Foundayo (Orforglipron) vs Zepbound: Weight Loss, Regain
Zepbound (tirzepatide) and orforglipron are both GLP-1 medicines, weekly injection versus daily tablet. In their own trials, average weight loss was 20.9% and 11.1%. Self-pay starts at $299 per month for Zepbound and $149 per month for Orforglipron.
Foundayo and Zepbound at a glance
Orforglipron and Zepbound side by side
| Zepbound | Orforglipron | |
|---|---|---|
| Medicine | Zepbound |  orforglipron |
| Active ingredient | tirzepatide | orforglipron |
| Manufacturer | Eli Lilly | Eli Lilly |
| How it is taken | Weekly injection | Daily tablet |
| Approved for | Weight loss and sleep apnea | Weight loss |
| First FDA approval | 2023 | 2026 |
| Average weight loss in trials | 20.9% (SURMOUNT-1, 72 weeks) | 11.1% (ATTAIN-1, 72 weeks) |
| Most common side effect | Nausea 29% vs 8% on placebo | Nausea 35% vs 10% on placebo |
| List price | $499 to $1,086 per fill | $649 per month |
| Self-pay from | $299 per month | $149 per month |
| Medicare GLP-1 Bridge | $50 per month, eligible Part D | $50 per month, eligible Part D |
| FDA shortage | Resolved December 19, 2024 | Not listed |
Sources: FDA label, FDA label (DailyMed), pricinginfo.lilly.com, TrumpRx.
Weight loss compared
These results are from separate trials with differing participants and durations, since the drugs have not been compared with each other in a trial.
| Trial | Who took part | Length | Group | Average weight loss | Placebo |
|---|---|---|---|---|---|
| SURMOUNT-1 | Adults with obesity or overweight, without diabetes | 72 weeks | Tirzepatide 5 mg weekly | 15% | 3.1% |
| SURMOUNT-1 | Adults with obesity or overweight, without diabetes | 72 weeks | Tirzepatide 10 mg weekly | 19.5% | 3.1% |
| SURMOUNT-1 | Adults with obesity or overweight, without diabetes | 72 weeks | Tirzepatide 15 mg weekly | 20.9% | 3.1% |
| SURMOUNT-2 | Adults who had type 2 diabetes and also had obesity or were overweight | 72 weeks | Tirzepatide 10 mg weekly | 12.8% | 3.2% |
| SURMOUNT-2 | Adults who had type 2 diabetes and also had obesity or were overweight | 72 weeks | Tirzepatide 15 mg weekly | 14.7% | 3.2% |
| ATTAIN-1 | Adults with obesity or overweight, without diabetes | 72 weeks | Foundayo 5.5 mg daily | 7.4% | 2.1% |
| ATTAIN-1 | Adults with obesity or overweight, without diabetes | 72 weeks | Foundayo 9 mg daily | 8.3% | 2.1% |
| ATTAIN-1 | Adults with obesity or overweight, without diabetes | 72 weeks | Foundayo 17.2 mg daily | 11.1% | 2.1% |
| ATTAIN-2 | Adults who had type 2 diabetes and also had obesity or were overweight | 72 weeks | Foundayo 5.5 mg daily | 5.1% | 2.5% |
| ATTAIN-2 | Adults who had type 2 diabetes and also had obesity or were overweight | 72 weeks | Foundayo 9 mg daily | 7% | 2.5% |
| ATTAIN-2 | Adults who had type 2 diabetes and also had obesity or were overweight | 72 weeks | Foundayo 17.2 mg daily | 9.6% | 2.5% |
Sources for each trial: ATTAIN-1 (FDA label (DailyMed)), SURMOUNT-2 (PubMed), SURMOUNT-1 (FDA label (DailyMed)).
Side effects compared
Each drug's label tested one group against a different placebo group, so start by comparing each drug with its own placebo.
| Side effect | Zepbound | Placebo (Zepbound trials) | Foundayo | Placebo (Foundayo trials) |
|---|---|---|---|---|
| Nausea | 29% | 8% | 35% | 10% |
| Diarrhea | 23% | 8% | 25% | 11% |
| Constipation | 17% | 5% | 27% | 9% |
| Vomiting | 13% | 2% | 24% | 4% |
| Abdominal Pain | 10% | 5% | 14% | 7% |
| Dyspepsia | 10% | 4% | 16% | 4% |
| Injection Site Reactions | 8% | 2% | Not listed | Not listed |
| Fatigue | 7% | 3% | Not listed | Not listed |
| Headache | Not listed | Not listed | 9% | 7% |
| Abdominal distension | Not listed | Not listed | 9% | 3% |
Price and coverage compared
| Medicine | How you pay | Price |
|---|---|---|
| Zepbound | List price before insurance | $499 to $1,086 per fill |
| Zepbound | Zepbound Savings Program (insured) | from $25 for up to a 3-month fill |
| Zepbound | Commercial plan that does not cover it | $299 per month |
| Zepbound | Self-pay: LillyDirect vial or KwikPen 2.5 mg | $299 per month |
| Zepbound | Self-pay: LillyDirect vial or KwikPen 5 mg | $399 per month |
| Zepbound | Self-pay: LillyDirect amounts from 7.5 mg to 15 mg, with refills within 45 days | $449 per month |
| Zepbound | Self-pay: the standard price applies if no refill happens within 45 days | $499 per month ($7.5 mg), or $699 per month ($10 to $15 mg) |
| Zepbound | Self-pay via TrumpRx | $299 per month |
| Zepbound | Medicare GLP-1 Bridge (Zepbound KwikPen, eligible Part D) | $50 per month |
| Foundayo | List price before insurance | $649 per month |
| Foundayo | Foundayo Savings Card (insured) | from $25 per month |
| Foundayo | Self-pay: LillyDirect 0.8 mg and 2.5 mg | $149 per month |
| Foundayo | Self-pay: LillyDirect 5.5 mg | $199 per month |
| Foundayo | Self-pay: LillyDirect 9 mg | $299 per month |
| Foundayo | Self-pay: LillyDirect 14.5 mg and 17.2 mg, with a refill within 45 days | $299 per month |
| Foundayo | Medicare GLP-1 Bridge (Foundayo, eligible Part D) | $50 per month |
Prices checked November 2026 (8)
pricinginfo.lilly.com 1 2, zepbound.lilly.com, Eli Lilly 1 2, TrumpRx, CMS, foundayo.lilly.com.
Who should pick which?
- No needles: Orforglipron comes as a tablet, while Zepbound is a weekly injection.
- Sleep apnea: Zepbound has approval to treat it.
- Paying cash: The lower starting price is $149 per month for Orforglipron.
Your prescriber reviews your health history, other medicines and coverage before deciding whether you should switch between them.