Scientific deep-dive
What Is the Best GLP-1 for Weight Loss? Ranked by FDA Evidence (2026)
There is no single "best" GLP-1 — there are four FDA-approved AOMs ranked by different criteria. Ranked by raw % total body-weight loss: Zepbound (tirzepatide 15 mg) -20.9% at 72 wk in SURMOUNT-1 (Jastreboff NEJM 2022) > Wegovy (semaglutide 2.4 mg) -14.9% at 68 wk in STEP-1 (Wilding NEJM 2021) > Foundayo (orforglipron 17.2 mg oral) -11.1% at 72 wk in ATTAIN-1 (Wharton NEJM 2025) > Saxenda (liraglutide 3 mg) -8.0% at 56 wk in SCALE (Pi-Sunyer NEJM 2015). The head-to-head SURMOUNT-5 trial (Aronne NEJM 2025) confirmed tirzepatide produces greater weight loss than semaglutide directly. By cardiovascular evidence: Wegovy wins — the SELECT trial (Lincoff NEJM 2023) is the only GLP-1 obesity trial with a positive MACE outcome (HR 0.80). By oral route: Foundayo is the only FDA-approved oral GLP-1 for chronic weight management. By cost (cash-pay 2026): Foundayo $149/mo ties as cheapest. By needle aversion: Foundayo. By weight-loss magnitude: Zepbound. By CV protection: Wegovy. Pipeline retatrutide hit -24.2% in phase 2 (Jastreboff NEJM 2023) but is investigational. The honest answer depends on which criterion matters for YOUR goal.
There is no single “best” GLP-1 for weight loss — there are four FDA-approved GLP-1 anti-obesity medications in 2026 (Saxenda, Wegovy, Zepbound, Foundayo) plus one investigational pipeline contender (retatrutide), and each ranks differently depending on whether you weight magnitude, cardiovascular protection, oral route, cost, or injection frequency. The honest answer is: Zepbound wins on raw weight-loss magnitude (−20.9% in SURMOUNT-1[2]), Wegovy wins on cardiovascular outcomes evidence (the only positive MACE trial in the class[6]), Foundayo wins on oral route and lowest needle-aversion friction, and Saxenda generic (Teva liraglutide, August 2025) wins on price among injectables. Here is the evidence-graded ranking with verbatim phase 3 endpoints.
About this article
Every drug ranked below is FDA-approved with a published label on DailyMed (NIH-hosted). Phase 3 efficacy is sourced from the canonical pivotal trial publications cited in PubMed and the verbatim FDA prescribing information. Pricing was verified live on 2026-05-17 from manufacturer self-pay portals (NovoCare, LillyDirect) and Amazon Pharmacy. DailyMed SetIDs: Wegovy ee06186f-2aa3-4990-a760-757579d8f77b; Zepbound 487cd7e7-434c-4925-99fa-aa80b1cc776b; Foundayo 8ac446c5-feba-474f-a103-23facb9b5c62; Saxenda 3946d389-0926-4f77-a708-0acb8153b143. For the broader landscape, see our GLP-1 complete guide and the full GLP-1 medication reference.
TL;DR — the criterion-dependent answer
- Best by raw %TBWL (magnitude): Zepbound (tirzepatide 15 mg weekly). −20.9% at 72 weeks in SURMOUNT-1[2]. Confirmed superior to semaglutide in the head-to-head SURMOUNT-5 trial[3].
- Best by cardiovascular outcomes evidence: Wegovy (semaglutide 2.4 mg weekly). The SELECT trial[6] is the only chronic-weight-management GLP-1 trial with a positive MACE outcome (HR 0.80, 20% relative reduction in CV death / MI / stroke) in adults with established CVD and overweight or obesity without diabetes.
- Best for oral route / needle aversion: Foundayo (orforglipron 17.2 mg oral daily). FDA-approved April 1, 2026. The first FDA-approved oral medication for chronic weight management in the GLP-1 era. −11.1% at 72 weeks in ATTAIN-1[4].
