The only estrogen blocker I would even think about taking is anastrozole (Arimidex) or letrozole (Femara). These drugs are called aromatase inhibitors, which means they inhibit the conversion of testosterone into estrogen (E2).
I have screwed around with Arimidex in the past and now and then take 1/4 or 1/2 a pill just to test whether I "feel" different, especially in the downstairs department. So far, my tests are unconclusive. And I am also increasingly uncomfortable toying with these drugs as they are indicated only for postmenopausal breast cancer patients. Obviously, not at all (not even close) indicated for men.
Also, there was an infamous canine study that showed finasteride + anastrozole increased prostate volume and testosterone very significantly. Not only could this contradict preventing hair loss, but it can have dangerous long-term side effects that haven't yet been studied. So again, more research needs to be done.
D.