I prefer to take it vaginally, I think the side effects are less. I took 200mg orally last month for 10 days and I have a problem with vertigo at the moment....it started after I had been taking 200mg for 10 days orally so I think there may be a connection. Not sure tho..could be a virus or labyrinthtitis, its not nice tho. This month I'm going to try 100mg taken vaginally for 12 days and see if I fair any better...I don't get much of a bleed if any tho, whatever dose I take. I also have to douche to get the remains of the utrogestan out . Like many on here, I have grown to dislike the utrogestan phase, I also seem to develop a brain fog after about 7 days use.