Quick answer: Foundayo (orforglipron) is Eli Lilly's once-daily GLP-1 pill for weight loss, FDA-approved in April 2026; Zepbound (tirzepatide) is Lilly's once-weekly injection. No trial has compared them directly. In their own placebo-controlled trials, Foundayo's top dose averaged 11.1% weight loss at 72 weeks and Zepbound's top dose 20.9%. Foundayo starts at $149 a month self-pay through LillyDirect ($299 at 9 mg and up if refilled within 45 days; $349 otherwise at 14.5 and 17.2 mg) versus $299–$449 for Zepbound. Foundayo is taken once a day with or without food; the Wegovy pill needs an empty stomach.
Foundayo and Zepbound are both prescription weight-loss medicines from Eli Lilly, but they are different molecules in different forms. Foundayo is orforglipron, a small-molecule GLP-1 receptor agonist taken as a daily tablet; Zepbound is tirzepatide, a weekly injection that acts on both GIP and GLP-1 receptors. Searching orforglipron vs tirzepatide? It is the same comparison. The Wegovy pill (oral semaglutide) is the other weight-loss pill, so it sits in the third column.
- No head-to-head trial: Foundayo's top dose averaged 11.1% weight loss (ATTAIN-1), Zepbound's 20.9% (SURMOUNT-1) and the Wegovy pill 13.6% (OASIS 4), in separate trials.
- Self-pay at LillyDirect: Foundayo $149 to start and $299 at 9 mg and up; Zepbound $299 to start and $449 at 7.5 mg and up.
- People who switched from Zepbound to orforglipron after losing weight kept about three-quarters of their loss at one year, versus about half on placebo (ATTAIN-MAINTAIN).
Foundayo vs Zepbound at a glance (orforglipron vs tirzepatide)
| Foundayoorforglipron · Eli Lilly | Zepboundtirzepatide · Eli Lilly | Wegovy pilloral semaglutide 25 mg · Novo Nordisk | |
|---|---|---|---|
| What it is | Small-molecule (non-peptide) GLP-1 receptor agonist | Dual GIP and GLP-1 receptor agonist (peptide) | GLP-1 receptor agonist (peptide) with an absorption enhancer |
| How you take it | One tablet daily, with or without food | Injection once a week (KwikPen, vial or single-dose pen) | One tablet each morning on an empty stomach with up to 4 oz of water; wait 30 minutes before eating, drinking or other pills |
| FDA-approved for | Weight reduction and long-term maintenance in adults (Apr 1, 2026); not approved for type 2 diabetes | Weight reduction in adults; obstructive sleep apnea in adults with obesity (Dec 2024) | Weight reduction and heart-risk reduction in adults (approved Dec 2025) |
| Dose steps | 0.8 mg, then 2.5 mg, then 5.5 mg, each for at least 30 days; may step on to 9, 14.5 or 17.2 mg | 2.5 mg for 4 weeks, then up 2.5 mg at a time every 4+ weeks; maintenance 5, 10 or 15 mg | 1.5 mg, 4 mg and 9 mg, 30 days each, then 25 mg |
| Maximum dose | 17.2 mg daily (9 mg with strong CYP3A4 inhibitors) | 15 mg weekly | 25 mg daily |
| Self-pay from | $149 a month (0.8 mg) | $299 a month (2.5 mg) | $149 a month (1.5 mg) |
Orforglipron vs tirzepatide: trial results compared
Orforglipron and tirzepatide have never been tested against each other, so each column comes from that drug's own placebo-controlled trial in adults without diabetes. Foundayo's figures are from its label, which reports the trial at the equivalent marketed doses.
