Medically reviewed by Jessica Swirble, PharmD
Last updated on 7/3/2024

Drug Information | Side Effects | Use & Dosage | Request a Prescription

The use of metformin ER can lead to various side effects in some individuals.

Common mild side effects of metformin ER use include:

• Diarrhea
  
• Gas
  
• Bloating
  
• Nausea
  
• Vomiting
  
• Upset stomach
  
• Indigestion
  
• Weakness
  
• Headache
  
  

More severe side effects include:

• Hypoglycemia (low blood sugar)- dizziness, fatigue, headache, lightheaded, sweating, shaking
  
• Lactic acidosis (lactic acid buildup in the bloodstream)- low blood pressure, trouble breathing, extreme tiredness, muscle pain, severe abdominal pain
  
• Chest pain
  
• Vitamin B12 deficiency
  
  

If you experience any severe or concerning side effects while taking metformin ER, contact your healthcare provider right away.

Tell your healthcare provider about any existing medical conditions, allergies, or other medications you are taking before starting treatment with metformin ER. This includes prescription drugs, over-the-counter medications, and dietary supplements, as they may interact with metformin ER.

Tell your provider if you are taking these medications or supplements:

• Other diabetes medications
  
• Diuretics
  
• Corticosteroids
  
• Blood pressure medications
  
• Antipsychotic medications
  
• Hormonal contraceptives
  
• Thyroid medications
  
• Seizure medications
  
• Ranolazine
  
• Tivicay
  
• Cimetidine
  
• Anticoagulants or antiplatelet drugs
  
• Alcohol or medications containing alcohol
  
  

You should also mention medical conditions such as:

• Being over 65 years of age
  
• History of heart attacks or heart disease
  
• History of stroke
  
• History of diabetic ketoacidosis
  
• History of liver or kidney disease
  
  

If you are pregnant, planning to become pregnant, or breastfeeding, discuss the potential risks and benefits of using metformin ER with your healthcare provider.

Take metformin ER exactly as prescribed by your healthcare provider. Do not exceed the recommended dose or duration of treatment.

Metformin ER should be taken with a meal.

Your provider may prescribe metformin ER in conjunction with a reduced-calorie diet and increased physical activity to regulate blood sugar levels.

In case of a metformin ER overdose, seek medical attention immediately. Symptoms of overdose may include severe tiredness, weakness, slow heart rate, severe dizziness, or fainting. If you suspect an overdose, contact the poison control helpline at 1-800-222-1222 or call emergency services.