GLP-1 Medications: Every Option Compared

The GLP-1 Medication Landscape

GLP-1 receptor agonists have been in use for diabetes treatment since 2005. Their use for weight loss is more recent — Wegovy (semaglutide 2.4 mg) received FDA approval for obesity in 2021, and Zepbound (tirzepatide) in 2023.

Here's every major option:

Semaglutide (Ozempic / Wegovy / Rybelsus)

Semaglutide is the active ingredient in three products:

• Ozempic — 0.5 mg, 1 mg, or 2 mg weekly injection. FDA-approved for type 2 diabetes. Widely prescribed off-label for weight loss.
• Wegovy — 2.4 mg weekly injection. FDA-approved specifically for chronic weight management in adults with obesity or overweight plus a weight-related condition.
• Rybelsus — 7 mg or 14 mg daily oral tablet. FDA-approved for type 2 diabetes. Substantially less effective for weight loss than injectable semaglutide.

Average weight loss on Wegovy 2.4 mg: 14.9% at 68 weeks (STEP 1 trial).

Tirzepatide (Mounjaro / Zepbound)

Tirzepatide is a dual GIP/GLP-1 receptor agonist — it activates two incretin receptors, not just one. The GIP receptor co-activation appears to amplify weight loss beyond what GLP-1 alone achieves.

• Mounjaro — 5, 10, or 15 mg weekly injection. FDA-approved for type 2 diabetes.
• Zepbound — Same doses. FDA-approved for obesity and overweight with weight-related conditions.

Average weight loss on Zepbound 15 mg: 20.9% at 72 weeks (SURMOUNT-1 trial) — the highest ever recorded for an approved weight loss medication.

Liraglutide (Victoza / Saxenda)

An older GLP-1 medication requiring daily (not weekly) injection. Less effective than semaglutide for weight loss. Average weight loss ~5–8%.

• Victoza — Diabetes indication
• Saxenda — Obesity indication

Still prescribed, particularly for patients who don't tolerate semaglutide or tirzepatide, but largely being replaced by once-weekly options.

Compounded Semaglutide and Tirzepatide

During the drug shortage period of 2022–2024, compounding pharmacies were permitted to produce copies of semaglutide and tirzepatide at significantly lower cost. As of 2025, the FDA has placed stricter limits on compounding. These products vary in quality, concentration accuracy, and sterility standards — proceed cautiously and only use FDA-registered facilities.

Choosing Between Them

Tirzepatide produces more weight loss on average and has become the preferred choice for many providers. However, individual response varies — some patients do better on semaglutide. Insurance coverage often determines which is accessible.

Bottom Line

For weight loss, tirzepatide (Zepbound) is the most effective option currently approved. For patients who can't access or tolerate tirzepatide, semaglutide (Wegovy) is highly effective and the more established choice. Both require a prescription and are available via telehealth.

Sources

• Wilding JPH et al., "Once-Weekly Semaglutide in Adults with Overweight or Obesity," NEJM, 2021
• Jastreboff AM et al., "Tirzepatide Once Weekly for the Treatment of Obesity," NEJM, 2022
• US FDA, "FDA Approves New Medication for Chronic Weight Management," FDA.gov, 2021