Evaluation of the Chemo-preventive Effect of Combined Topical and Systemic Metformin on Oral Leukoplakia

This study is testing whether metformin — a widely used diabetes medication — applied both topically (directly to the mouth lesion as a cream) and taken orally (as a pill) can prevent oral leukoplakia (white patches inside the mouth that can become cancerous) from progressing to cancer. **You may be eligible if...** - You are an adult over 21 years old - You have been diagnosed with oral leukoplakia confirmed by biopsy - Your lesion shows mild to moderate cell changes (dysplasia) - You are willing to sign an informed consent form **You may NOT be eligible if...** - Your lesion shows severe dysplasia (more advanced cell changes) - You have heart, lung, kidney, or liver disease - You already take metformin (e.g., for diabetes or PCOS) - You take medications that interfere with metformin absorption (such as certain acid reflux drugs) - You are allergic to metformin - You are currently taking retinoids, green tea supplements, or other natural product therapies for your lesion - You have other active lesions in your mouth - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.