| Result | Foundayoorforglipron · Eli Lilly | Zepboundtirzepatide · Eli Lilly | Wegovy pilloral semaglutide 25 mg · Novo Nordisk |
|---|---|---|---|
| Average weight loss at the top doseCounting: everyone randomized, including people who stopped (treatment-regimen / treatment-policy) | 11.1%ATTAIN-1 (Foundayo label, Trial 1), 3,127 people, 72 weeks; 17.2 mg | 20.9%SURMOUNT-1, 2,539 people, 72 weeks; 15 mg | 13.6%OASIS 4, 307 people, 64 weeks; 25 mg |
| Lost 20% or more of body weight, top doseCounting: everyone randomized, including people who stopped (treatment-regimen / treatment-policy) | 18.4%ATTAIN-1 (Foundayo label, Trial 1), 3,127 people, 72 weeks; 17.2 mg | 57%SURMOUNT-1, 2,539 people, 72 weeks; 15 mg | 27.9%OASIS 4, 307 people, 64 weeks; 25 mg, per the Wegovy label |
| Placebo group in the same trialCounting: everyone randomized, including people who stopped (treatment-regimen / treatment-policy) | 2.1%ATTAIN-1 (Foundayo label, Trial 1), 3,127 people, 72 weeks | 3.1%SURMOUNT-1, 2,539 people, 72 weeks | 2.2%OASIS 4, 307 people, 64 weeks |
Percentages are average body-weight change counting everyone who started. These are separate trials with different people, lengths and placebo results, so compare the gap over placebo, not just the headline: read the columns as a ballpark, not a ranking. ATTAIN-1 published 11.2% for its 36 mg arm (NEJM 2025); the Foundayo label reports 11.1% at the equivalent 17.2 mg dose. Trial results apply to the FDA-approved branded drugs only.
Is there a head-to-head trial of Foundayo vs Zepbound?
No. Lilly has not published a trial giving people either orforglipron or tirzepatide. The closest data:
- ACHIEVE-3 compared orforglipron with oral semaglutide (Rybelsus doses, 7 and 14 mg) in 1,698 adults with type 2 diabetes for 52 weeks. Orforglipron lowered A1C more (1.71% and 1.91% vs 1.23% and 1.47%), and more people stopped it because of side effects (9–10% vs 4–5%) (Lancet 2026). Foundayo is not approved for type 2 diabetes.
- ATTAIN-MAINTAIN tested orforglipron as the next step after the injections (below).
Foundayo vs Wegovy pill: the two weight-loss pills
Both are daily GLP-1 tablets that start at $149 a month self-pay. The practical difference is the routine: the Wegovy pill (semaglutide) must be swallowed on an empty stomach with up to 4 oz of water, then nothing else for 30 minutes, while Foundayo (orforglipron) can be taken with or without food, with no fasting window. In their own trials, the Wegovy pill averaged 13.6% at 64 weeks and Foundayo 11.1% at 72 weeks; they have not been compared directly. The Wegovy pill is also approved to lower heart attack and stroke risk in adults with heart disease; Foundayo is not. Foundayo has more drug interactions to check: strong CYP3A4 inhibitors cap it at 9 mg, and its label calls for a non-oral or backup contraceptive for 30 days after starting and after each dose increase. For semaglutide's pill against its shot, see oral vs injectable semaglutide.
Foundayo or Zepbound: who each one fits
| If you… | What the labels and trials point to |
|---|---|
| Are comparing average weight loss | Higher on Zepbound: about 21% at the top dose versus about 11% for Foundayo, in separate trials |
| Don't want injections | Foundayo or the Wegovy pill |
| Can't fit an empty-stomach morning routine | Foundayo (with or without food) rather than the Wegovy pill |
| Have obstructive sleep apnea and obesity | Zepbound is the one approved for it |
| Have heart disease | The Wegovy pill (or Wegovy pen) is approved to lower heart attack and stroke risk; neither Foundayo nor Zepbound is |
| Lost weight on an injection and want to keep it off with a pill | Foundayo was tested for exactly that in ATTAIN-MAINTAIN (see switching, below) |
| Take medicines that strongly block CYP3A4 (some antifungals, HIV drugs) | Foundayo's label caps the dose at 9 mg and rules out some combinations; Zepbound has no such limit |
| Take birth-control pills | Both Foundayo (30 days) and Zepbound (4 weeks) call for a non-oral or backup method after starting and after each dose increase |
The weight-loss labels generally require a BMI of 30 or more, or 27 or more with a weight-related condition. A licensed prescriber decides which drug and dose fit you.
