GLP-1 Drug Examples & Comparison

From Byetta to Wegovy: a complete guide to GLP-1 medications approved for weight loss and diabetes management.

Updated April 2026 | Medical review in progress
The bottom line: GLP-1 drugs span two decades, from Byetta (2005) to next-gen options like Wegovy and Mounjaro. The newest medications produce stronger weight loss (15–22% of body weight) but cost more and have longer waitlists. First-gen options are cheaper and widely available but deliver modest results (3–8% weight loss).

What Are GLP-1 Drugs?

GLP-1 (glucagon-like peptide-1) medications mimic a natural hormone that regulates blood sugar and appetite. Originally developed for type 2 diabetes, newer formulations are approved specifically for weight loss. The drug family spans nearly 20 years of innovation—from daily injections to once-weekly shots to once-daily oral tablets.

Complete GLP-1 Drug Comparison

This table covers all major GLP-1 medications in the U.S. market, organized by generation and approval status.

Brand Name Active Ingredient Approved For How Taken Typical Weight Loss
Wegovy semaglutide Weight loss (BMI ≥27) Weekly injection 15–22% of body weight
Zepbound tirzepatide Weight loss (BMI ≥27) Weekly injection 17–22% of body weight
Ozempic semaglutide Type 2 diabetes Weekly injection 3–5% (off-label for weight loss)
Mounjaro tirzepatide Type 2 diabetes Weekly injection 4–6% (off-label for weight loss)
Rybelsus semaglutide Type 2 diabetes Daily oral tablet 2–4%
Saxenda liraglutide Weight loss (BMI ≥30) Daily injection 5–8% of body weight
Victoza liraglutide Type 2 diabetes Daily injection 2–4%
Trulicity dulaglutide Type 2 diabetes Weekly injection 1–3%
Byetta exenatide Type 2 diabetes Twice-daily injection 2–4%

Second-Generation Drugs (2021–Present)

The newest GLP-1 medications deliver the strongest weight loss results and are driving the current surge in popularity.

Wegovy (semaglutide) — FDA-approved for weight loss in 2021. Weekly injection. Strongest clinical data shows 15–22% weight loss over 68 weeks. Most commonly prescribed weight-loss drug in the U.S. Long waitlists due to demand.

Zepbound (tirzepatide) — FDA-approved for weight loss in late 2023. Dual-action mechanism (GLP-1 + GIP). Slightly higher weight loss than Wegovy (17–22% in trials). Weekly injection. Newer drug with growing availability.

Ozempic & Mounjaro — Originally approved for type 2 diabetes, these are prescribed off-label for weight loss due to strong efficacy and lower cost than Wegovy/Zepbound. Both weekly injections. Off-label prescribing is legal but requires a doctor's judgment.

The Oral Option: Rybelsus

Rybelsus is the only GLP-1 medication taken by mouth (daily tablet) rather than injection. It's approved for type 2 diabetes only, not weight loss. Weight loss is modest (2–4%), and absorption is finicky—must be taken on an empty stomach 30 minutes before food or drink. Most people prefer injections for better results.

First-Generation Drugs (2005–2020)

These older medications are less potent than newer options but remain available, cheaper, and easier to access. Most are approved for diabetes; weight loss is a secondary benefit.

Saxenda (liraglutide) — FDA-approved for weight loss in 2014. Daily injection. Delivers 5–8% weight loss. Widely available and covered by insurance. Fewer side effects than newer drugs but requires daily dosing instead of weekly.

Victoza & Trulicity — Both approved for diabetes. Liraglutide (Victoza) requires daily injections with modest weight loss (2–4%). Dulaglutide (Trulicity) is weekly with minimal weight loss benefit (1–3%). Rarely prescribed for weight loss specifically.

Byetta (exenatide) — The original GLP-1 drug (2005). Requires twice-daily injections. Minimal weight loss (2–4%). Rarely used today except in cases where newer drugs are contraindicated.

Why the Differences?

Newer drugs are stronger because they:

  • Last longer in your system — Weekly injections instead of daily, which improves adherence
  • Act on more pathways — Tirzepatide (Zepbound, Mounjaro) targets both GLP-1 and GIP receptors, producing stronger appetite suppression
  • Reach higher doses safely — Better tolerability at higher concentrations means more weight loss before side effects become limiting

How to Choose

Your doctor will consider:

  • Budget — Ozempic/Mounjaro (diabetes) cost $200–400/month; Wegovy/Zepbound $1,500–1,800 without insurance
  • Goal — Diabetes management vs. weight loss only
  • Medical history — Some drugs are contraindicated in thyroid cancer, pancreatitis, or certain kidney conditions
  • Availability — Waitlists are shortest for first-gen and off-label diabetes options

Bottom Line

GLP-1 drugs work. The question is which one fits your timeline, budget, and goals. Newest ≠ always best—Saxenda is proven, available, and affordable; Wegovy and Zepbound are stronger but harder to access. Talk with your doctor about what's realistic for your situation.

References

  1. FDA: Semaglutide (Wegovy, Ozempic)
  2. FDA: Tirzepatide (Zepbound, Mounjaro) Approval
  3. NEJM: Semaglutide for Weight Loss (Wegovy Clinical Trial)
  4. PubMed: Tirzepatide Phase 3 Weight Loss Trial
  5. EndocrineWeb: GLP-1 Receptor Agonists Overview

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