I just thought I'd let you all know that I got a good answer to my question on steroidology.com from EINSTEIN1905:
There have been studies to show nolva decreases serum IGF-1 levels.....the majority are done in breast cancer patients.....breast cancer patients have increased IGF-1 production in mammary fat pads, so it's most likely that the reduction in IGF-1 has much to do with reducing this abnormally high production of mammary IGF-1 production and not so much at all on hepatic IGF-1. Intramuscular IGF-1 (IGF-1Ea) is what's most important to us, and there's no reason to believe that this is affected by nolva.