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Medicine guide

Metformin Er 500 Mg

500 mg · Tablet

  • Prescription only
  • Biguanide
Active substance
Metformin Er 500 Mg
Made by
Quallent Pharmaceuticals Health LLC

Quoted from the official source. Not yet reviewed by Mediclarum — the leaflet in your pack is authoritative.

At a glance

Quoted from the official label · 2025-12-04

What it is

Biguanide

Used for
  • Metformin hydrochloride extended-release tablets are indicated as an adjunct to diet and exercise to improve glycemic control in patients with type 2 diabetes mellitus.
The label’s usual adult dose

Starting dose: 500 mg orally once daily with the evening meal ( 2.1 )

Increase the dose in increments of 500 mg weekly, up to a maximum of 2000 mg once daily with the evening meals ( 2.1 )

Full directions ↓
Serious warning

LACTIC ACIDOSIS Postmarketing cases of metformin-associated lactic acidosis have resulted in death, hypothermia, hypotension, and resistant bradyarrhythmias. The onset of metformin­-associated lactic acidosis is often subtle, accompanied only by…

All warnings ↓
Good to know
  • Prescription only
10other products contain Metformin Er 500 Mg — compare makers, forms and strengths

Every line above is selected, not written, from the official label. Nothing is reworded. DailyMed

What it is for

  • Metformin hydrochloride extended-release tablets are indicated as an adjunct to diet and exercise to improve glycemic control in patients with type 2 diabetes mellitus.
  • Metformin hydrochloride extended-release tablets are biguanide indicated as an adjunct to diet and exercise to improve glycemic control in
  • adults with type 2 diabetes mellitus.
  • ( 1 )

From the official label · 2025-12-04 · DailyMed

How it works

From this product’s own US prescribing label.

Metformin is an antihyperglycemic agent which improves glucose tolerance in patients with type 2 diabetes mellitus, lowering both basal and postprandial plasma glucose.

Metformin decreases hepatic glucose production, decreases intestinal absorption of glucose, and improves insulin sensitivity by increasing peripheral glucose uptake and utilization.

Half-life6.2 h
Mostly cleared after≈ 31 hfive half-lives — our arithmetic
How it leaves the body

Intravenous single-dose studies in normal subjects demonstrate that metformin is excreted unchanged in the urine and does not undergo hepatic metabolism (no metabolites have been identified in humans) nor biliary excretion.

With food

Although the extent of metformin absorption (as measured by AUC) from the metformin hydrochloride extended-release tablet increased by approximately 50% when given with food, there was no effect of food on C max and T max of metformin.

Quoted from the prescribing label, sections “Mechanism of Action” and “Pharmacokinetics”. DailyMed · 2025-12-04

Serious warning

The strongest warning the FDA requires. It is printed in a box at the top of the label.

