Metformin

DRUG INFORMATION

  ADULT
    - Increase the dose in increments of 500 mg weekly or 850 mg every 2 weeks on the
      basis of glycemic control and tolerability, up to a maximum dose of 2550 mg per
      day, given in divided doses.
      Source: US FDA label for metformin (Metformin Hydrochloride), section 'dosage and
      administration', retrieved 2026-08-29
    - Doses above 2000 mg may be better tolerated given 3 times a day with meals.
      Source: US FDA label for metformin (Metformin Hydrochloride), section 'dosage and
      administration', retrieved 2026-08-29
    - The recommended starting dose of metformin hydrochloride extended-release tablets
      is 500 mg orally once daily with the evening meal.
      Source: US FDA label for metformin (Metformin Hydrochloride), section 'dosage and
      administration', retrieved 2026-08-29

  CHILD
    - Metformin Hydrochloride Tablets The safety and effectiveness of metformin
      hydrochloride tablets for the treatment of type 2 diabetes mellitus have been
      established in pediatric patients 10 to 16 years old. Safety and effectiveness of
      metformin hydrochloride tablets have not been established in pediatric patients
      less than 10 years old.
      Source: US FDA label for metformin (Metformin Hydrochloride), section 'pediatric
      use', retrieved 2026-08-29
    - A maximum daily dose of 2000 mg of metformin hydrochloride tablets is recommended.
      [See Dosage and Administration ( 2.2 ) .] Metformin Hydrochloride Extended-Release
      Tablets Safety and effectiveness of metformin hydrochloride extended-release
      tablets in pediatric patients have not been established.
      Source: US FDA label for metformin (Metformin Hydrochloride), section 'pediatric
      use', retrieved 2026-08-29
    - Patients receiving metformin hydrochloride tablets may be switched to metformin
      hydrochloride extended-release tablets once daily at the same total daily dose, up
      to 2000 mg once daily. 2.2 Pediatric Dosage for metformin hydrochloride tablets
      The recommended starting dose of metformin hydrochloride tablets for pediatric
      patients 10 years of age and older is 500 mg orally twice a day, given with meals.
      Source: US FDA label for metformin (Metformin Hydrochloride), section 'dosage and
      administration', retrieved 2026-08-29

  RENAL IMPAIRMENT
    - Increase dosage in increments of 500 mg weekly on the basis of glycemic control
      and tolerability, up to a maximum of 2000 mg per day, given in divided doses twice
      daily. 2.3 Recommendations for Use in Renal Impairment Assess renal function prior
      to initiation of metformin hydrochloride tablets and metformin hydrochloride
      extended-release tablets and periodically thereafter.
      Source: US FDA label for metformin (Metformin Hydrochloride), section 'dosage and
      administration', retrieved 2026-08-29
    - Metformin hydrochloride tablets and metformin hydrochloride extended-release
      tablets is contraindicated in patients with an estimated glomerular filtration
      rate (eGFR) below 30 mL/minute/1.73 m 2 .
      Source: US FDA label for metformin (Metformin Hydrochloride), section 'dosage and
      administration', retrieved 2026-08-29
    - Initiation of metformin hydrochloride tablets and metformin hydrochloride
      extended-release tablets in patients with an eGFR between 30 – 45 mL/minute/1.73 m
      2 is not recommended.
      Source: US FDA label for metformin (Metformin Hydrochloride), section 'dosage and
      administration', retrieved 2026-08-29

  HEPATIC IMPAIRMENT
    - (8.5) Hepatic Impairment: Avoid use in patients with hepatic impairment.
      Source: US FDA label for metformin (Metformin Hydrochloride), section 'use in
      specific populations', retrieved 2026-08-29
    - Metformin hydrochloride tablets and metformin hydrochloride extended-release
      tablets is contraindicated in severe renal impairment, patients with an estimated
      glomerular filtration rate (eGFR) below 30 mL/min/1.73 m 2 [see Dosage and
      Administration ( 2.3 ), Contraindications ( 4 ), Warnings and Precautions ( 5.1 ),
      and Clinical Pharmacology ( 12.3 ) ].
      Source: US FDA label for metformin (Metformin Hydrochloride), section 'use in
      specific populations', retrieved 2026-08-29
    - Metformin hydrochloride tablets and metformin hydrochloride extended-release
      tablets is not recommended in patients with hepatic impairment. [see Warnings and
      Precautions ( 5.1 ) ].
      Source: US FDA label for metformin (Metformin Hydrochloride), section 'use in
      specific populations', retrieved 2026-08-29

  PREGNANCY
    - Risk Summary Limited data with metformin hydrochloride tablets and metformin
      hydrochloride extended-release tablets in pregnant women are not sufficient to
      determine a drug-associated risk for major birth defects or miscarriage.
      Source: US FDA label for metformin (Metformin Hydrochloride), section 'pregnancy',
      retrieved 2026-08-29
    - Published studies with metformin use during pregnancy have not reported a clear
      association with metformin and major birth defect or miscarriage risk [see Data].
      Source: US FDA label for metformin (Metformin Hydrochloride), section 'pregnancy',
      retrieved 2026-08-29
    - There are risks to the mother and fetus associated with poorly controlled diabetes
      mellitus in pregnancy [see Clinical Considerations].
      Source: US FDA label for metformin (Metformin Hydrochloride), section 'pregnancy',
      retrieved 2026-08-29

  BREASTFEEDING
    - Discuss the potential for unintended pregnancy with premenopausal women as therapy
      with metformin hydrochloride tablets and metformin hydrochloride extended-release
      tablets may result in ovulation in some an ovulatory women.
      Source: US FDA label for metformin (Metformin Hydrochloride), section 'nursing
      mothers', retrieved 2026-08-29
    - Determination of fetal concentrations demonstrated a partial placental barrier to
      metformin. 8.2 Lactation Risk Summary Limited published studies report that
      metformin is present in human milk [see Data].
      Source: US FDA label for metformin (Metformin Hydrochloride), section 'use in
      specific populations', retrieved 2026-08-29
    - However, there is insufficient information to determine the effects of metformin
      on the breastfed infant and no available information on the effects of metformin
      on milk production.
      Source: US FDA label for metformin (Metformin Hydrochloride), section 'use in
      specific populations', retrieved 2026-08-29