- Best by cash-pay cost (2026): Foundayo at $149/month at LillyDirect or Amazon Pharmacy ties as cheapest brand-name path; the new Teva generic liraglutide 3 mg (FDA-approved August 28, 2025) is the first generic GLP-1 receptor agonist for weight management and a price-disruption event for the Saxenda channel.
- Pipeline / future winner: Retatrutide (Eli Lilly LY3437943, GIP / GLP-1 / glucagon triple agonist) hit −24.2% body weight at 48 weeks in the TRIUMPH-1 phase 2 trial[7]. Investigational — not FDA-approved. Phase 3 TRIUMPH program reads out throughout 2026.
Cross-trial efficacy comparisons across STEP-1, SURMOUNT-1, ATTAIN-1, and SCALE are indirect — the trials enrolled different populations and ran different durations. The only direct head-to-head trial in the chronic weight-management class is SURMOUNT-5 (tirzepatide vs semaglutide); we cover it in detail below. For the deeper molecule-level tirzepatide vs semaglutide pharmacology, see our tirzepatide vs semaglutide head-to-head guide.
Ranking by weight-loss magnitude (cross-trial indirect comparison)
Magnitude comparison
Mean percent total body-weight loss at the pivotal trial endpoint for every FDA-approved GLP-1 anti-obesity medication, plus the retatrutide pipeline phase 2 readout. Cross-trial comparison: trials enrolled different populations and ran different durations. Direct head-to-head data is limited to SURMOUNT-5 (tirzepatide vs semaglutide).[1][2][3][4][5][7]
- Saxenda — liraglutide 3 mg daily (SCALE, 56 wk)8 % TBWLsmallest effect; once-daily injection
- Foundayo — orforglipron 17.2 mg oral daily (ATTAIN-1, 72 wk)11.1 % TBWLonly FDA-approved oral GLP-1 for weight
- Wegovy — semaglutide 2.4 mg weekly (STEP-1, 68 wk)14.9 % TBWLbest cardiovascular outcomes evidence
- Zepbound — tirzepatide 15 mg weekly (SURMOUNT-1, 72 wk)20.9 % TBWLhighest FDA-approved magnitude
- Retatrutide — 12 mg phase 2 (TRIUMPH-1, 48 wk) — investigational24.2 % TBWLNOT FDA-approved
The ranking by magnitude is unambiguous in direction: Zepbound > Wegovy > Foundayo > Saxenda among FDA-approved options, with retatrutide above all of them on phase 2 data but not yet a real-world prescription. The bars are indirect because the trials differed; the direct head-to-head data point that nails the Zepbound > Wegovy direction is SURMOUNT-5, covered next.
The head-to-head trial: SURMOUNT-5 (tirzepatide vs semaglutide)
SURMOUNT-5[3] is the first FDA-quality randomized direct comparison of tirzepatide (the molecule in Zepbound and Mounjaro) vs semaglutide (the molecule in Wegovy and Ozempic) in adults with obesity without type 2 diabetes — the exact population covered by the chronic weight-management indications on both labels. The trial randomized adults with BMI ≥30 (or ≥27 with one weight-related comorbidity other than diabetes) to tirzepatide maintenance (up to 15 mg weekly) vs semaglutide maintenance (up to 2.4 mg weekly) over 72 weeks.
The result: tirzepatide produced greater mean weight loss than semaglutide across the primary and key secondary endpoints. This is the empirical anchor for the “Zepbound > Wegovy on magnitude” statement — it is no longer cross-trial inference, it is a randomized direct comparison published in NEJM 2025. For verbatim trial design + endpoint table + how it changes the prescribing conversation, see our tirzepatide vs semaglutide head-to-head guide.
Ranking by cardiovascular outcomes evidence
The cardiovascular outcomes ranking inverts the magnitude ranking. Wegovy wins decisively:
- SELECT trial[6] (Lincoff NEJM 2023, n=17,604) randomized adults with established CVD (prior MI, stroke, or symptomatic PAD) and overweight or obesity (BMI ≥27) without diabetes to semaglutide 2.4 mg weekly vs placebo. The primary endpoint was 3-point MACE (cardiovascular death, non-fatal MI, non-fatal stroke). Result: HR 0.80 (95% CI 0.72–0.90), p<0.001 — a 20% relative reduction in MACE. Mean follow-up ~40 months.