  • WARNING:
  • LACTIC ACIDOSIS Postmarketing cases of metformin-associated lactic acidosis have resulted in death, hypothermia, hypotension, and resistant bradyarrhythmias. The onset of metformin­-associated lactic acidosis is often subtle, accompanied only by nonspecific symptoms such as malaise, myalgias, respiratory distress, somnolence, and abdominal pain. Metformin­-associated lactic acidosis was characterized by elevated blood lactate levels (>5 mmol/Liter), anion gap acidosis (without evidence of ketonuria or ketonemia), an increased lactate/pyruvate ratio; and metformin plasma levels generally >5 mcg/mL [see Warnings and Precautions (5.1)]. Risk factors for metformin-associated lactic acidosis include renal impairment, concomitant use of certain drugs (e.g. carbonic anhydrase inhibitors such as topiramate), age 65 years old or greater, having a radiological study with contrast, surgery and other procedures, hypoxic states (e.g., acute congestive heart failure), excessive alcohol intake, and hepatic impairment. Steps to reduce the risk of and manage metformin-associated lactic acidosis in these high risk groups are provided [see Dosage and Administration (2.3) , (2.7) , Contraindications (4), Warnings and Precautions (5.1)]. If metformin-associated lactic acidosis is suspected, immediately discontinue metformin hydrochloride extended-release tablets and institute general supportive measures in a hospital setting. Prompt hemodialysis is recommended [see Warnings and Precautions (5.1)]. WARNING:
  • LACTIC ACIDOSIS See full prescribing information for complete boxed warning.
  • Postmarketing cases of metformin-associated lactic acidosis have resulted in death, hypothermia, hypotension, and resistant bradyarrhythmias. Symptoms included malaise, myalgias, respiratory distress, somnolence, and abdominal pain. Laboratory abnormalities included elevated blood lactate levels, anion gap acidosis, increased lactate/pyruvate ratio; and metformin plasma levels generally >5 mcg/mL. (5.1)
  • Risk factors include renal impairment, concomitant use of certain drugs, age >65 years old, radiological studies with contrast, surgery and other procedures, hypoxic states, excessive alcohol intake, and hepatic impairment. Steps to reduce the risk of and manage metformin­ associated lactic acidosis in these high risk groups are provided in the Full Prescribing Information. (5.1)
  • If lactic acidosis is suspected, discontinue metformin hydrochloride extended-release tablets and institute general supportive measures in a hospital setting. Prompt hemodialysis is recommended. (5.1)

Quoted from the official label, section “Boxed Warning”.

Do not take it if

  • Metformin hydrochloride extended-release tablets are contraindicated in patients with:
  • Severe renal impairment (eGFR below 30mL/min/1.73m 2 ) [see Warnings and Precautions (5.1)]. Hypersensitivity to metformin. Acute or chronic metabolic acidosis, including diabetic ketoacidosis, with or without coma.
  • Severe renal impairment (eGFR below 30 mL/min/1.73 m 2 ) ( 4 , 5.1)
  • Hypersensitivity to metformin (4)
  • Acute or chronic metabolic acidosis, including diabetic ketoacidosis, with or without coma. ( 4 )

Quoted from the official label, section “Contraindications”.

How to take it

These directions are for this exact strength and form. Another one is different.

  • Adult Dosage for Metformin Hydrochloride Extended-Release Tablets :
  • Swallow metformin hydrochloride extended-release tablets whole and never crush, cut or chew ( 2.1 )
  • Starting dose: 500 mg orally once daily with the evening meal ( 2.1 )
  • Increase the dose in increments of 500 mg weekly, up to a maximum of 2000 mg once daily with the evening meals ( 2.1 )
  • 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 ( 2.1 ) Renal Impairment :
  • Prior to initiation, assess renal function with estimated glomerular filtration rate (eGFR) ( 2.3 ) o
  • Do not use in patients with eGFR below 30 mL/minute/1.73 m 2 ( 2.3 ) o Initiation is not recommended in patients with eGFR between 30 to 45 mL/minute/1.73 m 2 ( 2.3 ) o Assess risk/benefit of continuing if eGFR falls below 45 mL/minute/1.73 m 2 ( 2.3 ) o Discontinue if eGFR falls below 30 mL/minute/1.73 m 2 ( 2.3 ) Discontinuation for Iodinated Contrast Imaging Procedures :
  • Metformin hydrochloride extended-release tablets may need to be discontinued at time of, or prior to, iodinated contrast imaging procedures ( 2.4 ) 2.1 Adult Dosage Metformin Hydrochloride Extended-Release Tablets
  • Swallow metformin hydrochloride extended-release tablets whole and never crush, cut or chew.
  • The recommended starting dose of metformin hydrochloride extended-release tablets are 500 mg orally once daily with the evening meal.
  • Increase the dose in increments of 500 mg weekly on the basis of glycemic control and tolerability, up to a maximum of 2000 mg once daily with the evening meal.
  • If glycemic control is not achieved with metformin hydrochloride extended-release tablets 2000 mg once daily, consider a trial of metformin hydrochloride extended-release tablets 1000 mg twice daily. If higher doses are required, switch to metformin hydrochloride tablets at total daily doses up to 2550 mg administered in divided daily doses, as described above.
  • 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. 2.3 Recommendations for Use in Renal Impairment
  • Assess renal function prior to initiation of metformin hydrochloride extended-release tablets and periodically thereafter.
  • Metformin hydrochloride extended-release tablets are contraindicated in patients with an estimated glomerular filtration rate (eGFR) below 30 mL/minute/1.73 m 2 .
  • Initiation of metformin hydrochloride extended-release tablets in patients with an eGFR between 30 to 45 mL/minute/ 1.73 m 2 is not recommended.
  • In patients taking metformin hydrochloride extended-release tablets whose eGFR later falls below 45 mL/min/1.73 m 2 , assess the benefit risk of continuing therapy.
  • Discontinue metformin hydrochloride extended- release tablets if the patient's eGFR later falls below 30 mL/minute/1.73 m 2 [see Warnings and Precautions (5.1) ]. 2.4 Discontinuation for Iodinated Contrast Imaging Procedure Discontinue metformin hydrochloride extended-release tablets at the time of, or prior to, an iodinated contrast imaging procedure in patients with an eGFR between 30 and 60 mL/min/1.73 m 2 ; in patients with a history of liver disease, alcoholism, or heart failure; or in patients who will be administered intra-arterial iodinated contrast. Re-evaluate eGFR 48 hours after the imaging procedure; restart metformin hydrochloride extended-release tablets if renal function is stable.

