It's always a good idea, like having a SERM on hand. If you get blood work you know what your test and estro levels look like and you can better assess your need for certain supplements. For instance if estro is low you will probably want to run an AI earlier in your PCT as levels will rise faster than if estro was at a normal level. It'll also help you to see if you are totally recovered after your PCT. It's really the only way to know if your PCT was successful or not.