They market 1-AD and even 4-AD somewhat as not aromatizing to estrogen very easily, but that doesn't mean that it cannot (4-AD moreso than 1-AD). Not only for it's anti-estrogen effects, you'll need 6oxo to restore you natural test production because YES 1-AD will suppress your natural test levels, if you don't take something post-cycle you'll very much likely crash pretty hard and lose your gains................do a search for 1-ad, you'll see what people have to say.