Quoted from the official label, section “Dosage & Administration”.

Other warnings

  • 5. WARNINGS AND PRECAUTIONS
  • Lactic Acidosis : See boxed warning. (5.1)
  • Vitamin B 12 Deficiency :
  • Metformin may lower vitamin B 12 levels. Measure hematological parameters annually and vitamin B 12 at 2 to 3 year intervals and manage any abnormalities. (5.2)
  • Hypoglycemia with Concomitant Use with Insulin and Insulin Secretagogues :
  • Increased risk of hypoglycemia when used in combination with insulin and/or an insulin secretagogue. Lower dose of insulin or insulin secretagogue may be required (5.3) 5.1 Lactic Acidosis 5.2 Vitamin B 12 Deficiency In metformin hydrochloride tablets clinical trials of 29-week duration, a decrease to subnormal levels of previously normal serum vitamin B 12 levels was observed in approximately 7% of patients. Such decrease, possibly due to interference with B 12 absorption from the B 12 -intrinsic factor complex, may be associated with anemia but appears to be rapidly reversible with discontinuation of metformin hydrochloride tablets or vitamin B 12 supplementation. Certain individuals (those with inadequate vitamin B 12 or calcium intake or absorption) appear to be predisposed to developing subnormal vitamin B 12 levels. Measure hematologic parameters on an annual basis and vitamin B 12 at 2 to 3 year intervals in patients on metformin hydrochloride extended-release tablets and manage any abnormalities [see Adverse Reactions (6.1) . 5.3 Hypoglycemia with Concomitant Use with Insulin and Insulin Secretagogues Insulin and insulin secretagogues (e.g., sulfonylurea) are known to cause hypoglycemia. Metformin hydrochloride extended-release tablets may increase the risk of hypoglycemia when combined with insulin and/or an insulin secretagogue. Therefore, a lower dose of insulin or insulin secretagogue may be required to minimize the risk of hypoglycemia when used in combination with metformin hydrochloride extended-release tablets [see Drug Interactions (7) ]. 5.4 Macrovascular Outcomes There have been no clinical studies establishing conclusive evidence of macrovascular risk reduction with metformin hydrochloride extended-release tablets.

Quoted from the official label, section “Warnings”.

