REPOSTED:
Do not dose your anti-e's EOD. This is a common mistake that has become standard because misinformed people recommend it unknowingly. I've even seen moderators do it. When you dose every other day you cause your blood levels of estrogen to go up and down. Those ups are what cause the side effects as the levels may spike.
The reason people do it is to save money. This is not a place to cut corners.
If you're using 600mg then use 1 ED. Keep in mind that arimidex is very weak by today's AI standards. In men it only inhibits an average of 59% of the estrogen and that's not on cycle, that's without steroids. This is one reason we recommend people use AIFM because it's more powerful on cycle.