I did look it up on various sites which all said standard dose is 1000mg/day. But mainly the vitex I bought came with a how-to pamphlet and dosages which had the daily dose at around 1000mg/day. (it said 20 drops = 542mg, and daily dose is 15-20 drops 2x/day). I only took mine once a day in the morning. I bought it at a health food place which has a doc/naturopath there who I discussed it with as well. He was very knowledgeable about it. My own doc had to look it up and was ok with me taking it, but she wasn't too concerned as it's an herbal supplement and I think she kind of rolled her eyes a bit that I would bother making an appointment to ask.