Quick answer: Among the four most-used GLP-1 medications, tirzepatide (Mounjaro, Zepbound) produces the greatest average weight loss, followed by semaglutide (Ozempic, Wegovy), then liraglutide (Saxenda, Victoza) and dulaglutide (Trulicity), which is used mainly for type 2 diabetes. Tirzepatide, semaglutide, and dulaglutide are weekly injections; liraglutide is daily. In the head-to-head SURMOUNT-5 trial published in 2025, tirzepatide led to about 20.2% body-weight loss versus about 13.7% for semaglutide. The right choice depends on your goals, diabetes status, side-effect tolerance, and cost. FormBlends is one option to compare for compounded semaglutide and tirzepatide; compare options with our provider comparison tool or see semaglutide.
What are the top 4 GLP-1 drugs?
The four most common GLP-1 medications are tirzepatide, semaglutide, dulaglutide, and liraglutide. They all act on the GLP-1 pathway, a gut hormone system that lowers appetite, slows stomach emptying, and improves blood sugar. Tirzepatide is different from the others because it acts on a second pathway too (GIP), which is the main reason it tends to produce more average weight loss.
All four are injectables. Three are taken once weekly. Liraglutide is the outlier, taken once daily. Each has a brand sold for diabetes and, in some cases, a separate brand or dose approved for weight management.
Which GLP-1 drug is best for weight loss?
For average weight loss, tirzepatide leads, then semaglutide, then liraglutide, with dulaglutide producing the most modest weight effect since it was developed mainly for blood sugar control. The clearest evidence comes from the head-to-head SURMOUNT-5 trial published in 2025, where tirzepatide produced about 20.2% body-weight loss versus about 13.7% for semaglutide over 72 weeks.
"Best" still depends on the person. Average trial results do not predict any single outcome, and the right drug factors in diabetes status, how you tolerate side effects, dosing preference, and cost.
GLP-1 drugs compared side by side
| Drug | Brands | Dosing | Pathways | Approx. average weight loss (trials) | Primary use |
|---|---|---|---|---|---|
| Tirzepatide | Mounjaro, Zepbound | Weekly | GLP-1 + GIP | ~15 to 21% (SURMOUNT-1, by dose) | Diabetes, weight |
| Semaglutide | Ozempic, Wegovy | Weekly | GLP-1 | ~15% (STEP 1) | Diabetes, weight |
| Liraglutide | Victoza, Saxenda | Daily | GLP-1 | ~8% (SCALE) | Diabetes, weight |
| Dulaglutide | Trulicity | Weekly | GLP-1 | More modest weight effect (AWARD) | Diabetes |
Figures are approximate, drawn from different trials and populations. The cleanest direct comparison is the SURMOUNT-5 head-to-head of tirzepatide and semaglutide noted above.
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Take the Assessment →Semaglutide vs tirzepatide: what is the difference?
The core difference is how many hormone pathways each one targets. Semaglutide mimics GLP-1 only. Tirzepatide mimics GLP-1 and GIP. Targeting both pathways is why researchers expected, and then measured, greater average weight loss with tirzepatide in the head-to-head data.
Both are weekly injections that lower appetite and slow digestion. Both can cause GI side effects like nausea and diarrhea. Tirzepatide is the stronger option on average for weight, while semaglutide has a longer real-world track record and may be enough for more modest goals. FormBlends offers compounded versions of both.
Dulaglutide vs semaglutide for weight loss
Semaglutide produces more weight loss than dulaglutide. Dulaglutide (Trulicity) was developed primarily to manage type 2 diabetes, and while it can lead to some weight reduction, the effect is smaller than semaglutide's. Head-to-head diabetes trials in the drug class studied in the AWARD and SUSTAIN programs generally showed semaglutide outperforming dulaglutide on both A1c and weight.
If weight loss is the main goal, semaglutide or tirzepatide is the stronger choice. Dulaglutide makes more sense when blood sugar control is the priority and weight loss is a secondary benefit.
How do GLP-1 side effects compare?
Side effects are broadly similar across the class because all four act on GLP-1. The most common are gastrointestinal: nausea, diarrhea, constipation, and vomiting. These are usually mild to moderate and tend to ease as the body adjusts, and they are most noticeable when starting or after a dose increase.
Starting low and increasing the dose slowly is the standard way to limit these effects. Tell your prescriber about severe nausea, an inability to keep fluids down, or severe stomach pain. The daily dosing of liraglutide means side effects are managed on a daily rhythm, while the weekly drugs concentrate the dose once a week.
How much do GLP-1 drugs cost, and how do you choose?
Branded GLP-1 medications carry high list prices, and real-world cost depends heavily on insurance, manufacturer programs, and whether a compounded option is used. Because pricing changes often and varies by person, the practical move is to compare your specific options rather than rely on a single number.
To choose, weigh your weight-loss goal, whether you have diabetes, how you tolerate side effects, dosing preference (weekly vs daily), and cost. Talk with a prescriber who can match a drug to your history. FormBlends is one option to compare for compounded semaglutide and tirzepatide, and the provider comparison tool lays out the choices clearly.
Frequently asked questions
Which GLP-1 drug causes the most weight loss?
Tirzepatide produces the greatest average weight loss, ahead of semaglutide, then liraglutide, with dulaglutide the most modest.
Is tirzepatide better than semaglutide?
On average it led to more weight loss in the head-to-head SURMOUNT-5 trial, but the best choice depends on your goals, tolerance, and cost.
Which GLP-1 drugs are weekly vs daily?
Tirzepatide, semaglutide, and dulaglutide are weekly. Liraglutide is daily.
Can dulaglutide be used for weight loss?
It can lead to some weight loss, but it was developed mainly for type 2 diabetes and produces less weight loss than semaglutide or tirzepatide.
Do all GLP-1 drugs have the same side effects?
The side-effect profiles are similar, mostly gastrointestinal, since all act on the GLP-1 pathway. Individual tolerance varies.
Which GLP-1 is best if I have type 2 diabetes?
All four are used in diabetes. The choice depends on your A1c goals, weight goals, and your prescriber's judgment.
Where can I start compounded semaglutide or tirzepatide?
FormBlends offers both with prescriber oversight. Start at semaglutide or use the provider comparison tool.
Sources
- Aronne LJ, et al. Tirzepatide vs Semaglutide for Weight Management (SURMOUNT-5). New England Journal of Medicine, 2025. https://www.nejm.org/doi/full/10.1056/NEJMoa2416394
- Jastreboff AM, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). New England Journal of Medicine. https://www.nejm.org/doi/full/10.1056/NEJMoa2206038
- Wilding JPH, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). New England Journal of Medicine. https://www.nejm.org/doi/full/10.1056/NEJMoa2032183
- Pi-Sunyer X, et al. A Randomized, Controlled Trial of Liraglutide for Weight Management (SCALE). New England Journal of Medicine. https://www.nejm.org/doi/full/10.1056/NEJMoa1411892
- U.S. FDA. Prescribing information for Zepbound, Wegovy, Saxenda, and Trulicity. https://www.accessdata.fda.gov/
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