Metformin Vs. Wegovy: Drug Comparison

Metformin is an oral medication commonly prescribed to manage blood sugar levels in individuals with type 2 diabetes. It works by decreasing glucose production in the liver, improving the body's sensitivity to insulin, and reducing the amount of sugar absorbed by the intestines. Metformin is often used as a first-line treatment due to its efficacy, safety profile, and additional benefits, such as weight stabilization and low risk of low blood sugar. Common side effects include gastrointestinal issues like nausea, diarrhea, and abdominal discomfort.

Wegovy^® (semaglutide) is an injectable medication approved for chronic weight management in adults with obesity or overweight with at least one weight-related condition, such as hypertension, type 2 diabetes, or high cholesterol. It works by mimicking the hormone glucagon-like peptide-1 (GLP-1), which regulates appetite and food intake, leading to reduced calorie consumption and significant weight loss. Wegovy is administered once weekly and is intended to be used in conjunction with a reduced-calorie diet and increased physical activity. Common side effects include nausea, diarrhea, vomiting, and constipation. It should be used with caution in patients with a history of pancreatitis and is not recommended for use in pregnant or breastfeeding individuals​.

Biguinide

Glucagon-like peptide-1 (GLP-1) receptor agonist

Metformin hydrochloride tablets are 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

Wegovy (semaglutide) is indicated in combination with a reduced calorie diet and increased physical activity:

• To reduce the risk of major adverse cardiovascular events (cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke) in adults with established cardiovascular disease and either obesity or overweight

• To reduce excess body weight and maintain weight reduction long term in:

  • Adults and pediatric patients aged 12 years and older with obesity

  • Adults with overweight in the presence of at least one weight-related comorbid condition

• Typically taken orally once, twice, or three times daily

• Comes in 500 mg, 850 mg, and 1,000 mg tablets

• Typically taken as an injection once weekly

• Comes in single-dose pens that deliver 0.25 mg, 0.5 mg, 1 mg, 1.7 mg, or 2.4 mg per injection

For metformin hydrochloride, the most common adverse reactions (>5%) are:

• Diarrhea

• Nausea/vomiting

• Flatulence

• Weakness

• Indigestion

• Abdominal discomfort

• Headache

Most common adverse reactions (incidence ≥5%) in adults or pediatric patients aged 12 years and older are:

• Nausea

• Diarrhea

• Vomiting

• Constipation

• Abdominal pain

• Headache

• Fatigue

• Indigestion

• Dizziness

• Abdominal distension

• Belching

• Low blood sugar in patients with type 2 diabetes

• Flatulence

• Inflammation of the digestive system

• Gastroesophageal reflux disease (heartburn)

• Inflammation of the nasal cavities and back of the throat

• Severe renal impairment (eGFR below 30 mL/min/1.73 m²)

• Hypersensitivity to metformin

• Acute or chronic metabolic acidosis, including diabetic ketoacidosis, with or without coma

• Drug interactions: Carbonic anhydrase inhibitors, drugs that reduce metformin clearance (such as ranolazine, vandetanib, dolutegravir, and cimetidine), alcohol

• Personal or family history of medullary thyroid carcinoma or in patients with multiple endocrine neoplasia syndrome type 2

• Known hypersensitivity to semaglutide or any of the excipients in Wegovy

• Drug interactions: Wegovy delays gastric emptying. May impact absorption of concomitantly administered oral medications

• Lactic acidosis: See Boxed Warning

• Vitamin B12 deficiency: Metformin may lower vitamin B12 levels

• Low blood sugar with concomitant use with insulin and insulin secretagogues

• Females and males of reproductive potential: Potential for an unintended pregnancy

• Acute pancreatitis

• Acute gallbladder disease

• Low blood sugar: Concomitant use with insulin or an insulin secretagogue may increase the risk of low blood sugar, including severe low blood sugar

• Acute kidney injury

• Hypersensitivity reactions

• Diabetic retinopathy complications in patients with type 2 diabetes

• Heart rate increase

• Suicidal behavior and ideation

• Pregnancy: May cause fetal harm. When pregnancy is recognized, discontinue Wegovy

• Females and males of reproductive potential: Discontinue Wegovy at least 2 months before a planned pregnancy because of the long half-life of semaglutide

WARNING: LACTIC ACIDOSIS

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.

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.

If lactic acidosis is suspected, discontinue metformin hydrochloride tablets and institute general supportive measures in a hospital setting. Prompt hemodialysis is recommended.

WARNING: RISK OF THYROID C-CELL TUMORS

In rodents, semaglutide causes thyroid C-cell tumors at clinically relevant exposures. It is unknown whether Wegovy causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans as the human relevance of semaglutide-induced rodent thyroid C-cell tumors has not been determined.

Wegovy is contraindicated in patients with a personal or family history of MTC or in patients with multiple endocrine neoplasia syndrome type 2 (MEN 2). Counsel patients regarding the potential risk of MTC and symptoms of thyroid tumors.

*This information is from the metformin hydrochloride label used by Epic Pharma, LLC. See the Full Prescribing Information for more complete information. Metformin may also be the active ingredient in other medications, and this information may not be accurate for all medications that include the active ingredient metformin.

*This information is from the label for brand name Wegovy^®. See the Full Prescribing Information for more complete information. Semaglutide, the active ingredient in Wegovy, may also be the active ingredient in other medications, and this information may not be accurate for all medications that include the active ingredient semaglutide.