The problem with the studies showing arimidex is bad is based on subjects (ie mice) that are either producing normal amounts of test or on test repleacement at normal doses. From the blood tests I have seen on those using ana while on cycle, they still suffer from highly elevated estrogen levels. Which, as Ulter pointed out in a previous thread on this issue would mean that the majority of the lipid problems is likely not the fault of ana but the cycle itself.