Nigella - you need to discuss this with a Pharmacist.
I found this:
"What are the possible side effects of Vagifem®?
Vagifem® is only used in the vagina; however, the risks associated with oral estrogens should be taken into account. The most commonly reported side effects of Vagifem® include: headache, breast pain, irregular vaginal bleeding or spotting, stomach/abdominal cramps, bloating, nausea and vomiting, hair loss, fluid retention, and vaginal yeast infection. ...... "
I couldn't find out if lactose is involved.