Chasteberry is a mediterrenean herb that is used for all female hormone related problems. It balances the hormone levels. It does not include any hormones itself, so it is quite safe and a good substitute for hormone replacement programs. Black cohosh and Dong Quai are other herbs that have similar effects on female hormone balance. Most female herbal formulas include these three herbs together.
There is an informative site that you can read about these herbs.
You can find the capsules of these herbs in most stores. I know that Solgar has a femal herbal complex that includes these herbs, there may be other brands as well, just visit a nearby health store to find out.