The anti-aromatase effects of aromasin seem to last about 7 days:
Cancer Research 52, 5933-5939, November 1, 1992
Phase I and Endocrine Study of Exemestane (FCE 24304), a New Aromatase Inhibitor, in Postmenopausal Women
T. R. Jeffry Evans, Enrico Di Salle, Giorgio Ornati, Mercedes Lassus, Margherita Strollin Benedetti, Elio Pianezzola and R. Charles Coombes
http://cancerres.aacrjournals.org/cg...int/52/21/5933
as brass-man put it:
Using once weekly aromasin would still probably be a better option than arimidex or letrozole for PCT with Nolva. As a weekly dose of aromasin would no doubt afford more anti-aromatase activity than dramatiacolly reduced arimidex and letrozole.