Hi
I've never heard of transdermal or any other oestr needing to be taken at same time as utrogestan - that said I've never done any gel let alone sandrena. Plenty of people here put gel on morning and evening though, or change their patches every 3.5 days as I used to do, so it doesn't sound right - unless GP meant easier to remember!
Utrogestan can make you drowsy, so night-time definitely. It is best taken 2+ hours after food so on an empty stomach - that's to do with absorption. I think I read somewhere that weirdly food actually increases absorption of utrogestan (which is the opposite of what you'd expect) - and when you're starting out you especially don't want to be absorbing excessive (or taking it in morning!).
That said, the leading meno consultant I'm very lucky now to see said when I asked him - for me it's challenging for some of same and some different reasons - said ideally 2 hours (which is in itself obviously an approx - many medics suggest a bit over 2 hours for empty stomach, and it varies from person to person) but he wasn't going to lose sleep it if was a bit less, but just not to take it on a full stomach (or too close even before to food). So fwiw - and I'm not a doctor - I'd suggest definitely at night, as long after food as you can (just before lights out!) and don't stress particularly on holiday if sometimes that's a bit under 2 hours.
HTH
xx
