Evidence guide
Which GLP-1 is best for weight loss? What the evidence says
There is no single best GLP-1 for everyone. There is published evidence on how they compare, and there are clear differences in approved uses, form and price. Here is that evidence, with citations.
Programs that list Zepbound, Wegovy and Foundayo
- Ro$39 first month, then $149/mo membership (from $74/mo prepaid yearly). Lists Wegovy pill & pen, Zepbound, Foundayo.
- WeightWatchers Med+$25 first month, then $74–$84/mo on a 12- or 6-month plan. Lists Wegovy pill & pen, Zepbound, Foundayo.
- Amazon One Medical$39 message or $59 video visit, no membership required. Wegovy pill & injection, Zepbound, Foundayo.
- Hims & Hers$39 first month, then $149/mo; medicine from $149/mo. Cash-pay Wegovy pill & pen, Zepbound, Foundayo.
Not a ranking; facts from official pages, checked 9 November 2026. Buttons open the program’s site; we may earn a commission from some links. Disclosure.
Educational, not medical advice. Only a clinician licensed in your state can decide whether a prescription medicine is right for you. We do not give dosing instructions. In an emergency, call 911. Medical disclaimer.
Disclosure: buttons go to official websites. If we add partner links later, a signup may earn us a commission at no cost to you. Advertising disclosure. We do not promote compounded or “research use only” GLP-1 products.
Short answer: in the SURMOUNT-5 head-to-head trial, tirzepatide (Zepbound) produced more average weight reduction than semaglutide (Wegovy). But Wegovy has a cardiovascular indication and a pill version, and Foundayo is a pill without food or water timing rules. The best choice is the one a clinician judges suitable for you, at a price you can sustain.
The FDA-approved options side by side
| Medicine | Form | Approved uses besides weight | Key published trial result | Self-pay from |
|---|---|---|---|---|
| Zepbound (tirzepatide) | weekly injection | Obstructive sleep apnea in adults with obesity | SURMOUNT-5 head-to-head vs semaglutide (Wegovy's ingredient): −20.2% vs −13.7% mean weight change at 72 weeks Aronne LJ et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity (SURMOUNT-5). N Engl J Med 2025 ↗ | $299 |
| Wegovy injection (semaglutide) | weekly injection | Cardiovascular risk reduction; MASH in certain adults | Comparator in SURMOUNT-5 (above) | $199 intro, then $349 |
| Wegovy pill (semaglutide) | daily tablet | Cardiovascular risk reduction | OASIS 4 (64 weeks, 307 adults): 13.6% vs 2.4% with placebo; 16.6% vs 2.7% among those who stayed on treatment Novo Nordisk: Wegovy pill FDA approval and OASIS 4 results ↗ | $149 |
| Foundayo (orforglipron) | daily tablet | None listed in the approval announcement | Approved on two 72-week placebo-controlled trials FDA: Foundayo approval, 1 Apr 2026 ↗ | $149 |
| Saxenda (liraglutide) | daily injection | None listed | Older daily option; no head-to-head result cited here | Not checked |
What the head-to-head evidence shows
SURMOUNT-5 was a 72-week, open-label phase 3b trial in 751 adults with obesity, or overweight with a weight-related condition, and without type 2 diabetes. Mean weight change was −20.2% with tirzepatide and −13.7% with semaglutide; waist circumference fell by 18.4 cm and 13.0 cm. Gastrointestinal adverse events were the most common in both groups. Eli Lilly, which makes tirzepatide, funded the trial. Aronne LJ et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity (SURMOUNT-5). N Engl J Med 2025 ↗
No published head-to-head trial compares the two pills with each other or with the injections, so treat any precise ranking of them with caution.
Factors a clinician will weigh
- Your other conditions. Wegovy (injection and pill) is approved to reduce cardiovascular risk in adults with established cardiovascular disease and obesity or overweight. Zepbound is approved for moderate-to-severe obstructive sleep apnea in adults with obesity.
- Pill or injection. Weekly injections versus daily tablets; see GLP-1 pills.
- Side effects and history. Every label carries warnings, including a boxed thyroid C-cell tumor warning, and lists who should not use the medicine.
- Coverage and cost. A medicine you cannot afford to continue is not the best option. See GLP-1 cost.
Where to get assessed
Compare online programs by which medicines they list and how they handle insurance. A prescription is never guaranteed.
Related guides
- GLP-1 cost in 2026: Zepbound, Wegovy, Wegovy pill and Foundayo prices
- Cheapest FDA-approved GLP-1 without insurance
- Zepbound vs Wegovy: cost, trial results and differences
- GLP-1 pills: Wegovy pill vs Foundayo
- FDA-approved GLP-1 medicines in the US
Sources
- Aronne LJ et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity (SURMOUNT-5). N Engl J Med 2025 ↗ — checked 9 November 2026.
- Novo Nordisk: Wegovy pill FDA approval and OASIS 4 results ↗ — checked 9 November 2026.
- FDA: Foundayo approval, 1 Apr 2026 ↗ — checked 9 November 2026.
- Lilly: FDA approves Foundayo, 1 Apr 2026 ↗ — checked 9 November 2026.
- FDA Zepbound approval announcement ↗ — checked 9 November 2026.
- Zepbound prescribing information (Lilly, PDF) ↗ — checked 9 November 2026.
- FDA approval package with Wegovy labeling, May 2026 (PDF) ↗ — checked 9 November 2026.
- Wegovy cost & coverage (Novo Nordisk) ↗ — checked 9 November 2026.
- LillyDirect: Zepbound self-pay ↗ — checked 9 November 2026.
- Foundayo coverage & savings (Lilly) ↗ — checked 9 November 2026.
- Drugs@FDA: current product labeling ↗ — checked 9 November 2026.
Frequently asked questions
Which GLP-1 is most effective for weight loss?
In SURMOUNT-5 (NEJM, 2025), a head-to-head trial of the two leading injections, tirzepatide (Zepbound) produced greater average weight reduction than semaglutide (Wegovy) at 72 weeks: 20.2% versus 13.7%. The trial was open-label and funded by Eli Lilly. Averages do not predict an individual result, and effectiveness is only one factor a clinician weighs.
Is Zepbound better than Wegovy?
Zepbound showed greater average weight reduction in SURMOUNT-5, but Wegovy has an FDA-approved cardiovascular risk-reduction use and a pill form. Which suits a person depends on health history, coverage and preferences. See our Zepbound vs Wegovy guide.
Which GLP-1 has the fewest side effects?
We cannot say one has the fewest. Gastrointestinal effects were the most common adverse events for both medicines in SURMOUNT-5, and every label lists serious warnings. Compare the FDA labels with your clinician.
Is a pill as good as an injection?
There is no head-to-head trial between the GLP-1 pills and injections on this page. Each pill was approved on its own placebo-controlled trials. Pills avoid injections but come with their own instructions in the label.
Can I choose which GLP-1 I get?
You can tell the clinician your preference, but the clinician decides what is appropriate, and insurance coverage often limits which brand is affordable.