First of all, gynecomastia is far from being the only symptom of an elevated blood-estrogen level. Perhaps an equally important aspect is the ratio of free testosterone to estrogen. In order to prevent the multitude of symptoms brought on by an elevated E level, one is expected to lower them via aromatase inhibitors, which essentially either compete with estrogen in the binding to receptors, or inhibit its production by binding to the aromatase enzyme, thus inhibiting testosterone from converting to estrogen.
Nolvadex, as we know, is merely a SERM. The key letter being “S” for selective estrogen receptor modulator. By “selective” it only binds to estrogen receptors in the breast tissue, but it also stimulates LH and FSH production. For these reasons, it’s a bad idea to incorporate Nolvadex continuously through a cycle, since you would be desensitizing the leydig cells with the constant bombardment of Nolvadex. Oh, and it’s speculated to possibly decrease IGF levels, too.