Two GLP-1 pills are now FDA-approved for weight loss: the Wegovy pill (oral semaglutide, Novo Nordisk) and Foundayo (orforglipron, Eli Lilly). Both work on one hormone pathway, GLP-1, and are taken once a day. Retatrutide is a different kind of drug: a once-weekly injection that targets three receptors (GLP-1, GIP and glucagon). It is investigational and can't be prescribed outside clinical trials or Lilly's expanded access program.
The numbers, side by side
Three different trials with different populations, durations and analysis methods — not a head-to-head. All three figures below are the "treatment-regimen" (or treatment-policy) estimand, which counts everyone who started, including people who stopped treatment. Treat cross-trial gaps as indicative only.
| Wegovy pill 25 mg — OASIS 4 [1] | Foundayo top dose — ATTAIN-1 [6] | Retatrutide 12 mg — TRIUMPH-1 [9] | |
|---|---|---|---|
| Status | FDA-approved Dec 22, 2025 [4] | FDA-approved Apr 1, 2026 [5] | Investigational |
| Form | Daily tablet | Daily tablet | Weekly injection |
| Receptors | GLP-1 | GLP-1 (small molecule) | GLP-1, GIP, glucagon |
| Duration | 64 weeks | 72 weeks | 80 weeks |
| Mean weight loss | 13.6% (vs 2.2% placebo) | 11.2% (vs 2.1% placebo) | ~25.0% |
| If everyone stayed on treatment | 16.6% | 12.4% | 28.3% [8] |
Foundayo's trial used a 36 mg capsule; per Lilly that corresponds to the 17.2 mg approved tablet. [7]
Side effects
All three drugs share the incretin-class pattern: stomach side effects are the most common, especially while the dose is being stepped up.
- Wegovy pill 25 mg: nausea 46.6% vs 18.6% on placebo; vomiting 30.9% vs 5.9%; 6.9% stopped because of side effects vs 5.9%. [2]
- Foundayo 36 mg (trial dose): nausea 33.7% vs 10.4%; vomiting 24.0% vs 3.5%; diarrhea 23.1% vs 9.6%; constipation 25.4% vs 9.3%; 10.3% stopped vs 2.6%. [6]
- Retatrutide 12 mg: nausea 42.4%, vomiting 25.3%, diarrhea 32.0%, constipation 26.1%; 11.3% stopped vs 4.9% — plus a dysesthesia (skin sensation) signal covered in retatrutide side effects. [9]
How you take them
The practical difference is daily pill vs weekly shot — and the two pills differ from each other:
- Wegovy pill: on an empty stomach in the morning with up to 4 oz of plain water, then wait at least 30 minutes before eating, drinking or taking other medicines. [3]
- Foundayo: any time of day, with or without food — no food or water restrictions. [5]
- Retatrutide: studied as a once-weekly injection under the skin.
What you can actually get today
Both pills can be prescribed now; retatrutide cannot. ProjectedLilly plans to submit retatrutide to the FDA in Q1 2027 — company guidance, not a commitment. For what the approved options cost and why "cheap reta" offers are a red flag, see what retatrutide might cost. Many practices in the RetaMaps directory prescribe approved GLP-1 medications today, and Should I wait for retatrutide? covers the start-now-or-wait question to take to your clinician.
More matchups: retatrutide vs semaglutide (the injectable form of the Wegovy pill's drug), retatrutide vs tirzepatide, retatrutide vs CagriSema, retatrutide vs survodutide, or every comparison on one page: retatrutide vs other weight-loss drugs.