Masteron is that it is actually a weak (though useful) anti-estrogen, and that’s where a lot of its “hardening” properties probably come from, and why it’s so useful in precontest cycles. Masteron may actually interact with the aromatase enzyme to inhibit aromatization (conversion/metabolism) of other steroids into estrogen. Additionally, Masteron seems to be able to interact with estrogen at the receptor site. I think this explains it’s “hardening” properties, because with less estrogen in your body, you’ll be holding less water and therefore appear harder. This is also why people say it “only works” at a low bodyfat percentage. When you take the water retention off of a fat person, you still have a (dryer) fat person. And if you aren’t using a lot of different aromatizable drugs (and are using them in low doses), or drugs that potentiate estrogen’s effects (and I’m thinking about the 19-nor family here) then Masteron is likely to be the only anti-estrogen you need. Masteron Enanthate is especially effective for this purpose because it has a very long active life and relatively constant blood plasma levels.
Lets look at an example. Your doctor has you on testosterone replacement. You are 45 and have had low test since the age of 40. This condition is very very common. Low testosterone has all sorts of negative health repurcussions. Normal testosterone levels are between 300 and 1100 ng. You want to be at around 1100.. Your doctor wants you around 700-800. To do so he prescribes exogenous test at 180 mgs/week. That amount puts your total test at 760 ng, and your fee test around 10. Adding Masteron increases your free test to 19, Your total test is the same, but your free test, the test you actually use, is much more.