Yes, dry mouth is a possible side effect of the medication metformin. It is not a common side effect, and the exact mechanisms are not well understood. If you have recently started taking metformin and are experiencing dry mouth, it is recommended to wait a few more days to see if the symptom improves on its own. In the meantime, you can try drinking small sips of water or sugar-free drinks, sucking on ice to soothe discomfort and stay hydrated, and avoiding dehydrating beverages like caffeine and alcohol. Avoid mouthwashes containing alcohol as well. If you have any further questions, feel free to reach out for more information.