A further update on this, if anyone is still reading...
It's improving a lot. It's hard to compare things retrospectively, but it's about as powerful as it was in the past.
Also, this week has been weird. I have been extremely horny. I did suffer a slight loss of libido in the first week (I put that down to my mind), but now I am the complete opposite.
It's to the point where I walk around town and all I can think about is how hot someone is and that I want to mount them there and then (OK, slight exaggeration there!). If I wasn't a sensible person I'm sure I'd be humping their leg like a dog!