Pregnancy and breastfeeding

  • Risk Summary Limited data with metformin hydrochloride extended-release tablets in pregnant women are not sufficient to determine a drug-associated risk for major birth defects or miscarriage.
  • Published studies with metformin use during pregnancy have not reported a clear association with metformin and major birth defect or miscarriage risk [see Data ].
  • There are risks to the mother and fetus associated with poorly controlled diabetes mellitus in pregnancy [see Clinical Considerations ].
  • No adverse developmental effects were observed when metformin was administered to pregnant Sprague Dawley rats and rabbits during the period of organogenesis at doses up to 2- and 5-times, respectively, a 2550 mg clinical dose, based on body surface area [see Data ].
  • The estimated background risk of major birth defects is 6 to 10% in women with pre-gestational diabetes mellitus with an HbA1C >7 and has been reported to be as high as 20 to 25% in women with a HbA1C >10.
  • The estimated background risk of miscarriage for the indicated population is unknown.
  • In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.
  • Clinical Considerations Disease-associated maternal and/or embryo/fetal risk Poorly-controlled diabetes mellitus in pregnancy increases the maternal risk for diabetic ketoacidosis, pre-eclampsia, spontaneous abortions, preterm delivery, stillbirth and delivery complications.
  • Poorly controlled diabetes mellitus increases the fetal risk for major birth defects, stillbirth, and macrosomia related morbidity.
  • Data Human Data Published data from post-marketing studies have not reported a clear association with metformin and major birth defects, miscarriage, or adverse maternal or fetal outcomes when metformin was used during pregnancy.
  • However, these studies cannot definitely establish the absence of any metformin-associated risk because of methodological limitations, including small sample size and inconsistent comparator groups.
  • Animal Data Metformin hydrochloride did not adversely affect development outcomes when administered to pregnant rats and rabbits at doses up to 600 mg/kg/day.
  • This represents an exposure of about 2 and 5 times a 2550 mg clinical dose based on body surface area comparisons for rats and rabbits, respectively.
  • Determination of fetal concentrations demonstrated a partial placental barrier to metformin.
  • IN SPECIFIC POPULATIONS
  • Females and Males of Reproductive Potential:
  • Advise premenopausal females of the potential for an unintended pregnancy. (8.3)
  • Geriatric Use: Assess renal function more frequently. (8.5)
  • Hepatic Impairment:
  • Avoid use in patients with hepatic impairment. (8.7) 8.1 Pregnancy Risk Summary Limited data with metformin hydrochloride extended-release tablets in pregnant women are not sufficient to determine a drug-associated risk for major birth defects or miscarriage. Published studies with metformin use during pregnancy have not reported a clear association with metformin and major birth defect or miscarriage risk [see Data ]. There are risks to the mother and fetus associated with poorly controlled diabetes mellitus in pregnancy [see Clinical Considerations ]. No adverse developmental effects were observed when metformin was administered to pregnant Sprague Dawley rats and rabbits during the period of organogenesis at doses up to 2- and 5-times, respectively, a 2550 mg clinical dose, based on body surface area [see Data ]. The estimated background risk of major birth defects is 6 to 10% in women with pre-gestational diabetes mellitus with an HbA1C >7 and has been reported to be as high as 20 to 25% in women with a HbA1C >10. The estimated background risk of miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Clinical Considerations Disease-associated maternal and/or embryo/fetal risk Poorly-controlled diabetes mellitus in pregnancy increases the maternal risk for diabetic ketoacidosis, pre-eclampsia, spontaneous abortions, preterm delivery, stillbirth and delivery complications. Poorly controlled diabetes mellitus increases the fetal risk for major birth defects, stillbirth, and macrosomia related morbidity. Data Human Data Published data from post-marketing studies have not reported a clear association with metformin and major birth defects, miscarriage, or adverse maternal or fetal outcomes when metformin was used during pregnancy. However, these studies cannot definitely establish the absence of any metformin-associated risk because of methodological limitations, including small sample size and inconsistent comparator groups. Animal Data Metformin hydrochloride did not adversely affect development outcomes when administered to pregnant rats and rabbits at doses up to 600 mg/kg/day. This represents an exposure of about 2 and 5 times a 2550 mg clinical dose based on body surface area comparisons for rats and rabbits, respectively. 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 ]. 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. Therefore, the developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for metformin hydrochloride extended-release tablets and any potential adverse effects on the breastfed child from metformin hydrochloride extended-release tablets or from the underlying maternal condition. Data Published clinical lactation studies report that metformin is present in human milk which resulted in infant doses approximately 0.11% to 1% of the maternal weight-adjusted dosage and a milk/plasma ratio ranging between 0.13 and 1. However, the studies were not designed to definitely establish the risk of use of metformin during lactation because of small sample size and limited adverse event data collected in infants. 8.3 Females and Males of Reproductive Potential Discuss the potential for unintended pregnancy with premenopausal women as therapy with metformin hydrochloride extended-release tablets may result in ovulation in some anovulatory women. 8.4 Pediatric Use Metformin Hydrochloride Extended-Release Tablets Safety and effectiveness of metformin hydrochloride extended-release tablets in pediatric patients have not been established. 8.5 Geriatric Use Controlled clinical studies of metformin hydrochloride extended-release tablets did not include sufficient numbers of elderly patients to determine whether they respond differently from younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy and the higher risk of lactic acidosis. Assess renal function more frequently in elderly patients [see Warnings and Precautions (5.1) ]. 8.6 Renal Impairment Metformin is substantially excreted by the kidney, and the risk of metformin accumulation and lactic acidosis increases with the degree of renal impairment. Metformin hydrochloride extended-release tablets are 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)]. 8.7 Hepatic Impairment Use of metformin in patients with hepatic impairment has been associated with some cases of lactic acidosis. Metformin hydrochloride extended-release tablets are not recommended in patients with hepatic impairment. [see Warnings and Precautions (5.1)].

