YES...I had very long cycles (45-50 days) and ever since I started Agnus Castus (4mg per day) I have them reduced to between 30-40 days. I am TTC and take it only in the Follicular phase, since the effect of Agnus Castus on pregnancy is not well known, so I stop taking it after I get my Positive OPK or temperature shift, then start it again from next cycle (CD1 or CD2).