Ginger, the fragrant, knotty rhizome that features prominently in many Asian cuisines, also has a long history in the traditional medicine of the region. For the past 2,500 years it has been used in China, Japan and India to treat conditions such as headaches, nausea, rheumatism and colds. Today, ginger’s most popular uses include relief from arthritis, motion sickness, and nausea caused by pregnancy or chemotherapy. In the United States, ginger is one of the top-selling herbal supplements, accounting for more than a million dollars in retail sales each year.

The reason it works for nausea is that it contains the compounds shogaol, gingerol and galanolactone, which appear to stimulate flow of saliva, bile and gastric secretions. They may also suppress gastric contractions. Galanolactone in particular may work similarly to some prescription antinausea drugs. 

Ginger is generally used in oral doses up to 2 grams daily in single or divided doses. There are very few side effects associated with taking less than 5 grams of ginger per day. Side effects, which occur more often with the powdered form, can include gas, bloating, heartburn and nausea. Taking too much can cause adverse reactions like central nervous system depression and arrhythmia. Some evidence cautions use with blood thinners, H-2 blockers and blood sugar or blood pressure medications due to potential herb-drug interactions. Ginger is also more likely to irritate the stomach at doses higher than 6 grams per day.

Pregnancy-induced nausea and vomiting

Pregnancy-induced nausea and vomiting (commonly referred to as morning sickness) is a common complaint during the first trimester—affecting up to 80 percent of pregnant women.

A randomized, double-blind, placebo-controlled study of 120 pregnant woman experiencing morning sickness published in the April 2003 issue of Australian & New Zealand Journal of Obstetrics & Gynaecology found that there was significantly less nausea in women taking ginger. Half of the women in this study were randomized to take 125 mg of ginger extract and half to take a placebo four times a day for four days. This study is important because it demonstrates that ginger is safe for pregnant women. Follow-up with participants revealed normal ranges of birth weight, gestational age and congenital abnormalities.

A literature review published in the Annals of Pharmacotherapy in October 2005 found ginger to be a low-risk and effective treatment for nausea and vomiting, suggesting that it could be considered for pregnant women who are experiencing nausea and vomiting but not responding to the first line of treatment. A systemic review of double-blind, randomized, controlled trials published just a month later in Obstetrics & Gynecology found four out of the six trials examined demonstrated ginger was more effective in reducing nausea compared to placebo. There are no known significant side effects or adverse pregnancy outcomes seen with ginger supplementation.

Chemotherapy-induced nausea 

Nausea and vomiting are common side effects of chemotherapy, and numerous prescription drugs are available to help treat and prevent them. Many cancer patients, however, also seek alternative therapies.

A randomized, placebo-controlled, double-blind trial of ginger for chemotherapy-induced nausea published in 2009 in the Journal of Clinical Oncology found that the use of 1/2 to 1 gram of ginger daily significantly reduced symptoms of nausea. This study, which included a total of 644 cancer patients with diagnoses such as breast cancer, alimentary cancer and lung cancer, found that the patients using ginger had a steady decrease in nausea over a 24-hour period.

Postoperative nausea

Nausea is one of the most common side effects of surgical procedures and can lead to poor wound healing, esophageal tears, dehydration, fatigue, hernia and increased healthcare costs due to prolonged hospital stays. Ginger could be a beneficial and inexpensive medication before surgery to prevent nausea.

A meta-analysis published in the American Journal of Obstetrics & Gynecology analyzed five randomized, double-blind, placebo-controlled trials to determine the effects of ginger on post-op nausea and vomiting in patients who had undergone gynecological or lower extremity surgery. The results demonstrated that a fixed dose of at least 1 gram of ginger is more effective than a placebo for the prevention of post-op nausea and vomiting. The only side effect reported was abdominal discomfort. 

A hard pill to swallow

Ginger pills and tinctures might be hard to swallow in the face of gastrointestinal distress, so other forms, such as cookies, crackers and teas, can help. And remember, a well-balanced diet consisting of small, frequent meals and bland foods can also help alleviate nausea and vomiting. As with any nutritional supplement or herb, talk to your healthcare provider before taking ginger.