FDA-approved
Metformin
The low-cost foundation for prediabetes and type 2 diabetes.
KEY EVIDENCE
Diabetes Prevention Program (NEJM 2002)
VIDEO LESSON
How it's taken
• With meals, starting low and increasing over weeks
• Extended-release once daily is often better tolerated
Monitoring
Kidney function at least yearly and vitamin B12 periodically.
Good to know
Metformin alone rarely causes low blood sugar.
AT A GLANCE
Type
Medication
Brand names
Glucophage, extended-release metformin (generic)
Status
FDA-approved
Reviewed by
Farhan Tahir, MD
Is this treatment right for you?
Prescription medicines and procedures need individual medical advice. Dr. Tahir’s team offers consults through Youthful Medicine.
How it works
Metformin lowers glucose production by the liver and improves insulin sensitivity. Its effect on weight is modest.
What the evidence shows
In the Diabetes Prevention Program, metformin reduced progression to diabetes by 31% compared with placebo. It remains a common first medicine in type 2 diabetes.
Side effects & cautions
Stomach upset and diarrhea are common at first; extended-release forms help. Long-term use can lower vitamin B12. Avoid with severe kidney disease.
PRIMARY SOURCE
Knowler WC, et al. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med. 2002
TYPICAL RESULT IN TRIALS
Typically lowers A1c by about 1 percentage point in type 2 diabetes.
PHYSICIAN FIRST
Is this right for you?
Prescription treatments need a review of your history, labs and other medicines. Never start or stop one on your own.