- Zepbound: No published cardiovascular outcomes trial in the chronic weight-management population to date. SURPASS-CVOT is the corresponding tirzepatide CVOT but enrolls patients with type 2 diabetes (not the weight-management indication) and reads out in 2027.
- Foundayo: No CVOT. ATTAIN-1[4] measured weight as primary; cardiovascular outcomes are not yet established at trial-quality level.
- Saxenda: The LEADER trial measured cardiovascular outcomes with liraglutide 1.8 mg in type 2 diabetes (not the 3.0 mg weight-management dose). It is not a Saxenda CVOT.
For patients with established CVD or high cardiovascular risk, Wegovy is the only FDA-approved weight-management GLP-1 with a positive randomized CV outcome. Some payers (Medicare Part D notably) added Wegovy CV-risk-reduction coverage in 2024 specifically based on SELECT, which expands access independent of the BMI-only weight indication. For the policy implication, see our GLP-1 Medicare/Medicaid/commercial coverage guide.
Ranking by route: oral vs injectable
If needle aversion is the dominant constraint, the ranking collapses: Foundayo is the only FDA-approved oral GLP-1 receptor agonist for chronic weight management. Orforglipron is a non-peptide small-molecule, which means it does not require the strict fasting protocol Rybelsus (oral semaglutide, T2D-indicated) demands. Per the Foundayo §2 dosing label, the tablet can be taken with or without food.
Cross-trial: Foundayo's −11.1% in ATTAIN-1[4] sits between Saxenda's −8.0% in SCALE[5] and Wegovy's −14.9% in STEP-1[1]. That is meaningfully less weight loss than Wegovy or Zepbound, but it is the only oral path in the FDA-approved GLP-1 class for weight management. For the deeper Foundayo vs Wegovy vs Zepbound comparison see our Foundayo vs Wegovy vs Zepbound comparison and the broader oral GLP-1 pills comparison.
Ranking by cash-pay cost (2026 manufacturer self-pay paths)
For uninsured patients or insured patients facing high deductibles or non-coverage, the cash-pay rank order (verified 2026-05-17) is:
| Drug | Manufacturer cash-pay path | Monthly |
|---|---|---|
| Foundayo | LillyDirect Self Pay / Amazon Pharmacy | $149/mo |
| Wegovy (oral pill 1.5 / 4 mg) | NovoCare Pharmacy (through Aug 31, 2026) | $149/mo |
| Wegovy (standard pen 0.25–2.4 mg) | NovoCare Pharmacy self-pay | $299/mo |
| Zepbound (vials, 2.5–15 mg) | LillyDirect Self Pay | $349–$499/mo |
| Wegovy HD (7.2 mg pen) | NovoCare Pharmacy self-pay | $399/mo |
| Generic liraglutide 3 mg | Teva (FDA-approved Aug 28, 2025) — first generic GLP-1 RA for weight management | rolling out; price disruption expected |
For the channel-by-channel deeper cost breakdown including Costco CMPP via Sesame, Sam's Club Plus Pharmacy, and GoodRx coupon mechanics, see our Zepbound vs Wegovy cost comparison and the live GLP-1 pricing index.
Ranking by side-effect profile
Across all four FDA-approved GLP-1 weight-management drugs, the §6 Adverse Reactions tables are dominated by GI events — nausea, diarrhea, vomiting, constipation. The magnitudes vary modestly but are not the meaningful differentiator across the class:
- Wegovy §6.1: nausea ~44%, diarrhea ~30%, vomiting ~24%, constipation ~24% (STEP-1 treatment period).
- Zepbound §6.1: nausea ~29%, diarrhea ~23%, constipation ~17%, vomiting ~10% (SURMOUNT-1, 15 mg dose).
- Foundayo §6.1: GI events are most common; oral pharmacokinetics produce a different absorption curve than injectable depots, which in some patients translates to milder peak GI symptoms.
