GLP-1 Weight Loss Statistics: The 2026 Numbers That Matter

TL;DR: In 2026, about 1 in 8 US adults has taken a GLP-1, and the newest drug in trials helped 45% of people lose more than 30% of their body weight. But the most important number is quieter: most people stop taking these medications within a year. Here is what the data actually says.

The GLP-1 story is usually told in headlines about weight loss percentages. Those numbers are real, and they keep climbing. But underneath them sits a second set of numbers — about who starts, who stays, and who quietly stops — that gets far less attention and matters far more to how your own journey turns out.

We pulled together the figures worth knowing in 2026, each linked to its primary source. Read the efficacy stats with curiosity. Read the persistence stats with care.

Key Takeaways

1. About 1 in 8 US adults (12%) report having used a GLP-1 drug, and roughly 6% — over 15 million people — are currently taking one, per KFF polling.
2. Among adults with diagnosed diabetes, 26.5% used a GLP-1 injectable in 2024, according to the CDC's National Center for Health Statistics.
3. Semaglutide (Wegovy) produced 14.9% mean weight loss at 68 weeks in the STEP 1 trial.
4. Tirzepatide (Zepbound) reached up to 20.9% at 72 weeks in SURMOUNT-1.
5. CagriSema delivered 22.7% mean reduction in REDEFINE 1, published in NEJM.
6. Retatrutide, the experimental "triple agonist," hit roughly 25% (treatment-regimen estimand) to 28% (efficacy estimand) at 80 weeks in the Phase 3 TRIUMPH-1 study.
7. In that same trial, 45.3% of people on the highest dose lost more than 30% of their body weight — a range usually associated with bariatric surgery.
8. But 46.5% of people with type 2 diabetes and 64.8% without it discontinued their GLP-1 within one year, in a cohort of 125,474 patients (JAMA Network Open).
9. A 2025 ICER analysis found that only 14.3% of patients were still on therapy at the end of two years.
10. Persistence is improving, though: one-year persistence on semaglutide for weight loss rose from 33.2% to 58.6% between 2021 and mid-2024, per the Journal of Managed Care & Specialty Pharmacy.

How many people are actually on GLP-1s

The category has moved from novelty to normal. KFF's tracking polls put lifetime use at roughly 1 in 8 adults, with about 6% currently taking one — translating to more than 15 million Americans at any given moment.

Usage is densest where the clinical need is oldest: the CDC reports that more than a quarter of adults with diagnosed diabetes (26.5%) were on a GLP-1 injectable in 2024. The weight-management wave is newer, larger in absolute terms, and far more exposed to the persistence problem below — because diabetes gives people a reason to stay that the scale alone often does not.

How much weight people actually lose

Each new molecule has nudged the ceiling higher. The trajectory, drug by drug:

• Semaglutide (Wegovy): 14.9% mean reduction at 68 weeks (STEP 1).
• Tirzepatide (Zepbound): up to 20.9% at 72 weeks (SURMOUNT-1).
• CagriSema: 22.7% in REDEFINE 1.
• Retatrutide: 24.2% at 48 weeks in its Phase 2 NEJM trial, now confirmed and extended in Phase 3.

A useful reality check: these are mean figures from controlled trials, where participants get structured support most people never receive. Your number will sit somewhere in a wide distribution around the average — and the support you build around the medication is part of what decides where.

The new frontier: retatrutide's Phase 3 numbers

The biggest data drop of 2026 came from TRIUMPH-1 (NCT05929066), the Phase 3 test of Eli Lilly's triple agonist. At 80 weeks, the dose-response was steep: 17.6% mean weight loss on 4mg, 23.7% on 9mg, and roughly 25–28% on 12mg depending on which estimand you read, versus 3.9% on placebo.

The headline that traveled: 45.3% of people on the high dose lost more than 30% of their body weight — territory previously reserved for surgery. The asterisk that traveled less: 11.3% of the high-dose group discontinued because of side effects, versus 4.9% on placebo, which has analysts debating whether the drug's tolerability will confine it to higher-BMI patients. More potent is not automatically more livable.

The persistence gap — the number nobody frames

Here is where the story turns. The efficacy numbers describe what is possible under trial conditions. The persistence numbers describe what happens in real life — and they are sobering.

In a cohort of 125,474 patients, JAMA Network Open found 46.5% of people with type 2 diabetes and 64.8% of those without diabetes discontinued within a year. A separate analysis cited by EBRI (Do et al., 2024) found 26% stopped within three months and 36% within a year. The ICER white paper extended the window: just 14.3% were still on therapy at two years.

