@mwilson270 welcome to Mayo Clinic Connect. All meds have unwanted side affects and Metformin is no different. I’m not aware of changes in frequency of urination being one of them. I know that many people have difficulty adjusting to Metformin for a variety of reasons. As a nearly 50+ years diabetic myself I can say that frequent urination is a distinctive symptom of diabetes. It is the bodies’ attempt to get rid of excessive blood sugar. It is what ultimately leads to kidney problems. As a diabetic do you monitor blood sugar? That would be a simple way to rule out that high blood sugar is behind the frequent urination. As others have suggested it is a great idea to have a visit with your endocrinologist. In the meantime a visit to your primary, a urologist or nephrologist to discuss the frequent urination may be helpful. They can help rule out other causes of frequent urination such as urinary tract infections (kidney, bladder). It is also a good idea to make sure you are well hydrated (unless you hear otherwise from your provider). Keep fluids going earlier in the day to prevent further nighttime interruptions.