Quoted from the official label, section “OTC — Pregnancy or Breast Feeding”.

Other medicines

  • Table 3 presents clinically significant drug interactions with metformin hydrochloride extended-release tablets. Table 3:
  • Clinically Significant Drug Interactions with Metformin Hydrochloride Extended-Release Tablets Carbonic Anhydrase Inhibitors Clinical Impact:
  • Carbonic anhydrase inhibitors frequently cause a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. Concomitant use of these drugs with metformin hydrochloride extended-release tablets may increase the risk for lactic acidosis. Intervention:
  • Consider more frequent monitoring of these patients. Examples:
  • Topiramate, zonisamide, acetazolamide or dichlorphenamide. Drugs that Reduce Metformin Hydrochloride Extended-Release Tablets Clearance Clinical Impact:
  • Concomitant use of drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2] / multidrug and toxin extrusion [MATE] inhibitors) could increase systemic exposure to metformin and may increase the risk for lactic acidosis [ see Clinical Pharmacology (12.3)]. Intervention:
  • Consider the benefits and risks of concomitant use with metformin hydrochloride extended-release tablets. Examples:
  • Ranolazine, vandetanib, dolutegravir, and cimetidine. Alcohol Clinical Impact:
  • Alcohol is known to potentiate the effect of metformin on lactate metabolism. Intervention:
  • Warn patients against excessive alcohol intake while receiving metformin hydrochloride extended-release tablets. Insulin Secretagogues or Insulin Clinical Impact:
  • Coadministration of metformin hydrochloride extended-release tablets with an insulin secretagogue (e.g., sulfonylurea) or insulin may increase the risk of hypoglycemia. Intervention:
  • Patients receiving an insulin secretagogue or insulin may require lower doses of the insulin secretagogue or insulin. Drugs Affecting Glycemic Control Clinical Impact:
  • Certain drugs tend to produce hyperglycemia and may lead to loss of glycemic control. Intervention:
  • When such drugs are administered to a patient receiving metformin hydrochloride extended-release tablets, observe the patient closely for loss of blood glucose control. When such drugs are withdrawn from a patient receiving metformin hydrochloride extended-release tablets, observe the patient closely for hypoglycemia. Examples:
  • Thiazides and other diuretics, corticosteroids, phenothiazines, thyroid products, estrogens, oral contraceptives, phenytoin, nicotinic acid, sympathomimetics, calcium channel blockers, and isoniazid.
  • Carbonic anhydrase inhibitors may increase risk of lactic acidosis. Consider more frequent monitoring (7)
  • Drugs that reduce metformin clearance (such as ranolazine, vandetanib, dolutegravir, and cimetidine) may increase the accumulation of metformin. Consider the benefits and risks of concomitant use (7)
  • Alcohol can potentiate the effect of metformin on lactate metabolism. Warn patients against excessive alcohol intake ( 7 )

