Wegovy and Zepbound are the only two GLP-1 medications with dedicated FDA approval for chronic weight management. Not diabetes drugs being used off-label. Not compounded versions. These are the treatments specifically designed, trialled, and approved to help people lose weight.
So if your doctor says "we should consider a GLP-1 for weight management," the conversation almost always comes down to these two. And as of 2026, the comparison has become considerably more nuanced than it was a year ago.
The basics
Wegovy (semaglutide, Novo Nordisk) — GLP-1 receptor agonist. Approved June 2021 for weight management. Available as once-weekly injection (1.7mg, 2.4mg, or 7.2mg) and once-daily pill (25mg). Also approved for cardiovascular risk reduction. Core patent expired March 2026.
Zepbound (tirzepatide, Eli Lilly) — Dual GIP/GLP-1 receptor agonist. Approved November 2023 for weight management. Available as once-weekly injection only (5mg, 10mg, or 15mg). Also approved for obstructive sleep apnoea. Patent-protected through the early 2030s.
Weight loss results
Let's start with what the clinical trials say, then discuss what real-world use looks like.
Wegovy 2.4mg (standard dose): The STEP 1 trial showed 14.9% mean body weight loss at 68 weeks (Wilding et al., 2021). About one-third of participants lost 20% or more.
Wegovy HD 7.2mg (high dose, approved March 2026): The STEP UP trial showed 20.7% mean weight loss at 72 weeks, with approximately one in three participants achieving 25% or greater weight loss (Wharton et al., 2025).
Wegovy pill 25mg: The OASIS 4 trial showed 16.6% mean weight loss at 64 weeks with full adherence (Wharton et al., 2024).
Zepbound 15mg: The SURMOUNT-1 trial showed 22.5% mean weight loss at 72 weeks. Over one-third of participants lost 25% or more. (Jastreboff et al., 2022).
Head-to-head (SURMOUNT-5): When tested directly against each other at maximum standard doses — Zepbound 15mg vs Wegovy 2.4mg — tirzepatide produced 20.2% mean weight loss versus 13.7% for semaglutide (Aronne et al., 2025).
But here's where 2026 changes the story. Wegovy HD at 7.2mg produces 20.7% mean weight loss — essentially matching Zepbound 15mg. This means if you can tolerate the dose escalation to 7.2mg, the weight loss gap between these products effectively disappears.
A large real-world study comparing GLP-1 medications to bariatric surgery found that surgery patients lost roughly five times more weight than those on GLP-1s after two years — but real-world adherence and dropout rates significantly blunted the drugs' effectiveness compared to clinical trial settings. Staying on the medication is at least as important as which medication you choose.
Formulation options: Wegovy's advantage
This is where Wegovy has pulled ahead in 2026.
Wegovy now offers:
- Once-weekly injection at three dose levels (1.7mg, 2.4mg, 7.2mg)
- Once-daily pill (25mg)
Zepbound offers:
- Once-weekly injection at three dose levels (5mg, 10mg, 15mg)
If you can't stand needles, or if injection adherence is a challenge, Wegovy's pill option is a meaningful differentiator. The pill produced slightly less weight loss than the injection (16.6% vs 20.7% at their respective best doses) — but a pill you actually take consistently beats an injection you skip.
Eli Lilly's oral GLP-1 — orforglipron — is under FDA review and could close this gap. But as of April 2026, it's not yet approved.
Beyond weight loss: different strengths
Wegovy's unique advantage: cardiovascular risk reduction. The SELECT trial demonstrated a 20% reduction in major adverse cardiovascular events (death, heart attack, stroke) in adults with obesity and established cardiovascular disease (Lincoff et al., 2023). No other weight-loss medication has this indication. If you have heart disease, this matters enormously.
Zepbound's unique advantage: obstructive sleep apnoea. Tirzepatide received FDA approval for moderate-to-severe obstructive sleep apnoea in adults with obesity, based on the SURMOUNT-OSA trial showing significant reductions in apnoea-hypopnoea index. If sleep apnoea is part of your health picture, this is relevant.
