weight-body
What Is GLP-1 Therapy? Ozempic, Wegovy, and Mounjaro Explained
Last reviewed: May 2026 · Haute MD Editorial Team
GLP-1 (glucagon-like peptide-1) receptor agonists are a class of injectable medications that mimic gut hormones involved in hunger and satiety regulation. They slow gastric emptying, reduce appetite signaling, and decrease food intake — producing average body weight loss of 15-17% with semaglutide (Ozempic/Wegovy) and 20-22% with tirzepatide (Mounjaro/Zepbound, which acts on both GLP-1 and GIP receptors). These medications represent the most significant non-surgical advance in obesity treatment in decades.
How GLP-1 medications work
GLP-1 is a hormone produced in the gut after eating that signals fullness to the brain, stimulates insulin release, and slows gastric emptying. People with obesity have impaired GLP-1 signaling — GLP-1 medications restore and amplify this signal. The result is reduced hunger, earlier satiety, decreased food cravings (particularly for high-fat, high-sugar foods), and slower digestion. The brain's "set point" for body weight is reset lower over months of treatment.
The medications compared
Semaglutide (Ozempic 0.5-2mg weekly — approved for T2D; Wegovy 2.4mg weekly — approved for obesity) produces average 15-17% body weight loss in 68 weeks. Tirzepatide (Mounjaro — approved for T2D; Zepbound — approved for obesity) acts on both GLP-1 and GIP receptors, producing 20-22% body weight loss — the highest of any non-surgical treatment currently available. Liraglutide (Saxenda) produces more modest 5-8% weight loss and is less commonly prescribed since weekly injectables became available.
Side effects and what to expect
The most common side effects are gastrointestinal — nausea, vomiting, diarrhea, constipation — most prominent when starting and with each dose increase. Starting at low doses and titrating slowly over months (the standard protocol) significantly reduces GI side effects. Most patients tolerate the medications well by the maintenance dose. Rare but serious risks include pancreatitis and thyroid C-cell tumors (in animal studies; contraindicated in patients with personal or family history of medullary thyroid carcinoma or MEN2).
Frequently Asked Questions
Who qualifies for GLP-1 medications for weight loss?
FDA-approved criteria — BMI 30+ (obesity) or BMI 27+ with at least one weight-related health condition (type 2 diabetes, high blood pressure, high cholesterol, obstructive sleep apnea). Contraindications include personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia type 2 (MEN2).
How much does Wegovy cost and is it covered by insurance?
Wegovy lists at approximately $1,350/month without insurance. Insurance coverage is variable — employer-sponsored plans increasingly cover it; Medicare does not currently cover weight loss medications. Manufacturer savings programs can reduce cost for commercially insured patients.
How long does it take to see results with GLP-1 medications?
Most patients notice appetite reduction within the first 1-2 weeks. Measurable weight loss typically begins by week 4-8. Maximum weight loss occurs at 12-16 months in most clinical protocols. Weight loss is gradual — approximately 1-2 lbs per week.
Can I take GLP-1 medications if I don't have diabetes?
Yes. Wegovy (semaglutide 2.4mg) and Zepbound (tirzepatide) are FDA-approved specifically for chronic weight management in adults without diabetes who meet BMI criteria. Ozempic and Mounjaro are approved for type 2 diabetes but are frequently prescribed off-label for weight loss.
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