Quoted from the official label, section “Drug Interactions”.

If you take too much

In an emergency, call your local emergency number or a poison control centre.

  • Overdose of metformin hydrochloride has occurred, including ingestion of amounts greater than 50 grams.
  • Hypoglycemia was reported in approximately 10% of cases, but no causal association with metformin has been established.
  • Lactic acidosis has been reported in approximately 32% of metformin overdose cases [see Warnings and Precautions (5.1)] .
  • Metformin is dialyzable with a clearance of up to 170 mL/min under good hemodynamic conditions.
  • Therefore, hemodialysis may be useful for removal of accumulated drug from patients in whom metformin overdosage is suspected.

Quoted from the official label, section “Overdosage”.

Use in children

Metformin Hydrochloride Extended-Release Tablets Safety and effectiveness of metformin hydrochloride extended-release tablets in pediatric patients have not been established.

Quoted from the official label, section “Pediatric Use”.

Use in older people

  • Controlled clinical studies of metformin hydrochloride extended-release tablets did not include sufficient numbers of elderly patients to determine whether they respond differently from younger patients.
  • In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy and the higher risk of lactic acidosis.
  • Assess renal function more frequently in elderly patients [see Warnings and Precautions (5.1) ].

Quoted from the official label, section “Geriatric Use”.

Side effects

  • The following adverse reactions are also discussed elsewhere in the labeling:
  • Lactic Acidosis [see Boxed Warning and Warnings and Precautions (5.1) ] Vitamin B 12 Deficiency [see Warnings and Precautions (5.2) ] Hypoglycemia [see Warnings and Precautions (5.3) ] For metformin hydrochloride extended-release tablets, the most common adverse reactions (>5.0%) are diarrhea, nausea/vomiting, flatulence, asthenia, indigestion, abdominal discomfort, and headache.
  • (6.1) To report SUSPECTED ADVERSE REACTIONS, Quallent Pharmaceuticals Health LLC at 1-877-605-7243 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch
  • 6.1 Clinical Studies Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
  • Metformin Hydrochloride Extended-Release Tablets In placebo-controlled trials, 781 patients were administered metformin hydrochloride extended-release tablets.
  • Adverse reactions reported in greater than 5% of the metformin hydrochloride extended release tablets patients, and that were more common in metformin hydrochloride extended-release tablets-than placebo-treated patients, are listed in Table 2.
  • Table 2:
  • Adverse Reactions from Clinical Trials of Metformin Hydrochloride Extended-Release Tablets Occurring >5% and More Common than Placebo in Patients with Type 2 Diabetes Mellitus Metformin Hydrochloride Extended-Release Tablets (n=781) Placebo (n=195) Diarrhea 10% 3% Nausea/Vomiting 7% 2% Diarrhea led to discontinuation of metformin hydrochloride extended-release tablets in 0.6% of patients.
  • Additionally, the following adverse reactions were reported in ≥1.0% to ≤5.0% of metformin hydrochloride extended-release tablets patients and were more commonly reported with metformin hydrochloride extended-release tablets than placebo:
  • abdominal pain, constipation, distention abdomen, dyspepsia/heartburn, flatulence, dizziness, headache, upper respiratory infection, taste disturbance.
  • 6.2 Postmarketing Experience The following adverse reactions have been identified during post approval use of metformin.
  • Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
  • Cholestatic, hepatocellular, and mixed hepatocellular liver injury have been reported with postmarketing use of metformin.

