Your question raises several topics of discussion:

Are you definitely overdue? Aside from babies born truly prematurely, more women go past their dates than before (and very few go exactly on their due date), calling the method used to calculate into question. Like blood type, hair color, body frame, and almost every other physical characteristic, there is no one rule that fits everyone. Due dates should be taken as a range; some women naturally go two weeks early or late.

Why are you overdue? If your body or baby is not ready for birth, any method of inducing labor can pose risks. Possible reasons include an unripe cervix (usually indicating that you are not truly due yet), emotional doubts or fears that cause you to unconsciously "hold on" (this is not necessarily under your control, but may be resolved by talking through your feelings), or the baby's position (if the baby's head is cocked even slightly, or "asynclitic," it may not put enough pressure on the cervix to stimulate strong contractions. Sometimes physical activity such as walking up and down stairs or swimming can resolve this situation ).

Is it posing a threat to you or your baby? Although overdue babies do have higher rates of some problems (including stillbirth), the rates are not greatly higher. Despite the fears of many doctors, most overdue babies are in no danger. If you are healthy, your baby is still active and the volume of amniotic fluid is good, chances are everything is fine and the baby just needs more time. A non-stress test and/or a biophysical profile will help determine this. Usually, more patience is all that is called for.

Have you tried other methods to stimulate labor? Physical activity, making love, nipple stimulation, homeopathy and acupressure have all been documented as effective ways to begin labor, without the possible side effects of drugs or herbs. Tea made from parsley or cumin seeds will also often stimulate contractions, and both are gentle and virtually free of side effects.

Herbs have been used successfully for thousands of years to stimulate labor, but they can be powerful and they can have side effects; therefore they should be used under the supervision of someone familiar with their use. Blue cohosh (caulophyllum thalictroides) works because it has an oxytocic effect on the uterus. Oxytocin is a hormone that causes uterine contractions. Many midwives and herbalists recommend using blue cohosh together with black cohosh (cimicifuga racemosa) because they seem to work synergistically. Either tea or tincture can be used, and small, frequent doses (every 30 minutes to one hour) are both safer and more effective than a single large dose. No more than 6 to 10 doses should be taken in one day, and you should skip a day between treatments. Side effects can include raised blood pressure, elevated pulse in mother and baby, and allergic reactions.