Hi Kathleen
I agree with what's already been said. I have been using it vaginally for much shorter time than Cassie - for almost 3 years, and have never used it orally. I think I explained I get mine on the NHS - but I arrived at my dosage and cycle through discussions on here over the past 3 years, from published papers on the subject, and from what others have reported about their private gynaes - as Taz said.
I am lucky in that my GP is enlightened and she agrees with what I am doing - both the two monthly cycle and the vaginal use - but she has prescribed Cyclogest (progesterone pessary/suppository) off licence for years anyway.
It is exactly the same capsule (Utrogestan) which is prescribed orally and which some of us use vaginally, and yes the same capsule (200 mg) is available and prescribed vaginally for fertility treatment.
So - the answer is, if you want to use it vaginally due to side effects from oral use - then yes you can. I can't remember how many days you will be taking it for but some women could probably get away with a lower dose than 100 mg vaginally for endometrial protection on the continuous combined regime (and with a low-medium oestrogen dose) - although a lower dose isn't available. I know some women have tried every alternate day vaginally (for a continuous combined - no-bleed regime) but probably best only to do this is you are sure you are getting scanned regularly and with doctor's approval.
Yes I'm still learning!
Hurdity x