How Kwells Travel Sickness Tablets Work Kwells contains the active ingredient Hyoscine. Hyoscine works to prevent the conflicting nerve messages from reaching the brain which causes the nausea. How To Use Kwells Travel Sickness Tablets It is recommended to take Kwells about 30 minutes prior to travel for the most effective result but they can be taken once symptoms appear. Adults; One tablet should be taken every 6 hours if needed. Do not exceed the recommended dose of 3 tablets in 24 hours. Children over 10 years; Half a tablet should be taken every 6 hours If required. Do not give more than 3 tablets in 24 hours. Not recommended for children under the age of 10. Kwells should not be taken if you are taking medication for glaucoma, antidepressants or if you are allergic to the active ingredient.