Zepbound® vs Foundayo®
A high-efficacy weekly injection vs an oral GLP-1 pill with no food or timing restrictions. Both made by Eli Lilly — very different approaches.
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22.5%
Avg weight loss Zepbound*
From
$299/mo
Zepbound
June 2026
12.4%
Avg weight loss Foundayo*
From
$149/mo
Foundayo
June 2026
What are they?
Both come from Eli Lilly, but Zepbound uses injectable tirzepatide with a dual GIP/GLP-1 mechanism, while Foundayo is a daily oral orforglipron pill.
Zepbound
Weight ManagementFDA-approved for chronic weight management in adults with obesity (BMI 30+) or overweight (BMI 27+) with at least one weight-related condition. Uses the same dual GIP/GLP-1 mechanism as Mounjaro at equivalent doses.
Maker
Eli Lilly
Approved
2024
Format
Weekly injection
Max dose
15 mg
Foundayo
Weight ManagementFDA-approved oral GLP-1 receptor agonist for chronic weight management — the first weight-loss pill that can be taken at any time of day with no food or water restrictions. Made by Eli Lilly, approved April 2026.
Maker
Eli Lilly
Approved
2026
Format
Daily oral pill
Max dose
17.2 mg
Quick comparison
How they stack up on the metrics that matter most.
| Feature | Zepbound | Foundayo |
|---|---|---|
| Active ingredient | Tirzepatide | Orforglipron |
| FDA approved for | Weight Management | Weight Management |
| Avg weight loss | 22.5%† | 12.4%† |
| Administration | Weekly injection | Daily oral pill |
| Insurance | Limited | Limited |
| Monthly Price | From $299/mo | From $149/mo |
Zepbound
Tirzepatide
Foundayo
Orforglipron
Zepbound
Weight Management
Foundayo
Weight Management
Zepbound
22.5%†
Foundayo
12.4%†
Zepbound
Weekly injection
Foundayo
Daily oral pill
Zepbound
Limited
Foundayo
Limited
Zepbound
From $299/mo
Foundayo
From $149/mo
† Average weight loss data: Zepbound — SURMOUNT-1 (tirzepatide 15 mg, 72 weeks); Foundayo — ATTAIN-1 (oral orforglipron 36 mg, 72 weeks).
More energy,
less weight
How you ramp up
Both medications use a gradual dose escalation to minimize side effects.
Zepbound
- 1
2.5 mg
Weeks 1–4
- 2
5 mg
Weeks 5–8
- 3
7.5 mg
Weeks 9–12
- 4
10 mg
Weeks 13–16
- 5
12.5 mg
Weeks 17–20
- 6
15 mg
Weeks 21+
(Maintenance)
Foundayo
- 1
0.8 mg
Month 1
(Daily)
- 2
2.5 mg
Month 2
(Daily)
- 3
5.5 mg
Month 3
(Daily)
- 4
9 mg
Month 4
(Daily)
- 5
14.5 mg
Month 5
(Daily)
- 6
17.2 mg
Month 6+
(Maintenance)
Start your weight‑loss
journey today
Weight loss compared
Clinical trial data showing average body weight reduction over 72 weeks.
Zepbound (15 mg)
Foundayo (17.2 mg)
† Average weight loss data: Zepbound — SURMOUNT-1 (tirzepatide 15 mg, 72 weeks); Foundayo — ATTAIN-1 (oral orforglipron 36 mg, 72 weeks).
What to expect
How they stack up on the metrics that matter most.
| Side Effect | Zepbound (15 mg) | Foundayo (36 mg) |
|---|---|---|
| Nausea | 28% | ~33.7% |
| Diarrhea | 23% | ~23.1% |
| Vomiting | 13% | ~24.0% |
| Constipation | 11% | ~25.4% |
| Headache | N/A | ~9% |
| Fatigue | 7% | ~9% |
Zepbound (15 mg)
28%
Foundayo (36 mg)
~33.7%
Zepbound (15 mg)
23%
Foundayo (36 mg)
~23.1%
Zepbound (15 mg)
13%
Foundayo (36 mg)
~24.0%
Zepbound (15 mg)
11%
Foundayo (36 mg)
~25.4%
Zepbound (15 mg)
N/A
Foundayo (36 mg)
~9%
Zepbound (15 mg)
7%
Foundayo (36 mg)
~9%
Side effects may be more noticeable during dose escalation, but individual experiences vary and some risks can be serious. GLP-1 medications are not appropriate for everyone. Review important warnings, contraindications, and the FDA label or Medication Guide with a licensed healthcare provider before starting or switching treatment.
The bottom line
Branded GLP-1 medications can offer effective weight loss, requiring individualized risk-benefit clinical evaluation.
Two different GLP-1 options
- Zepbound is FDA-approved for chronic weight management in eligible adults and has shown substantial average weight loss in clinical trials, with weekly dosing and medical supervision.
- Foundayo is an oral GLP-1 medication FDA-approved for chronic weight management in eligible adults. It is taken once daily and may be suitable for patients who prefer an oral option to injectables.
Providers may pay BestGLP1 a referral fee. We disclose this for FTC compliance; rankings remain editorial.
What you
need to know
In their respective pivotal trials, Zepbound (tirzepatide 15 mg, SURMOUNT-1) showed about 22.5% average body-weight reduction over 72 weeks, compared with about 12.4% for Foundayo (orforglipron, ATTAIN-1). These are separate trials with different populations, not a head-to-head study.
Yes, switching is possible with provider guidance. Most patients see lower outcomes after moving from Zepbound to Foundayo because tirzepatide is more potent, so providers will reset expectations and titrate Foundayo carefully.
Tirzepatide activates both GIP and GLP-1 receptors via weekly injection, while orforglipron is an oral GLP-1-only pill. Tirzepatide produces roughly double the average weight loss in trials, but orforglipron offers the convenience of a daily tablet with no food or water restrictions.
Yes. Eli Lilly distributes Foundayo through LillyDirect alongside Zepbound, giving patients a direct-to-consumer fulfillment option. Pricing and eligibility vary — check the LillyDirect site for the latest cash-pay rates.
Yes. Both Zepbound and Foundayo require a prescription from a licensed healthcare provider. A consultation is required to assess whether treatment is appropriate for you.
- Zepbound (tirzepatide 5/10/15 mg). Trial: SURMOUNT-1 (2,539 participants, 72 weeks, adults with obesity/overweight without Type 2 Diabetes). Average weight loss by dose: 5 mg: −16.0%, 10 mg: −21.4%, 15 mg: −22.5% vs −2.4% placebo. Jastreboff et al., NEJM 2022.
- Foundayo (orforglipron, 36 mg capsule / 17.2 mg tablet equivalent). Trial: ATTAIN-1 (3,127 participants, 72 weeks, adults with obesity or overweight without diabetes). Average weight loss: ~12.4% vs 0.9% placebo.
BestGLP1 publishes these guides for informational and comparison purposes only. The information on this site is not medical advice, diagnosis, or treatment, and is not a substitute for guidance from a licensed healthcare professional. GLP-1 medications must be prescribed and monitored by a qualified provider; consult your provider to determine whether treatment is appropriate for your individual circumstances. Prices, side-effect rates, and clinical figures shown here are general references drawn from manufacturer labelling and published trials, and may not reflect your specific situation.
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Providers may pay BestGLP1 a referral fee. We disclose this for FTC compliance; rankings remain editorial.