As of 2015, more research is needed to determine whether or not cinnamon has an effect on diabetes, according to Mayo Clinic. Anyone considering taking cinnamon for diabetes should first talk to a doctor before beginning any supplement plan.
Several 2009 studies suggest that cinnamon has a positive effect on glycemic control, according to Mayo Clinic. One study in particular showed that when taking 500 milligrams of cinnamon twice a day for 90 days, a group's average blood sugar level improved by 7 percent. Another study found that cinnamon lowered blood sugar levels by 24 percent, states WebMD. However, similar studies showed no such effects and research is still ongoing.