Even though glucosamine is technically a type of sugar, it doesn't appear to affect blood sugar levels or insulin sensitivity. Some early research had suggested that glucosamine might worsen insulin resistance, which can contribute to increases in blood sugar in people with type 2 diabetes. But later studies refuted these findings.
Glucosamine is one of the most popular dietary supplements sold in the United States, although study results have been mixed regarding its ability to reduce osteoarthritis pain.
Although glucosamine doesn't appear to affect glucose levels or insulin sensitivity, it can interact with other medications you might be taking — such as warfarin (Coumadin, Jantoven), a blood thinner. As is important with any dietary supplement, talk to your doctor before you add glucosamine to your daily regimen.