Foundayo vs Zepbound side effects and label warnings
All three are mostly stomach-and-gut side effects. The rates below come from each label's placebo-controlled trials, at the dose shown, so they are not a head-to-head comparison. On Foundayo, 10% of people at 17.2 mg stopped because of side effects, versus 3% on placebo (pooled label trials).
| Side effect | Foundayoorforglipron · Eli Lilly | Zepboundtirzepatide · Eli Lilly | Wegovy pilloral semaglutide 25 mg · Novo Nordisk |
|---|---|---|---|
| Nausea | 35% at 17.2 mg (placebo 10%) | 28% at 15 mg (placebo 8%) | Most common side effect |
| Other common | Constipation, diarrhea, vomiting, indigestion, stomach pain, headache, bloating, fatigue, burping, reflux, gas, hair loss | Diarrhea, vomiting, constipation, stomach pain, indigestion, injection-site reactions, fatigue, allergic reactions, burping, hair loss, reflux | Diarrhea, vomiting, constipation, stomach pain, headache, fatigue, indigestion, dizziness, bloating, burping, gas, reflux, hair loss |
All three labels carry a boxed warning about thyroid C-cell tumors and rule the drugs out for anyone with a personal or family history of medullary thyroid cancer or MEN 2 (Foundayo's label notes orforglipron is not active in rats or mice, so the rodent finding behind the warning could not be tested; it keeps the warning). Shared warnings include pancreatitis, gallbladder disease, kidney injury from dehydration, severe stomach reactions, low blood sugar with insulin or sulfonylureas, allergic reactions, diabetic eye complications and aspiration risk under anesthesia. More: Mounjaro and Zepbound side effects.
Foundayo vs Zepbound cost without insurance
Both are sold self-pay through LillyDirect, and both rise with the dose. Foundayo has a lower ceiling:
| Option | Month 1 | Usual maintenance month | First-year estimate | Source |
|---|---|---|---|---|
| Foundayo (LillyDirect) | $149 (0.8 mg) | $299 at 9 mg and up (14.5 and 17.2 mg if refilled within 45 days; $349 if later) | $3,338 | LillyDirect Foundayo |
| Zepbound vial or KwikPen (LillyDirect) | $299 (2.5 mg) | $399 at 5 mg; $449 at 7.5–15 mg if refilled within 45 days ($499–$699 if later) | $5,188 | LillyDirect Zepbound |
| Wegovy pill (NovoCare) | $149 (1.5 mg) | $299 at 9 or 25 mg | $3,338 | NovoCare Wegovy |
First-year estimates are our arithmetic from each maker's published self-pay prices, counted as 12 fills, medication only (a prescriber visit is extra). Foundayo: 0.8 mg, 2.5 mg at its regular $199, then 10 fills at 5.5 mg or higher at $299. Through Dec 31, 2026, Lilly has cut 2.5 mg to $149 and 5.5 mg to $199, which would bring a year started now to about $3,188. Zepbound: 2.5 mg, 5 mg, then 10 fills at 7.5 mg or higher refilled within 45 days; Zepbound fills last 4 weeks, so a calendar year takes 13. Wegovy pill: 1.5 mg, 4 mg, then 10 fills at 9 or 25 mg.
With insurance: Lilly's savings cards for commercially insured patients bring Foundayo or Zepbound to "as little as $25" a fill, with monthly savings caps, until Dec 31, 2026 (Foundayo terms, Zepbound terms); they don't apply to Medicare or Medicaid. Medicare: the Medicare GLP-1 Bridge charges eligible Part D members $50 a month, through Dec 31, 2027, for Foundayo, the Wegovy pen or pill, and the Zepbound KwikPen (not vials or single-dose pens). Every option side by side: GLP-1 cost comparison.
Switching from Zepbound to Foundayo
Lilly tested this in ATTAIN-MAINTAIN: 376 adults who had lost weight on Zepbound or Wegovy in SURMOUNT-5 were switched to orforglipron or a placebo pill for 52 weeks. Counting everyone randomized, those coming off Zepbound kept 74.7% of their earlier weight loss on orforglipron versus 49.2% on placebo; those coming off Wegovy kept 79.3% versus 37.6% (Nature Medicine, 2026). Nobody in the trial stayed on the injection, so it does not show how a pill compares with continuing Zepbound. The labels give no direct conversion between the two drugs; your prescriber sets the dose. Going the other way, from a semaglutide product to tirzepatide, is covered in switching from semaglutide to tirzepatide.
Related comparisons
- Zepbound vs Wegovy 2026: Price, Results & Which Fits
- Tirzepatide vs Semaglutide: 2026 Head-to-Head Update
- Oral vs injectable semaglutide
- Which GLP-1 is most effective for weight loss?
- GLP-1 cost comparison
- Zepbound vs Ozempic
- Ozempic vs Wegovy
- Mounjaro vs Ozempic
Frequently asked questions
Is Foundayo as effective as Zepbound?
Not on the trial averages: Foundayo's top dose averaged 11.1% weight loss at 72 weeks in ATTAIN-1, while Zepbound's top dose averaged 20.9% in SURMOUNT-1. The two have not been compared in the same trial.
