This is probably not a reply your friend will want to hear - but I went off the pill in June 2006 and haven't had a period since

I too have had all the tests and the only thing wrong is a hormone imbalance apparently caused by stress.

I've been trying to fix this by having acupuncture, but I don't fit into any of the classic 'problem' areas, so this hasn't worked for me. But it might work for you friend.

I'm seeing a fertility specialist in 5 weeks time, and will be started with assisted reproduction, probably ovulation induction (as I'm not ovulating!).

I would rec'd your friend sees a fertility sepcialist as in my experience GPs tend to not take you too seriously, esp if you are under 30.