Yes, Metformin and Glucophage Are the Same Drug
Metformin and Glucophage are identical medications—Glucophage is simply the brand name for metformin hydrochloride. 1
Understanding the Nomenclature
- Metformin is the generic name of the active pharmaceutical ingredient (the biguanide antihyperglycemic agent) 2
- Glucophage is the original brand name under which metformin was marketed when it received FDA approval in the United States 1
- Both contain the same active ingredient: metformin hydrochloride 2
Available Formulations
The confusion sometimes arises because metformin is available in multiple formulations, all containing the same active drug:
- Immediate-release metformin (generic or branded as Glucophage): typically dosed twice daily with meals 3
- Extended-release metformin (generic or branded as Glucophage XR): typically dosed once daily 3
- Both formulations have comparable absorption (AUC) at equivalent total daily doses, though extended-release has approximately 20% lower peak plasma concentrations 2
Clinical Equivalence
When prescribed at equivalent doses, generic metformin and brand-name Glucophage are therapeutically interchangeable. 2
- The mechanism of action is identical: decreasing hepatic glucose production, reducing intestinal glucose absorption, and improving insulin sensitivity 2
- Clinical efficacy is the same: both reduce A1C by approximately 1.0-1.5% as monotherapy 3
- Side effect profiles are identical: gastrointestinal symptoms (bloating, diarrhea, nausea) and potential vitamin B12 deficiency with long-term use 3
- Safety considerations are the same: contraindicated when eGFR <30 mL/min/1.73 m², requires dose reduction when eGFR 30-45 mL/min/1.73 m² 3, 4
Practical Prescribing Considerations
- Prescriptions can be written for either "metformin" (generic) or "Glucophage" (brand), and pharmacies will typically dispense the generic unless "dispense as written" is specified 1
- The extended-release formulation (whether generic or Glucophage XR) may have better gastrointestinal tolerability than immediate-release, with one study showing reduced GI adverse events (26.34% vs. 11.71%, p=0.0006) when patients switched from immediate-release to extended-release 5
- Maximum recommended daily dose is 2550 mg regardless of formulation or brand name 4, 2
The choice between generic metformin and brand-name Glucophage is purely a matter of cost and patient/prescriber preference, not clinical efficacy or safety. 1