Ginger may be useful for the prevention and treatment of mild to moderate cases of motion sickness. A double-blind trial examined the effects of ginger supplements in people who were susceptible to motion sickness. Researchers found that those taking 940 mg of powdered ginger in capsules experienced less motion sickness than those who took dimenhydrinate (Dramamine).¹ Another double-blind trial reported that 1 gram of powdered ginger root, compared with placebo, lessened seasickness by 38% and vomiting by 72% in a group of naval cadets sailing in heavy seas.² Two clinical trials, one with adults and one with children, found that ginger was as effective in treating seasickness as dimenhydrinate but with fewer side effects.^3,4 In one controlled trial, though, neither powdered ginger (500 to 1,000 mg) nor fresh ginger (1,000 mg) provided any protection against motion sickness.⁵ Doctors prescribing ginger for motion sickness recommend 500 mg one hour before travel and then 500 mg every two to four hours as necessary. The study with children used one-half the adult amount.

Ginger’s beneficial effect on motion sickness appears to be related to its action on the gastrointestinal tract rather than on the central nervous system.^6,7

Black horehound(Ballotta nigra, Marrubium nigrum) is sometimes used by herbalists to treat nausea associated with motion sickness.⁸ However, there are no clinical trials to confirm its effectiveness for treating this condition.