Best GLP-1 for Weight Loss, Ranked by Trial Results
"Best" and "strongest" are easy to claim and hard to prove — so here we rank the GLP-1 medications by the one objective measure that exists: average weight loss in their pivotal clinical trials. Then we cover the part the ranking can't: which one actually fits which situation.
The short answer
By average trial weight loss, Zepbound (tirzepatide) is the strongest GLP-1 for weight loss — about 22.5% mean body-weight reduction at 72 weeks (SURMOUNT-1) — ahead of Wegovy (semaglutide 2.4 mg, ~14.9%) and Saxenda (liraglutide, ~8%). But the strongest on average is not automatically the right one for you: indication, tolerability, insurance, and cost all matter.
Key takeaways
- #1 Zepbound (tirzepatide): ~22.5% mean weight loss at 72 wk (SURMOUNT-1).
- #2 Wegovy (semaglutide 2.4 mg): ~14.9% mean weight loss at 68 wk (STEP-1).
- #3 Saxenda (liraglutide 3.0 mg): ~8% mean weight loss at 56 wk (SCALE).
- #4 Ozempic (semaglutide): ~6% mean weight loss at 40 wk (SUSTAIN) — approved for diabetes, off-label for weight.
- Ranking is by average trial efficacy — "strongest" is not the same as "best for you" (indication, tolerability, coverage, cost).
| # | Medication | Mean weight loss | Trial | Dosing |
|---|---|---|---|---|
| 1 | Zepboundtirzepatide | ~22.5% | SURMOUNT-1 · 72 wk | Once-weekly injection |
| 2 | Wegovysemaglutide 2.4 mg | ~14.9% | STEP-1 · 68 wk | Once-weekly injection (oral pill also available) |
| 3 | Saxendaliraglutide 3.0 mg | ~8% | SCALE · 56 wk | Once-daily injection |
| 4 | Ozempicsemaglutide · diabetes drug (off-label for weight) | ~6% | SUSTAIN · 40 wk | Once-weekly injection |
Which is "best" depends on what you mean
Ranked purely by average weight loss, tirzepatide (Zepbound) leads. But "best for weight loss" means different things:
- Most weight loss on average: Zepbound (tirzepatide) — ~22.5% in SURMOUNT-1, the highest in the class.
- On-label semaglutide for weight: Wegovy — ~14.9% in STEP-1, and it also comes as an oral pill for people who want to avoid injections.
- If you have type 2 diabetes: Mounjaro (tirzepatide) or Ozempic (semaglutide) are the diabetes-labeled options; weight loss is often a welcome secondary effect.
- If cost or coverage is the constraint: the "best" may be whichever your insurance covers, or the cheapest cash route — see the cost pages linked below.
Why the strongest drug isn't automatically your best choice
Trial averages are measured in people who also followed a reduced-calorie diet and increased activity, and individual results vary widely around the mean. The right medication for you depends on your medical history and indication, how well you tolerate the gastrointestinal side effects, whether it is covered, and what it costs. Someone who can't tolerate the higher-efficacy drug will do better on one they can actually stay on. This page ranks efficacy; it is not medical advice, and the decision belongs to you and a licensed clinician.
Head-to-head: the one trial that compared them directly
Almost every “best GLP-1” ranking you will read is built from cross-trial comparison — separate studies, different populations, different protocols, results lined up side by side as though that were valid. It usually is not. One comparison is better than that, because the drugs were tested against each other in the same study.
SURMOUNT-5 (New England Journal of Medicine, 2025) randomized 751 adults with obesity but not diabetes to tirzepatide or semaglutide, each titrated to maximum tolerated dose, over 72 weeks. Average weight change was −20.2% with tirzepatide versus −13.7% with semaglutide.
Two honest caveats. Doses were titrated to what each person tolerated, so this reflects real-world use rather than top-dose-versus-top-dose. And “more on average” is a group result — plenty of people do excellently on the drug that came second, which is why the sections below matter more than the ranking.
The trade-off the ranking hides
In that same head-to-head, the drug that produced more weight loss also produced somewhat more gastrointestinal effects. Discontinuation rates for adverse events were low and broadly comparable, but more effect and more nausea travel together.
That matters practically because the most common reason people stop is tolerability during dose escalation, not disappointment with results. A drug you can stay on beats a stronger one you abandon in month two. If nausea has been a problem for you before, the useful conversation is about titration pace rather than which molecule is strongest — slower escalation changes the experience more than the choice of drug does.
The second indication that can decide it for you
This is the factor most rankings omit entirely, and for someone whose plan excludes weight-loss medication it can matter more than efficacy.
- Wegovy carries an FDA indication for cardiovascular risk reduction in adults with established heart disease plus overweight or obesity.
- Zepbound carries one for moderate-to-severe obstructive sleep apnea in adults with obesity.
