There are also medicinal benefits associated with ginger oil. According to "A Complete Guide To Understanding and Using Aromatherapy For Vibrant Health and Beauty," ginger oil is effective at relieving menstrual cramps and easing the symptoms of motion sickness and jet lag.. Ginger oil is believed to be effect at boosting the immune system and is used to ward off cold and flu symptoms. It is also thought to be effective at treating respiratory infections and is used to ease sore throats. It can be used to alleviate queasiness and feeling of nausea caused by a hangover. Ginger oil is believed to be effective at treating diarrhea, relieving gas pain and stimulating the appetite.