Wegovy (Semaglutide): A Detailed Overview

Overview: Wegovy is a high-dose (2.4 mg) injectable form of semaglutide, a glucagon‑like peptide‑1 (GLP‑1) receptor agonist, developed by Novo Nordisk specifically for weight management in adults and adolescents (12 years and older) with obesity or overweight with comorbidities .
Regulatory Approvals:
- In the United States, Wegovy was FDA-approved in June 2021 for long-term weight management.
- In March 2024, the FDA expanded its indication to reduce the risk of major cardiovascular events—including heart attack, stroke, and death—in adults with overweight or obesity who also have established cardiovascular disease .
- Other regions, including the European Union, have also authorized Wegovy for weight management since early 2022.

How It Works: Wegovy mimics the GLP‑1 hormone to regulate appetite, promote satiety, slow gastric emptying, and reduce calorie intake. It also supports insulin release and decreases glucagon production.
Weight Loss Results: In a pivotal clinical trial (STEP program), participants using Wegovy lost ~14.9% of body weight over 68 weeks vs. 2.4% with placebo—a treatment difference of ~12.4 percentage points.

Clinical Trial Data (2024): Wegovy reduced risk of major cardiovascular events by approximately 20% compared to placebo in patients with obesity or overweight plus cardiovascular disease.
Real‑World Evidence (2025): A recent observational study of over 21,000 patients showed that Wegovy cut the incidence of heart attack, stroke, or death by 57% compared to tirzepatide (Lilly’s Zepbound/Mounjaro), another GLP‑1 agent.

Common Side Effects: These include gastrointestinal issues—nausea, vomiting, diarrhea, constipation—and sometimes headache or fatigue.
Boxed Warning: Animal studies (rodents) have shown a risk of thyroid C-cell tumors; while human risk is unknown, this remains a labeled precaution. Wegovy is contraindicated in patients with personal or family history of medullary thyroid carcinoma or MEN2 syndrome.
Rare Adverse Events:
- Vision-related risk: Reports link semaglutide drugs—including Wegovy—to a rare eye condition called non‑arteritic anterior ischemic optic neuropathy (NAION), which led to irreversible vision loss. The risk is estimated to increase by about fourfold in diabetics and sevenfold in obese individuals, though the absolute risk remains very low.
- Neovascular age-related macular degeneration (nAMD): A study found a slightly higher incidence (0.2% vs. 0.1%) among GLP‑1 users in Canada.
- Hair loss: Semaglutide users may have a 52% higher risk of alopecia compared to those using alternative medications like bupropion‑naltrexone.

Usage: Wegovy is used alongside a reduced-calorie diet and increased physical activity—for both weight loss and cardiovascular risk reduction.
Dosing Schedule: It’s administered via weekly subcutaneous injection using a prefilled pen in areas like the abdomen, thigh, upper arm, or buttocks.

Cost & Coverage:
- In the U.S., the list price is around $1,349 per month (2022 data). Insurance coverage varies; Medicare Part D generally does not cover it, and many employer plans offer limited coverage.
- In France, Wegovy was launched in October 2024 at €274–365/month and was not yet reimbursed at the time, limiting access.
Global Supply and Generics:
- Recent regulatory crackdowns have significantly reduced compounding and unregulated versions of semaglutide. As a result, Chinese manufacturers are shifting toward launching legitimate generic versions in regions where patents expire, such as Canada or Brazil.
- In major markets such as Canada, Brazil, and China, semaglutide patents are slated to expire in 2026, potentially opening the door to generics.

Beyond Weight Loss: Some preliminary findings suggest that GLP‑1 agonists like semaglutide may assist users in smoking cessation, possibly by affecting reward pathways in the brain.
Drug Development Landscape: Novo Nordisk is being challenged by emerging multi-targeted therapies (e.g., experimental 4‑in‑1 drugs combining GLP‑1, GIP, glucagon, and PYY) aiming to surpass current treatments in effectiveness and side-effect profile—though these remain in preclinical stages .

Summary Table

Aspect	Key Points
Active Ingredient	Semaglutide (GLP‑1 receptor agonist)
Indications	Weight loss; cardiovascular event risk reduction in obese/overweight individuals
Mechanism	Appetite suppression; slows digestion; promotes satiety
Efficacy	~15% weight loss over ~68 weeks; 20%–57% cardiovascular risk reduction
Common Side Effects	Gastrointestinal symptoms, nausea, headaches
Rare Risks	Thyroid tumors (rodent data), vision issues (NAION, nAMD), possible hair loss
Administration	Weekly subcutaneous injection
Cost & Access	Expensive; limited coverage; generics emerging in select markets
Emerging Research	Smoking cessation, novel multi‑hormone drugs