Recently, the question was asked: "Can diabetes be totally cured? Is there any medicine that will cure diabetes totally?"
You have asked the same questions that everyone else thinks about, and that everyone hopes will have an answer soon. Unfortunately, the concept of "cure" doesn't seem to apply to diabetes.
That's because diabetes isn't a single disease, but a collection of different disorders, some of which are autoimmune, most of which are genetic, and all of which involve either the destruction of the pancreas' ability to make insulin, or the body's ability to use insulin appropriately (or both). Examples of the different types of diabetes that would need different approaches to be cured: type 1 (autoimmune) diabetes, type 2 (insulin-resistant) diabetes, MODY diabetes (which is actually a name covering at least a dozen different monogenetic forms of diabetes), post-surgical diabetes (after pancreatectomy surgery), bronze diabetes (medically called hemochromatosis), chemically-induced diabetes (such as the diabetes induced by Agent Orange) and Cystic Fibrosis-Related Diabetes. Therefore, any cure that eventually might be developed would probably only affect a percentage of the people who have one of the various forms of diabetes, and wouldn't be likely to cure any of the other types of diabetes.
Since diabetes has different causes, it's also no surprise that there's no single medication that can control, let alone cure, all the different forms of diabetes. Giving insulin by injection is probably the closest to a magic bullet to treat the hyperglycemia of all the forms of diabetes, but some of the forms can be readily treated without the hassle of injections and the risk of hypoglycemia and weight gain that come with insulin therapy.
The closest to the idea of a medication to cure diabetes, from my way of thinking, isn't a medication per se, but would be pancreas transplantation - or better still, transplantation of the islet cells of the pancreas. Such transplants have been tried for many years in patients with type 1 diabetes, and occasionally results in the patients remaining off insulin supplementation for long periods of time, but at the price of the patient instead needing to take toxic anti-rejection drugs to decrease the odds that the body will reject the transplant. By the way, there is a rare form of diabetes that can be prevented by transplantation: in patients who are undergoing surgery to remove the pancreas for a condition called chronic pancreatitis, it's possible to autotransplant their islets from the pancreas that's being removed and implant them into the patient, thus preventing diabetes from developing.
I must add another thought for the reader to chew on.
I find it sad that fund-raising organizations have continuously misled people with diabetes into thinking that a cure is "just around the corner." See, for instance, the JDRF's current slogan: "Improving lives. Curing Type 1 Diabetes." JDRF does provide their definition of cure: "Restoring a person's insulin-producing capability and halting or reversing the body's misguided immune attack on the pancreas." But by its wording, their definition could only apply to type 1 diabetes, as type 2 diabetes is not an immune disorder. The ADA also invokes the cure concept in their mission statement: "Our mission is to prevent and cure diabetes and to improve the lives of all people affected by diabetes".
If you don't look closely at both organization's slogans, you might think that a cure already exists and that these organizations are involved in providing the cure. But sadly, the concept of a diabetes cure remains a will-of-the-wisp, a wonderful idea that always remains just out of reach.