- Saxenda §6.1: nausea ~39%, diarrhea ~21%, constipation ~19%, vomiting ~16% (SCALE).
All four labels carry the class boxed warning for thyroid C-cell tumors based on rodent carcinogenicity studies (medullary thyroid carcinoma seen in rodents; human relevance not determined). All four are contraindicated in patients with a personal or family history of medullary thyroid carcinoma or in patients with Multiple Endocrine Neoplasia syndrome type 2 (MEN 2). All four carry warnings for acute pancreatitis, gallbladder disease, acute kidney injury (from volume depletion secondary to GI loss), hypoglycemia (especially when combined with sulfonylureas or insulin), and diabetic retinopathy complications. For the side-effect compare directly between Zepbound and Wegovy see our Zepbound vs Wegovy side effects.
“Best” depends on YOUR goal — a decision framework
Pick the row that matches your dominant constraint and the right answer falls out:
| Your goal | Best FDA-approved GLP-1 |
|---|---|
| Maximum mean weight loss | Zepbound |
| Cardiovascular risk reduction | Wegovy |
| Oral instead of injection | Foundayo |
| Lowest cash-pay cost | Foundayo or generic liraglutide |
| Heart-failure with preserved EF (HFpEF) + obesity | Wegovy |
| Adolescent (age 12–17) | Wegovy or Saxenda |
| Obstructive sleep apnea (OSA) | Zepbound |
| Chronic kidney disease + obesity | Wegovy (off-label CKD) / Ozempic (T2D CKD) |
Common bad takes (and why they are wrong)
- “Highest %TBWL is always best.” Wrong. Weight loss magnitude is one criterion. For a patient with established CVD, the +6% incremental weight loss from Zepbound vs Wegovy does not outweigh the only MACE-positive trial in the class (SELECT[6]). For a patient with severe needle aversion, even the highest-magnitude injectable is worse than the oral alternative they will actually take.
- “Ozempic and Wegovy are different drugs.” Wrong. Same molecule (semaglutide), different brand names tied to different FDA indications. Ozempic is labeled for type 2 diabetes; Wegovy is labeled for chronic weight management. The maximum dose differs (Ozempic 2 mg vs Wegovy 2.4 mg). For the deeper disambiguation see our Wegovy / Ozempic / Zepbound / Mounjaro brand-name cheat sheet.
- “Mounjaro is better than Zepbound for weight loss.” Wrong. Same molecule (tirzepatide), different FDA indications. Mounjaro is the type-2-diabetes-indicated brand; Zepbound is the chronic-weight-management-indicated brand. For the disambiguation see our Mounjaro vs Zepbound tirzepatide disambiguation.
- “Compounded semaglutide is just as good as Wegovy.” Not equivalent. Compounded semaglutide is not FDA-approved. The FDA enforcement-discretion grace period that allowed broad compounding during the semaglutide drug-shortage classification ended February 2025. There is no FDA-trial efficacy or safety data for compounded versions specifically. For the regulatory framing see our compounded tirzepatide vs compounded semaglutide guide.
- “Retatrutide is the new best GLP-1.” Premature. Retatrutide is investigational and not FDA-approved. The −24.2% phase 2 headline number[7] is genuinely the highest published weight loss in the GLP-1-class pipeline, but phase 2 data routinely does not replicate at phase 3 scale, and safety + long-term tolerability profiles mature only at FDA submission. The phase 3 TRIUMPH program reads out throughout 2026. Until then, Zepbound is the highest-magnitude FDA-approved option. For the detailed pipeline walk-through see our retatrutide triple agonist evidence.
Bottom line
- By raw weight-loss magnitude: Zepbound (tirzepatide 15 mg). −20.9% in SURMOUNT-1; confirmed superior to semaglutide in the SURMOUNT-5 head-to-head.
- By cardiovascular outcomes evidence: Wegovy (semaglutide 2.4 mg). Only positive MACE trial in the chronic-weight-management class (SELECT, HR 0.80).
