Caraway essential oil is steam distilled from the caraway seed of the plant Carum carvi. This belongs to the Umbellifrae (also known as Apiacae) family and the genus Carum. Other similar plants belonging to the same family are fennel, parsley, carrot, angelica, anise, celery, chervil, coriander, cumin, dill, and parsnip, just to name a few.
I have never used this oil in my practice because it doesn’t have many traditional uses in Aromatherapy and other more common oils are usually used for therapeutic value, like fennel. I couldn’t find a typical analysis, which gives the breakdown of chemical constituents in an oil, but I have found some basic information naming the major active ingredients.

Carvone – pic via http://www.scienceforums.net
According to Wikipedia:
“The fruits, usually used whole, have a pungent, anise-like flavor and aroma that comes from essential oils, mostly carvone and limonene.[10] Anethole, generally regarded as a minor product in the essential oil of this species, has also been found to be a major component.”
And from a paper 1994 UPDATE ON ESSENTIAL OILS IN SASKATCHEWAN SPICE CROPS by F. Sosulsk$, A.E. Slinkard and G. Arganosa:
“Carvone contributes the typical aroma of caraway seed and the carvone to limonene ratio in the essential oil should be 60:40”
It is important to note that even when we have a chemical breakdown of an oil, we must consider it as a whole and remember the old adage “the whole is greater than the sum of it’s parts”. This means we can expect an oil to behave in a certain way when we find out what molecules it contains, but there will also be a unique signature that lends itself to other properties too.
Caraway essential oil could be used for digestion, as for fennel and aniseed. Regulating menses and attendant pain could also be helped by caraway oil, but I would probably just stick with fennel. In these instances I would dilute a drop or two in some carrier oil and rub all over the stomach and lower back. I would also use caraway for coughs and lung problems (especially catarrh) in a steam inhalation
According to Aromatherapist Danielle Ryman, fossilized caraway seeds were found in Neolithic dwellings in Switzerland, and in Mesolithic sites, which means that it was in use up to 8,000 years ago. She also says the Ancient Egyptians used the spice in religious rituals, (like many aromatic plants and flowers) and in cooking to make foods like bread and onions more digestible.
So it seems the modest caraway seed has similar properties to other Umbellifrae seeds and you can check out my article Star Anise, Aniseed and Fennel Essential Oils – What’s the Difference? to understand more about those oils -their similarities and differences.