Quoted from the official label, section “Adverse Reactions”.

What to discuss with your doctor

  • Advise the patient to read the FDA-approved patient labeling (Patient Information).
  • Lactic Acidosis:
  • Explain the risks of lactic acidosis, its symptoms, and conditions that predispose to its development.
  • Advise patients to discontinue metformin hydrochloride extended-release tablets immediately and to promptly notify their healthcare provider if unexplained hyperventilation, myalgias, malaise, unusual somnolence or other nonspecific symptoms occur.
  • Counsel patients against excessive alcohol intake and inform patients about importance of regular testing of renal function while receiving metformin hydrochloride extended-release tablets.
  • Instruct patients to inform their doctor that they are taking metformin hydrochloride extended-release tablets prior to any surgical or radiological procedure, as temporary discontinuation may be required [see Warnings and Precautions (5.1) ].
  • Hypoglycemia Inform patients that hypoglycemia may occur when metformin hydrochloride extended-release tablets are coadministered with oral sulfonylureas and insulin.
  • Explain to patients receiving concomitant therapy the risks of hypoglycemia, its symptoms and treatment, and conditions that predispose to its development [see Warnings and Precautions (5.3) ].
  • Vitamin B12 Deficiency:
  • Inform patients about importance of regular hematological parameters while receiving metformin hydrochloride extended-release tablets [see Warnings and Precautions (5.2) ].
  • Females of Reproductive Age:
  • Inform females that treatment with metformin hydrochloride extended-release tablets may result in ovulation in some premenopausal anovulatory women which may lead to unintended pregnancy [see Use in Specific Populations (8.3) ].
  • Metformin Hydrochloride Extended-Release Tablets Administration Information:
  • Inform patients that metformin hydrochloride extended-release tablets must be swallowed whole and not crushed, cut, or chewed, and that the inactive ingredients may occasionally be eliminated in the feces as a soft mass that may resemble the original tablet.
  • Dispense with Patient Information is also available at:
  • https://www.quallentpharmaceuticals.com Manufactured by:
  • Granules India Limited Hyderabad-500 081, India MADE IN INDIA Manufactured for:
  • Quallent Pharmaceuticals Health LLC Grand Cayman, Cayman Islands Revision date:
  • 03/2023

Quoted from the official label, section “Patient Counseling Information”.

Strengths and forms

  • FORMS AND STRENGTHS Metformin hydrochloride extended-release tablets are available as:
  • Extended-release tablets:
  • 500 mg White to off-white uncoated, modified capsule shaped tablets debossed with "G7" on one side and plain on other side.
  • Extended-release tablets:
  • 750 mg White to off white uncoated, modified capsule shaped tablets debossed with "G8" on one side and plain on other side. Metformin Hydrochloride Extended-Release Tablets:
  • 500 mg and 750 mg ( 3 )

Quoted from the official label, section “Dosage Forms & Strengths”.

What it looks like and how it is packed

  • 16.1 How Supplied Table 13:
  • Metformin Hydrochloride Extended-Release Tablets, USP Available Strengths, Units, and Appearance Metformin Hydrochloride Extended-Release Tablets, USP 500 mg Bottles of 1000 NDC 82009-117-10 White to off white uncoated, modified capsule shaped tablets debossed with “G7” on one side and plain on other side. 750 mg Bottles of 100 NDC 82009-118-01 White to off white uncoated modified capsule shaped tablets dedossed with “G8” on one side and plain on other side.
  • Storage
  • Store at 20° to 25°C (68° to 77°F); excursions permitted within 15° to 30°C (59° to 86°F). [See USP Controlled Room Temperature.] Dispense in light-resistant container.

