Yes, I've been running nolva on its own for the majority of my PCT with a standard 40/40/20/20 protocol. There has been some evidence in some research to suggest that clomid has purpose in the very very early stages of PCT, but in my eyes it is not enough to justify its use (and then you have to get into the high dose of clomid you'd have to use to elicit that effect, the cost to benefit ratio, and risk the stupid sides it comes with). Most of the research you'll find points to using both because that's been passed down from generation to generation to generation without revision. It's an outdated practice with research showing that clomid's days of being a very important addition to PCT is effectively over.