Nope, you're thinking of the SERM nolvadex. You do not want to use nolva on cycle with a 19 nor, as it can increase progesterone and possibly cause issues. Really, I wouldn't suggest using nolvadex on cycle anyway, no matter what gear you used. For on cycle, I would use an AI, like adex, to lower estrogen in the body vs just block it at the receptor. You can use caber as well, to control prolactin, if that becomes an issue.