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Thiazolidinediones (TZDs)

How they work: TZDs activate a protein that regulates genes involved in making and using fats, with the net result of decreasing insulin resistance. Insulin resistance, or the inability of cells in the body to respond appropriately to insulin by removing glucose from the blood, is one of the underlying problems of type 2 diabetes.

Who Uses Them: TZDs are used by people with type 2 diabetes who need increased glucose-lowering beyond what metformin and/or other agents can provide. The usage of TZDs in the US and Europe has dropped significantly in the past few years due to safety concerns.

In-Depth Article: The TZD ClassAn article on the advantages and disadvantages of the TZD drug class.

Approved Drugs:

* Available in the US but not in Europe and some other areas




  • Improved insulin sensitivity

  • Oral, once-daily pills

  • Cheap and generic

  • Good efficacy/A1c reduction

  • Can be combined with other drugs

  • Weight gain

  • Edema (fluid retention)

  • Increased risk of heart failure

  • Increased bone fracture risk


Last updated: February 28, 2018