All about Metformin


What is Metformin?

Metformin is one of the most frequently prescribed oral medications for type 2 diabetes treatment. It may be prescribed to the newly diagnosed as the first line of treatment prior to insulin. Metformin is listed under various names, including Metformin XR. 

The drug belongs to the family of biguanides which increase insulin sensitivity and therefore have a beneficial effect in blood glucose management, particularly in insulin resistance. The biguanides started to be used in the 50s. As previously mentioned, it is perhaps the oral drug more prescribed in the world for type 2 diabetes treatment and its use is currently being studied in patients with type 1 diabetes. In 1998 the famous study (UKPDS) demonstrated the effects of metformin. It is currently used in combination with other oral drugs and can be prescribed to be used with insulin.

How does Metformin Work?

These drugs reduce the amount of glucose produced by our body, specifically in our liver and also improves the response that it has to insulin. Remember that in the case of type 2 diabetes, production of insulin is insufficient or does not have an adequate response.

Side effects of Metformin

The side effects are generally gastrointestinal discomfort, including:

  • Nausea
  • Diarrhea
  • Lack of appetite
  • Stomachache
  • Inflammation
  • Flatulence
  • Metallic taste in the mouth, among others

 These symptoms can go away on their own, however, you may want to consider seeing your doctor to receive additional treatment. 

Metformin is not recommended for use in the following cases:

  • If you have any liver or kidney related disease
  • If you will have surgery and you will be fasting
  • If you will have a test done that requires contrast methods


  • Dabex®
  • Fortamet®
  • Glucophage®
  • Glumetza®
  • Riomet®
  • Segluromet®
  • Synjardy®

Combined product trademarks

  • Actoplus Met® 
  • Avandamet® 
  • Invokamet® 
  • Janumet® 
  • Jentadueto® 
  • Kombiglyze® XR 
  • Metaglip® 
  • Prandimet® 
  • Xigduo® XR 

Metformin isn’t the only drug available for people with type 2 diabetes, in fact, there are other drug classes specifically for people with type 2. 


  1. Inzucchi SE: Oral antihyperglycemic for type 2 diabetes. Scientific Review. JAMA 2002;287:360-372. 2.
  2. Roses J, Streets J, Friege F, Lara E, et al. Consenso de prediabetes (Prediabetes consensus). Document about the ALAD’s stance. Rev ALAD 2009; 146-158.

WRITTEN BY Beyond Type 2 Editorial Team, POSTED 02/13/19, UPDATED 07/27/23

This piece was authored collaboratively by the Beyond Type 2 Editorial Team.