirux and preferring Vagifem instead, even though they have the exact same composition, apparently.
My regime is Vagifem, Ovestin, and moisturiser every day for two years so far, I have tried to reduce but without success, but I am not on any other form of HRT.