Neither is a weight-loss use. Where a plan excludes weight-loss drugs as a category — common in employer plans, and required in Medicare Part D — coverage can still apply through these. Whether one fits you depends on your documented diagnosis, which is a question for your prescriber rather than an angle to adopt. See GLP-1 insurance coverage.
Cost per pound: the comparison that actually decides it
Monthly price alone misleads, because the drugs differ in how much weight they produce. Dividing annual cash cost by expected loss puts them on one scale. The example below uses a 250 lb starting weight and the SURMOUNT-5 mean percentages — your result will differ, which is exactly why the assumptions are stated rather than hidden.
| Cash scenario (250 lb start) | Per month | Per year | Approx. per pound |
|---|---|---|---|
| Zepbound, refilled within the window | $449 | $5,388 | ~$107 (20.2% ≈ 51 lb) |
| Zepbound, refill window missed | $699 | $8,388 | ~$166 (20.2% ≈ 51 lb) |
| Wegovy, cash maintenance | $349 | $4,188 | ~$122 (13.7% ≈ 34 lb) |
Note the middle row. Lilly's cheaper Zepbound maintenance price is conditional on buying each refill within 45 days of the previous fill — miss it and the same dose costs $250 more per month. Wegovy's cash maintenance pricing has no equivalent condition, which can make it cheaper in practice for someone whose refills are irregular.
And none of this applies if you have coverage — a copay beats every cash scenario here, which is why pricing the covered route first is worth more than any discount. Full cost breakdown · cost-per-pound calculator
What actually decides it, in order
| If this is you | Worth raising with your clinician |
|---|---|
| Your plan covers one and not the other | Formulary position settles this more often than efficacy does — and an exception is possible if the covered one fails you |
| You have established cardiovascular disease | Wegovy carries that indication; it is both a clinical point and a coverage route |
| You have moderate-to-severe sleep apnea | Zepbound carries that indication, which can bypass a weight-loss exclusion |
| Nausea has been a problem before | Titration pace matters more than which molecule you pick |
| You have type 2 diabetes | The diabetes-labeled options are usually far easier to get covered |
| Strong needle aversion | The oral semaglutide route exists — but read the daily-routine requirements first |
| Paying cash with irregular refills | The conditional price can cost more than the flat one; compare honestly |
What happens if you stop
Worth knowing before you pick, because it reframes the whole comparison. These drugs treat the drivers of weight while you take them — weight regain after discontinuation is well documented. The honest framing is ongoing treatment rather than a course you finish.
That changes which drug is genuinely “best”: not the one with the highest trial average, but the one you can tolerate, afford and stay on for years. A cheaper drug you maintain outperforms a stronger one you stop. Maintaining weight loss after stopping.
Compare GLP-1 providers & prices
SponsoredAdvertising disclosure: we may earn a commission if you sign up through these links, at no extra cost to you — it never affects our rankings. How we make money
Common questions about this medication
What is the best GLP-1 for weight loss?
By average weight loss in the pivotal trials, tirzepatide (Zepbound) is the strongest — about 22.5% mean body-weight reduction at 72 weeks in SURMOUNT-1, versus ~14.9% for semaglutide 2.4 mg (Wegovy) in STEP-1 and ~8% for liraglutide (Saxenda). But "strongest on average" is not the same as "best for you" — the right choice also depends on your medical history, tolerability, insurance coverage, and cost.
Is Zepbound or Wegovy better for weight loss?
On average trial results, Zepbound (tirzepatide) produced more weight loss than Wegovy (semaglutide 2.4 mg) — roughly 22.5% vs 14.9% — and a head-to-head trial (SURMOUNT-5) also favored tirzepatide. Both are FDA-approved for chronic weight management. Which is better for a given person still depends on side-effect tolerance, coverage, and clinician judgment.
Is Ozempic or Wegovy stronger for weight loss?
Wegovy. Both are semaglutide, but Wegovy is dosed higher (up to 2.4 mg) and is FDA-approved specifically for weight management, while Ozempic is approved for type 2 diabetes and dosed lower (up to 2 mg). For weight loss, Wegovy is the on-label, higher-dose option; Ozempic use for weight loss is off-label.
Which GLP-1 has the fewest side effects?
The GLP-1 class shares the same main side effects — nausea, diarrhea, constipation, and vomiting — mostly early and dose-related. No one drug is clearly "gentlest" for everyone; tolerability is individual and depends heavily on how slowly the dose is titrated. Discuss side-effect history with your prescriber rather than picking on side effects alone.
Does the strongest GLP-1 mean it is the right one for me?
No. The ranking here is by average weight loss in clinical trials — an objective measure of efficacy. The right medication for you also depends on your indication (diabetes vs weight), other conditions, how well you tolerate the dose, what your insurance covers, and cost. This page is information, not medical advice; the decision belongs to you and a licensed clinician.
Ranking uses published mean weight loss from SURMOUNT-1 (tirzepatide), STEP-1 (semaglutide), and SCALE (liraglutide). Efficacy ranking only — not medical advice, not a recommendation for any individual. Reviewed 2026-07-15.