- By oral route / needle aversion: Foundayo (orforglipron 17.2 mg oral). The first and only FDA-approved oral GLP-1 receptor agonist for chronic weight management.
- By cost (cash-pay 2026): Foundayo $149/mo or generic liraglutide 3 mg (Teva, FDA-approved August 28, 2025 — the first generic GLP-1 RA for weight management).
- Pipeline future winner: Retatrutide phase 2 −24.2%, but investigational, not FDA-approved, and TRIUMPH phase 3 data is the gating event throughout 2026.
There is no single “best GLP-1 for weight loss” in the abstract. The question always carries an unstated criterion: best for what. Once the criterion is named, the FDA-evidence-graded answer is unambiguous.
Related research
- Tirzepatide vs semaglutide head-to-head — verbatim SURMOUNT-5 trial design + primary endpoint table + the prescribing-conversation implications.
- Wegovy alternatives (2026): Zepbound, Foundayo, Saxenda & cheaper compounded semaglutide options — the Wegovy-anchored alternatives walkthrough with verbatim FDA labels and verified 2026 prices.
- Foundayo vs Wegovy vs Zepbound comparison — the three-way decision walk-through with verbatim ATTAIN-1, STEP-1, and SURMOUNT-1 endpoints.
- Zepbound vs Wegovy cost comparison — verbatim NovoCare and LillyDirect 2026 prices across every dose.
- Zepbound vs Wegovy side effects — §6 Adverse Reactions tables compared head-to-head.
- Saxenda (liraglutide) FDA label, SCALE evidence & Teva generic update — the August 2025 first-generic-GLP-1 watershed.
- Retatrutide triple agonist evidence — the phase 2 −24.2% pipeline contender and why phase 3 readout matters.
- Wegovy / Ozempic / Zepbound / Mounjaro brand-name cheat sheet — the same-molecule-different-brand disambiguation.
- Full GLP-1 medication reference — every FDA-approved and pipeline GLP-1 molecule.
- Versión en español: ¿Cuál es el mejor GLP-1 para perder peso? Ranking por evidencia FDA
References
- 1.Wilding JPH, Batterham RL, Calanna S, et al. (STEP 1 Study Group) Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). N Engl J Med. 2021. PMID: 33567185.
- 2.Jastreboff AM, Aronne LJ, Ahmad NN, et al. (SURMOUNT-1 Investigators) Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). N Engl J Med. 2022. PMID: 35658024.
- 3.Aronne LJ, Horn DB, le Roux CW, et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity (SURMOUNT-5). N Engl J Med. 2025. PMID: 40353578.
- 4.Wharton S, Aronne LJ, Behnke C, et al. (ATTAIN-1 Investigators) Orforglipron, an Oral Small-Molecule GLP-1 Receptor Agonist, in Adults with Obesity (ATTAIN-1). N Engl J Med. 2025. PMID: 40960239.
- 5.Pi-Sunyer X, Astrup A, Fujioka K, et al. (SCALE Obesity and Prediabetes NN8022-1839 Study Group) A Randomized, Controlled Trial of 3.0 mg of Liraglutide in Weight Management (SCALE Obesity and Prediabetes). N Engl J Med. 2015. PMID: 26132939.
- 6.Lincoff AM, Brown-Frandsen K, Colhoun HM, et al. (SELECT Trial Investigators) Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes (SELECT). N Engl J Med. 2023. PMID: 37952131.
- 7.Jastreboff AM, Kaplan LM, Frías JP, et al. (Retatrutide Phase 2 Obesity Trial Investigators) Triple-Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial. N Engl J Med. 2023. PMID: 37345787.
Glossary references
Key terms in this article, linked to their canonical definitions.
- Wegovy · Drugs and brands
- Zepbound · Drugs and brands
- Foundayo · Drugs and brands
- Saxenda · Drugs and brands
- Semaglutide · Drugs and brands
- Tirzepatide · Drugs and brands
- Orforglipron · Drugs and brands
- STEP-1 · Major trials
- SURMOUNT-1 · Major trials
- SELECT · Major trials