Semaglutide also has FDA approval for MASH (fatty liver disease) and chronic kidney disease under the Wegovy/Ozempic labels. Tirzepatide is still studying these conditions.
Side effects
The side effect profiles are similar — both are GLP-1 class drugs, so gastrointestinal effects dominate. Nausea, vomiting, diarrhoea, and constipation are the most common, typically worst during dose escalation (Rubino et al., 2025).
Some practical differences:
- Wegovy HD 7.2mg introduced reports of dysaesthesia (altered skin sensation) that weren't common at lower doses. Generally resolves without treatment.
- Zepbound may produce slightly more diarrhoea and slightly less nausea than Wegovy for some individuals, though this varies widely between people.
- Both carry rare risks of pancreatitis, gallbladder problems, and a theoretical thyroid tumour risk (animal studies only).
If one medication's side effects are intolerable, switching to the other often works. The molecules are different enough that your body may respond differently.
Cost in 2026
This is changing fast.
Wegovy pill: $149-$299/month cash pay — by far the most affordable branded GLP-1 option.
Wegovy injection: ~$1,300/month list price, with discount programmes bringing some patients to $245/month following government-negotiated agreements.
Wegovy HD: Pricing details to come with April 2026 launch, expected to be in line with existing Wegovy injection pricing.
Zepbound: ~$1,000-1,100/month list price. Eli Lilly offers the LillyDirect programme and has matched some competitive pricing.
The generic factor: Semaglutide's patent expiry means generic Wegovy alternatives could appear in 2026-2027, potentially bringing prices down to $250-$600 initially and lower over time. Zepbound has no generic competition on the horizon.
For people paying cash, Wegovy (especially the pill) is substantially more affordable. For people with good insurance coverage, the cost difference may be negligible.
Which one should you discuss with your doctor?
Wegovy makes more sense if:
- You prefer a pill over injections
- You have cardiovascular disease (the SELECT trial indication is unique)
- Cost is a significant factor (the pill is cheapest; generics are coming)
- You have fatty liver disease or kidney disease
- You want the most formulation flexibility (three injection doses plus a pill)
Zepbound makes more sense if:
- Maximum weight loss at standard doses is the priority
- You have obstructive sleep apnoea
- You haven't responded adequately to semaglutide
- Your insurance covers it well regardless of cost
The nuanced answer: If your doctor is willing to prescribe Wegovy HD 7.2mg and you can tolerate the dose escalation, the weight loss results are comparable to Zepbound. The "Zepbound produces more weight loss" narrative, while true at standard doses, is no longer true at maximum available doses.
The best medication is the one that works for your body, fits your budget, and you'll actually take consistently. Both are exceptional tools.
Key Studies & References
We base this guide on the strongest available peer-reviewed research so you can see exactly where the information comes from.
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Wilding et al. (2021) — The STEP 1 trial: 14.9% mean weight loss with semaglutide 2.4mg over 68 weeks, the landmark study behind Wegovy's original approval. Read the full study
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Wharton et al. (2025) — The STEP UP trial: semaglutide 7.2mg (Wegovy HD) achieved 20.7% mean weight loss at 72 weeks, with one-third of participants losing ≥25%. Read the full study
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Wharton et al. (2024) — The OASIS 4 trial: oral semaglutide 25mg (Wegovy pill) achieved 16.6% mean weight loss at 64 weeks, establishing the efficacy of the pill formulation. Read the full study
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Jastreboff et al. (2022) — The SURMOUNT-1 trial: tirzepatide 15mg (Zepbound) achieved 22.5% mean weight loss at 72 weeks, with over one-third losing ≥25%. Read the full study
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Aronne et al. (2025) — The SURMOUNT-5 head-to-head trial: tirzepatide 15mg vs semaglutide 2.4mg directly compared, with 20.2% vs 13.7% weight loss favouring tirzepatide. Read the full study
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Lincoff et al. (2023) — The SELECT trial: semaglutide 2.4mg reduced major cardiovascular events by 20% in adults with obesity — the study behind Wegovy's unique cardiac indication. Read the full study