Is metformin approved for weight loss?

No. The FDA label covers glycaemic control in type 2 diabetes. Any use for weight is outside the approved indications, and this page does not describe what such use involves.

Why is metformin in a weight loss category then?

Because people look for it here. Leaving it out would not answer the question; stating plainly what the label does and does not cover does. Every page in this category marks whether the medication carries an approval for weight management.

Weight loss

Metformin hydrochloride

Biguanide

Metformin hydrochloride: Type 2 diabetesnot weight loss

Not FDA approved for weight lossGeneric availablePrescription only

Each stripe is one section of the label, each division in a stripe one entry in that section. The red bar marks a boxed warning.

Reference information, not medical advice

This page is a reference, not medical advice. It reports what the FDA-approved label states and links to that label. It does not tell anyone what to take, and it cannot replace a conversation with a doctor or pharmacist who knows the person's history.

Metformin is a first-line medication for type 2 diabetes and one of the most widely prescribed medicines in the world. It is often mentioned in discussions of weight, but its FDA label does not list weight loss among the approved uses, and no metformin product has been approved for it.

WARNING: LACTIC ACIDOSIS

In the Metformin hydrochloride label

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.

A boxed warning is the most serious warning the FDA requires. This text is reproduced from the label.

Brands and what each one is approved for

One active ingredient can hold several separate FDA approvals. They are different documents with different approved uses, and mixing them up is the most common mistake made about these medications.

Brand	What its label approves	Supply	Label version
Metformin hydrochlorideREMEDYREPACK INC.	Type 2 diabetesNot weight loss	Prescription	19 May 2026

How it works

Written by us

Everything the metformin label says about how the medicine works is about glucose, and the quotation below is the whole of it. Nothing in that description is presented as a route to weight reduction, which matters on this page: metformin comes up in weight discussions constantly, and its own document does not join the two.

Mechanism of action, Metformin hydrochloride 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. With metformin therapy, insulin secretion remains unchanged while fasting insulin levels and day-long plasma insulin response may decrease.

What the FDA approved it for

From the FDA label

The approved uses, as worded in the label.

Metformin hydrochloride tablets is a biguanide indicated as an adjunct to diet and exercise to improve glycemic control in adults and pediatric patients 10 years of age and older with type 2 diabetes mellitus.

Forms and strengths

From the FDA label

The presentations and strengths listed in the label.

Metformin Hydrochloride Tablets USP, 500 mg: White, biconvex, circular shaped film coated tablets with 'A' debossed on one side and '12' debossed on the other side Metformin hydrochloride tablets:...

How the label says it is taken

From the FDA label

What the label states about administration. It is not a dosing instruction for any individual.

Adult Dosage for Metformin Hydrochloride Tablets: Starting dose: 500 mg orally twice a day or 850 mg once a day, with meals
Increase the dose in increments of 500 mg weekly or 850 mg every 2 weeks, up to a maximum dose of 2550 mg per day, given in divided doses
Doses above 2000 mg may be better tolerated given 3 times a day with meals
Increase dosage in increments of 500 mg weekly up to a maximum of 2000 mg per day, given in divided doses twice daily
Renal Impairment: Prior to initiation, assess renal function with estimated glomerular filtration rate (eGFR)
Do not use in patients with eGFR below 30 mL/minute/1.73 m 2

Most common adverse reactions

From the FDA label

The adverse reactions the label reports as most common.

most common adverse reactions (>5.0%) are diarrhea, nausea/vomiting, flatulence, asthenia, indigestion, abdominal discomfort, and headache.

Warnings and precautions

From the FDA label

The warnings and precautions section of the label.

Lactic Acidosis: See boxed warning.
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.
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

Contraindications

From the FDA label

Situations in which the label states the medication must not be used.

Metformin hydrochloride tablets are contraindicated in patients with: Severe renal impairment (eGFR below 30 mL/min/1.73 m 2).
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) Hypersensitivity to metformin Acute or chronic metabolic acidosis, including diabetic ketoacidosis, with or without coma.

Drug interactions

From the FDA label

Interactions the label singles out.

Table 3 presents clinically significant drug interactions with metformin hydrochloride.
Table 3: Clinically Significant Drug Interactions with Metformin Hydrochloride 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 may increase the risk for lactic acidosis.
Intervention: Consider more frequent monitoring of these patients.

Pregnancy and breastfeeding

From the FDA label

The opening of the pregnancy section of the label. The full section is longer and is in the source document.

Limited data with metformin hydrochloride 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. There are risks to the mother and fetus associated with poorly controlled diabetes mellitus in pregnancy.

Generic or brand

Written by us

Metformin is available as a generic in immediate-release and extended-release forms and is among the least expensive prescription medicines available.

The FDA label database lists 67 approved generic applications for this ingredient.

What affects the cost

Written by us

Cost is the reason metformin comes up in weight discussions at all: it is inexpensive and long established. That does not change what it is approved for. This site sells nothing and links to no sellers.

What pharmacies pay for it

From CMS pricing data

These are acquisition costs: what pharmacies in the United States pay on average to buy the medication, published weekly by the Centers for Medicare and Medicaid Services. They are not retail prices and not what a person pays at the counter, which depends on insurance, pharmacy and discount programmes. They are useful as an objective floor and for seeing how far a brand sits above its generic.

Measured	Generic
per tablet, capsule or pen	$0.025 (range $0.014 to $14.61, 7606 listings)
per millilitre	$0.421 (range $0.385 to $0.563, 120 listings)

Median of 7726 listings. Effective dates 2025-12-17 to 2026-07-22, file dated 2026-07-29.

Common questions

Written by us

Is metformin approved for weight loss?: No. The FDA label covers glycaemic control in type 2 diabetes. Any use for weight is outside the approved indications, and this page does not describe what such use involves.
Why is metformin in a weight loss category then?: Because people look for it here. Leaving it out would not answer the question; stating plainly what the label does and does not cover does. Every page in this category marks whether the medication carries an approval for weight management.

Other medications under weight loss

Whether each one carries an FDA approval for this use is marked on its page and in this list.

Sources

Every fact above comes from one of these documents. The date is the effective date of the label version this page was built from.

FDA prescribing information for Metformin hydrochloride
REMEDYREPACK INC.. Label version 14, effective 19 May 2026.
Full label on DailyMed Approval record ANDA077095

Page last updated: 16 August 2026

Compiled by the HealthyStudy editorial team from FDA source documents. No medical reviewer is credited on this page, because none reviewed it.