Is orforglipron the same as tirzepatide?
No: orforglipron (Foundayo) is a small-molecule GLP-1 pill taken daily, while tirzepatide (Zepbound, Mounjaro) is a weekly injection that acts on both GIP and GLP-1 receptors. Both are made by Eli Lilly.
How much does Foundayo cost without insurance?
Through LillyDirect, Foundayo is $149 a month at 0.8 mg, $199 at 2.5 mg and $299 at 5.5 mg and 9 mg at regular prices, with 2.5 mg and 5.5 mg temporarily cut to $149 and $199 through Dec 31, 2026. The 14.5 and 17.2 mg doses are $299 if refilled within 45 days and $349 otherwise.
Foundayo vs Wegovy pill: which is better?
Neither is clearly better: the Wegovy pill averaged 13.6% weight loss in OASIS 4 and Foundayo 11.1% in ATTAIN-1, in separate trials. Foundayo can be taken with or without food, while the Wegovy pill needs an empty stomach and a 30-minute wait.
Can you switch from Zepbound to Foundayo?
Yes, with a prescription: in ATTAIN-MAINTAIN, people who switched from Zepbound to orforglipron kept about 75% of their earlier weight loss at one year, versus about 49% on placebo.
Is Foundayo approved for type 2 diabetes?
No, Foundayo is approved only for weight reduction and maintenance in adults with obesity or overweight with a weight-related condition.
Does Foundayo have to be taken on an empty stomach?
No, the Foundayo label says to take it once daily with or without food. The Wegovy pill is the one that must be taken on an empty stomach.
Sources and references
- Foundayo (orforglipron) Prescribing Information, DailyMed (Aug 2026) (accessed Oct 13, 2026)
- FDA: first new molecular entity under the national priority voucher program (Foundayo), Apr 1, 2026 (accessed Oct 13, 2026)
- Wharton S et al. Orforglipron, an Oral Small-Molecule GLP-1 Receptor Agonist for Obesity Treatment (ATTAIN-1). NEJM 2025;393:1796-1806 (accessed Oct 13, 2026)
- Aronne LJ et al. Orforglipron for maintenance of body weight reduction (ATTAIN-MAINTAIN). Nature Medicine 2026;32:2679-87 (accessed Oct 13, 2026)
- Orforglipron vs oral semaglutide in type 2 diabetes (ACHIEVE-3). Lancet 2026;407:1147-60 (accessed Oct 13, 2026)
- Jastreboff AM et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). NEJM 2022 (accessed Oct 13, 2026)
- Wharton S et al. Oral Semaglutide at a Dose of 25 mg in Adults with Overweight or Obesity (OASIS 4). NEJM 2025 (accessed Oct 13, 2026)
- Zepbound (tirzepatide) Prescribing Information, DailyMed (Sep 2026) (accessed Oct 13, 2026)
- Wegovy (semaglutide) injection and tablets, Prescribing Information, DailyMed (Jun 2026) (accessed Oct 13, 2026)
- Novo Nordisk: FDA approves the Wegovy pill, Dec 22, 2025 (accessed Oct 13, 2026)
- LillyDirect: Foundayo self-pay prices (accessed Oct 13, 2026)
- Foundayo savings and coverage (Lilly) (accessed Oct 13, 2026)
- LillyDirect: Zepbound self-pay prices (accessed Oct 13, 2026)
- Zepbound savings card and KwikPen terms (Lilly) (accessed Oct 13, 2026)
- NovoCare: Wegovy self-pay prices (pill) (accessed Oct 13, 2026)
- CMS: Medicare GLP-1 Bridge (accessed Oct 13, 2026)
This page compares published trials, FDA labels and makers' price pages; it is not medical advice, and a licensed prescriber decides which drug and dose fit you. Trial results are for the FDA-approved branded drugs only. Nouri is a publisher; it does not prescribe or sell any medication, and it is not affiliated with Eli Lilly or Novo Nordisk. Facts checked Oct 13, 2026; prices change, so confirm at the source.
Disclosure: Nouri may earn a commission when you sign up with some of the providers we link to. It doesn't change what you pay or how we rank providers. This comparison has no partner link in its text, and no drug maker paid for it. Full disclosure.
Medical Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider before starting or changing any medication or treatment. Licensed providers review patient assessments before making clinical decisions.
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