There is one genuinely hopeful trend buried in here. Per the Journal of Managed Care & Specialty Pharmacy, one-year persistence on semaglutide for weight loss climbed from 33.2% in 2021 to 58.6% by mid-2024 — as supply stabilized and people learned what to expect. Persistence, in other words, is not fixed. It responds to support.

What this means for your journey

Put the two sets of numbers next to each other and the lesson is plain: the medication supplies the biology, but the outcome depends on staying long enough to let the biology work. A drug that delivers 25% in a trial delivers nothing if you are part of the majority who stops at month nine.

That gap is the whole reason GLP-1s feel different from anything before — and also why so many people end up back where they started. The medication quiets the food noise and resets appetite, but the window it opens is for building something — the habits, the identity, the routines that keep going when the prescription pauses. We wrote about why 53.6% of users quit and what it takes to build habits that outlast the prescription precisely because the statistics above are not destiny.

If you want to see where you might land on the efficacy curve, our weight-loss projection tool maps the published trial averages onto your own starting point — with the honest caveat that the average is a starting assumption, not a promise.

Methodology notes

• Sources: We prioritized peer-reviewed journals (NEJM, JAMA Network Open, JMCP), federal data (CDC NCHS), and independent analyses (KFF, ICER). Where a Phase 3 result has been announced but not yet published in full (retatrutide TRIUMPH-1), we linked the most detailed available reporting and labeled the figures as topline.
• Estimands: Modern obesity trials report two numbers — a "treatment-regimen" estimand (counts everyone, including those who stopped) and an "efficacy" estimand (those who stayed on treatment). We flagged both for retatrutide because the spread is meaningful and frequently conflated in coverage.
• Last reviewed: May 28, 2026.

This article covers research on GLP-1 medications. It is not medical advice. For questions about your own medication, talk to your prescriber.

Sources

1. KFF Health Tracking Poll — GLP-1 use: https://www.kff.org/health-costs/kff-health-tracking-poll-may-2024-the-publics-use-and-views-of-glp-1-drugs/
2. CDC NCHS Data Brief 537 — GLP-1 use among adults with diabetes: https://www.cdc.gov/nchs/products/databriefs/db537.htm
3. STEP 1 (semaglutide), NEJM: https://www.nejm.org/doi/full/10.1056/NEJMoa2032183
4. SURMOUNT-1 (tirzepatide), NEJM: https://www.nejm.org/doi/full/10.1056/NEJMoa2206038
5. REDEFINE 1 (CagriSema), NEJM: https://www.nejm.org/doi/full/10.1056/NEJMoa2502081
6. Retatrutide Phase 2, NEJM: https://www.nejm.org/doi/full/10.1056/NEJMoa2301972
7. Retatrutide TRIUMPH-1 Phase 3 reporting: https://www.clinicaltrialsarena.com/news/eli-lilly-retatrutide-phase-iii-triumph-1-study-results/
8. Discontinuation cohort (n=125,474), JAMA Network Open: https://pmc.ncbi.nlm.nih.gov/articles/PMC11786232/
9. ICER white paper on affordable access: https://icer.org/wp-content/uploads/2025/04/Affordable-Access-to-GLP-1-Obesity-Medications-_-ICER-White-Paper-_-04.09.2025.pdf
10. One-year persistence trend, JMCP: https://www.jmcp.org/doi/10.18553/jmcp.2026.32.3.281
11. GLP-1 coverage simulation (Do et al., 2024), EBRI: https://www.ebri.org/content/full/glp-1-coverage-and-its-impact-on-employment-based-health-plan-premiums--a-simulation-based-analysis

Frequently asked questions

What is the average weight loss on GLP-1 medications? It depends on the drug. In pivotal trials, mean weight loss ranged from about 15% on semaglutide (Wegovy) to around 21% on tirzepatide (Zepbound), 22.7% on CagriSema, and roughly 25–28% on the experimental retatrutide. Real-world results are usually lower than trial averages, largely because of how many people stop early.

Which GLP-1 causes the most weight loss in 2026? Among trial data, retatrutide currently shows the highest mean weight loss — roughly 25–28% at 80 weeks, with 45% of high-dose participants losing more than 30%. It is still experimental and not yet approved, and its side-effect discontinuation rate was higher than placebo.

How many people stop taking GLP-1s? Studies consistently show high discontinuation: roughly 46–65% within one year depending on the population, and only about 14% still on therapy at two years in one analysis. Persistence has been improving as supply and support stabilize.

Why do so many people quit GLP-1 medications? Cost, side effects, supply gaps, and the absence of a support system are the most cited reasons. Because the medication's benefit depends on staying on it, the gap between trial efficacy and real-world results is mostly a persistence gap — which is why building durable habits alongside the medication matters so much.