^Are Castor oil and other so-called natural inductions safe?
From Laurie's Thoughts on Childbirth Frequently Asked Questions
In midwifery and homebirth circles, ingesting Castor oil is a commonly accepted way to induce labor. I have a few warnings about this and other so called "natural" ways to encourage labor when the body and baby are not ready for birth. First of all, this is a sure fire way to bring about dangerous complications. Yes, I know that many women use castor oil without disastrous results. And yes, generally castor oil is so mild that if your body isn't ready to give birth it won't anyway. BUT, there is the increased risk of fetal distress due, among other things, to dehydration via diarrhea. There is also the fact that being stuck on the toilet with abdominal cramps is a miserable way to begin labor and can put a downward spin (no pun intended) on the whole experience in that sense, right from the start.
My advice for anyone who wishes to induce labor is firstly to seriously examine why you want to start labor artificially at all. Almost all women get to the point in pregnancy where they don't want to be pregnant anymore. See the article How long should a woman feel comfortable going overdue? for more information on going "overdue." This anxiety is natural, but outside pressures from over-eager friends and family, husbands and even birth attendants can make it difficult to do the best thing for the baby's sake. The health of mom and baby must be of foremost concern however, and if you find that you want to induce because of such pressures, then for your child's sake you should not give in. This is a wonderful opportunity to begin to take the full responsibility for the health and well being of your child that is rightfully yours already.
Alternately, sometimes a woman's "care providers" place pressure on her to conform to a standard length of pregnancy. Are midwives or doctors frightening you with predictions of rare complications? If so, you should consider this a serious warning signal that further, more serious interventions and mistrust of the labor process are ahead. In this case you will of course want to take a stand for yourself and your baby (and involve husband or other support). Do it now rather than later when you are more easily manipulated (intentionally or unintentionally - doesn't matter) in the throes of labor.
On the other hand, there is the chance that there is some other specific risk (imagined, iatrogenic, or real) to you or your baby involved in staying pregnant past a specific date. In this case I would ask if you have become thoroughly informed of the risks of induction (premature birth and all it's inherent complications, increased risk of Cesarean delivery, fetal distress, these are a few that come to mind) and how they weigh against whatever this "risk" of continued pregnancy is. You must also take into account the chances of false diagnosis in your specific case. Tests, technology, and experts all can be, and frequently are, wrong. Also, if there really is a serious medical problem, consider whether or not the increased stress of induction might place one or both of you at even greater risk than continuing as your body knows it should would.
Secondly, I suggest something that may strike some as surprising: frequently make love and have orgasms, whether by yourself or with your partner! There are numerous benefits to any labor in doing so, including but not limited to the fact that semen ripens the cervix (it is nature's intended prostaglandin gel insert - the stuff they give women in the hospital is actually pig semen!), nipple stimulation encourages the production of a natural amount of oxytocin (synthetic oxytocin or "pitocin" or "pit" is much stronger and therefore brings on harder, more painful contractions in most cases which can lead to uterine rupture, maternal exhaustion, fetal distress to name a few, and it has many contraindications and warnings -- ask for the package insert...), and simply being loving and intimate with one's partner naturally relaxes the woman's entire body which is essential to a safe, complication free birth, not to mention the fact that it bonds the couple immeasurably around this miraculous event!
If in the end you decide to go ahead and take Castor oil or other such induction methods, I advise you to only do it with the approval and awareness of your birth attendants (if you have any), as they need to be ready, willing, and able to respond to any emergencies it might cause, as well as being able to organize their care around your plans (for example you wouldn't want to cause the baby to be born when your attendants were planning to be away for the weekend if you don't want to give birth without them, and for another example, you wouldn't want your attendants to unknowingly combine induction methods that are incompatible.) Still, I hope you'll seriously consider trusting in the inherent wisdom of your miraculously made body and enjoy a joyous, empowering, complication-free birth.^