Foundayo vs Zepbound: Weight Loss, Regain Data
Foundayo (orforglipron) and Zepbound (tirzepatide) are both GLP-1 medicines, daily tablet versus weekly injection. In their own trials, average weight loss was 11.1% and 20.9%. Self-pay starts at $149 per month for Foundayo and $299 per month for Zepbound.
Foundayo and Zepbound in brief
Foundayo and Zepbound compared side by side
| Foundayo | Zepbound | |
|---|---|---|
| Medicine | Foundayo |  Zepbound |
| Active ingredient | orforglipron | tirzepatide |
| Manufacturer | Eli Lilly | Eli Lilly |
| How it is taken | Daily tablet | Weekly injection |
| Approved for | Weight loss | Weight loss and sleep apnea |
| First FDA approval | 2026 | 2023 |
| Average weight loss in trials | 11.1% (ATTAIN-1, 72 weeks) | 20.9% (SURMOUNT-1, 72 weeks) |
| Most common side effect | Nausea 35% vs 10% on placebo | Nausea 29% vs 8% on placebo |
| List price | $649 per month | $499 to $1,086 per fill |
| Self-pay from | $149 per month | $299 per month |
| Medicare GLP-1 Bridge | $50 per month, eligible Part D | $50 per month, eligible Part D |
| FDA shortage | Not listed | Resolved December 19, 2024 |
Sources: FDA label, FDA label (DailyMed), pricinginfo.lilly.com, Eli Lilly.
Weight loss compared
The two drugs have not been compared directly in one trial. Their results come from separate trials with different groups and lengths.
| Trial | Who took part | Length | Group | Average weight loss | Placebo |
|---|---|---|---|---|---|
| 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 with obesity or overweight and type 2 diabetes | 72 weeks | Foundayo 5.5 mg daily | 5.1% | 2.5% |
| ATTAIN-2 | Adults with obesity or overweight and type 2 diabetes | 72 weeks | Foundayo 9 mg daily | 7% | 2.5% |
| ATTAIN-2 | Adults with obesity or overweight and type 2 diabetes | 72 weeks | Foundayo 17.2 mg daily | 9.6% | 2.5% |
| 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 with obesity or overweight and type 2 diabetes | 72 weeks | Tirzepatide 10 mg weekly | 12.8% | 3.2% |
| SURMOUNT-2 | Adults with obesity or overweight and type 2 diabetes | 72 weeks | Tirzepatide 15 mg weekly | 14.7% | 3.2% |
Trial sources: ATTAIN-1 (FDA label (DailyMed)), SURMOUNT-1 (FDA label (DailyMed)), SURMOUNT-2 (PubMed).
Side effects compared
In each label, its drug was compared with a separate placebo group, so first compare each drug against its own placebo.
| Side effect | Foundayo | Placebo (Foundayo trials) | Zepbound | Placebo (Zepbound trials) |
|---|---|---|---|---|
| Nausea | 35% | 10% | 29% | 8% |
| Constipation | 27% | 9% | 17% | 5% |
| Diarrhea | 25% | 11% | 23% | 8% |
| Vomiting | 24% | 4% | 13% | 2% |
| Dyspepsia | 16% | 4% | 10% | 4% |
| Abdominal pain | 14% | 7% | 10% | 5% |
| Headache | 9% | 7% | Not listed | Not listed |
| Abdominal distension | 9% | 3% | Not listed | Not listed |
| Injection Site Reactions | Not listed | Not listed | 8% | 2% |
| Fatigue | Not listed | Not listed | 7% | 3% |
Prices and coverage compared
| Medicine | How you pay | Price |
|---|---|---|
| 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 | Through LillyDirect for 14.5 mg doses and 17.2 mg doses, you pay the cost yourself if you refill within a 45 day window | $299 per month |
| Foundayo | Medicare GLP-1 Bridge (Foundayo, eligible Part D) | $50 per month |
| 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 7.5 mg through 15 mg, if you refill within 45 days | $449 per month |
| Zepbound | Self-pay: without a refill within 45 days, you pay the regular price | monthly price: $499 for $7.5 mg; $699 for $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 |
Prices checked November 2026 (8)
pricinginfo.lilly.com 1 2, foundayo.lilly.com, Eli Lilly 1 2, CMS, zepbound.lilly.com, TrumpRx.
Who should pick which?
- You take Foundayo as a tablet without needles; Zepbound is given by weekly injection.
- Sleep apnea: Zepbound has approval to treat it.
- For cash payments, Foundayo starts at $149 each month, which is a lower rate.
Before deciding whether you should switch, your prescriber reviews your coverage, other medicines, and health history.