Hi @rosemariewalters, welcome to Mayo Clinic Connect. You are wise to ask about possible drug interactions when starting a supplement. High doses of D-mannose may cause kidney damage. D-mannose is a form of sugar and may not be recommended for some people, especially people who have diabetes. Always tell your doctor about any supplements you are taking, including natural ones and those bought without a prescription. That way, your doctor can check on any potential side effects or interactions with any medications. A pharmacist is also a great resource for such questions. They can look up the medications you take and make you aware of any possible drug interactions.

Rose-Marie, are frequent urinary tracts infections something you have to deal with?