Mouth sores and infections can be common among people who regularly use methamphetamine. It is important to maintain good oral health, brush and floss your teeth regularly. Drink water or fruit juice or chew gum to keep your mouth moist and to reduce cracks, blisters and clenching. For people who smoke methamphetamine it is important to protect your lips (lip balm will help protect and heal chapped lips), and to use your own equipment and not share it with others.