I'm on my 5th round with meds. 2nd with Femara. I'm on the highest dose at 12.5mg (5 pills/day) for 5 days. Side effects headaches and hot flashes. I've tried up to 100mg of clomid and only got 1 follie. On this high dose round I got 3 follies 1.7, 1.3 and 1.2. My IUI cycle was cancelled due to breakthrough bleeding, but that was due to start the meds mid-cycle due to PCOS and no activity in the ovaries. The bleeding as stopped so DH and I are trying timed intercourse instead this cycle.
TBH Femara is a lot more gentle on your system, less side effects and actually more people have better follicle results with Femara over clomid from what I've read.