I tried using vitex.. it did not work for me I took an entire bottle before I gave on anything happening. since i stopped having a period for like a yr. I thought i would give that a try but i never had a period with it. Now I am seeing a specialist about my issue. It depends on what u are taking it for to decide how long it will take to work.. I got mines from
www.ovarian-cysts-pcos.com/vitex.html I bought mines from that web site check it out!! the info on there might be able to help u... Good luck !!!
I did have another question I don't know where else to find it at gnc doesn't sell it anymore, nor do walgreens, walmart or meijer.