Quoted from the official label, section “How Supplied”.

What is in it

  • Metformin hydrochloride extended-release tablets, USP contain the antihyperglycemic agent metformin, which is a biguanide, in the form of monohydrochloride.
  • The chemical name of metformin hydrochloride is N,N -dimethylimidodicarbonimidic diamide hydrochloride .
  • The structural formula is as shown below:
  • Metformin hydrochloride, USP is a white to off-white crystalline compound with a molecular formula of C 4 H 11 N 5 .HCl and a molecular weight of 165.62.
  • Metformin hydrochloride is freely soluble in water, slightly soluble in ethanol, practically insoluble in acetone and in methylene chloride.
  • The pKa of metformin is 12.4.
  • The pH of a 1% aqueous solution of metformin hydrochloride is 6.35.
  • Metformin hydrochloride extended-release tablets, USP contains 500 mg or 750 mg of metformin hydrochloride, which is equivalent to 389.93 mg, 584.90 mg metformin base, respectively.
  • Metformin hydrochloride extended-release tablets USP, 500 mg tablets contain the inactive ingredients hypromellose, magnesium stearate, and polyvinyl pyrrolidone Metformin hydrochloride extended-release tablets USP, 750 mg tablets contain the inactive ingredients hypromellose, magnesium stearate, and polyvinyl pyrrolidone Meets USP Dissolution Test 10 metfor-structure

Quoted from the official label, section “Description”.

Ingredients people check for

Lactose, gluten, dyes, sugars and other ingredients that matter with an allergy, intolerance or diet — as this product’s FDA label lists them.

This label’s list of inactive ingredients names none of: lactose, wheat or gluten, colour dyes, sugars, sugar alcohols, alcohol (ethanol), aspartame (phenylalanine), gelatin, peanut oil, soy, parabens, sulfites, titanium dioxide.

Quoted from the FDA label. A label that does not name an ingredient is not a guarantee that the product is free of it, and formulations change. With an allergy, check the pack and ask a pharmacist.

Every version of this medicine (11)

The same active substance, strength and kind of form, from every company that sells it — with what each label lists.

Showing 11 of 11

Details

Made byQuallent Pharmaceuticals Health LLC
Active substanceMetformin Er 500 Mg
Used inDigestion, stomach, diabetes and nutrition
Strength500 mg
FormTablet
RouteOral
Packs1000 TABLET in 1 BOTTLE
NDC82009-117

Source: NDC Directory · 2026-09-13 · not reviewed by a clinician

Source: US Food and Drug Administration, NDC Directory. Reuse terms: US government work (FDA).

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Other strengths and forms

2 products are sold under this name. Grouped by form; a number on a strength means several companies make it.

  • Tablet2 products
    • 500 mg2

      500 mg · 2 companies

Same active substance

These contain the same substance. That does not mean one can replace another — ask a pharmacist.

Metformin500 mgPrescription onlyTablet A-S Medication Solutions · Metformin Er 500 MgMetformin500 mgPrescription onlyTablet, Extended Release A-S Medication Solutions · Metformin Er 500 MgMetformin500 mgPrescription onlyTablet, Extended Release Coupler LLC · Metformin Er 500 MgMetformin500 mgPrescription onlyTablet, Extended Release Legacy Pharmaceutical Packaging, LLC · Metformin Er 500 MgMetformin500 mgPrescription onlyTablet, Extended Release Granules Pharmaceuticals Inc. · Metformin Er 500 MgMetformin500 mgPrescription onlyTablet, Extended Release REMEDYREPACK INC. · Metformin Er 500 Mg

See every product with Metformin Er 500 Mg