Foundayo side effects: every rate on the FDA label
Most common adverse reactions, reported in ≥5% of patients treated with FOUNDAYO, are nausea, constipation, diarrhea, vomiting, dyspepsia, abdominal pain, headache, abdominal distension, fatigue, eructation, gastroesophageal reflux disease, flatulence, and hair loss. (6.1) dailymed.nlm.nih.gov, Sep 27, 2026
Boxed warning
WARNING: RISK OF THYROID C-CELL TUMORS
dailymed.nlm.nih.gov, Sep 27, 2026In products with glucagon-like peptide-1 (GLP-1) receptor agonist activity that are pharmacologically active in rats and mice, rodent thyroid C-cell tumors (adenomas and carcinomas) have been observed at clinically relevant exposures and are considered GLP-1 receptor-dependent effects in rodents.
dailymed.nlm.nih.gov, Sep 27, 2026- Orforglipron itself did not produce tumors in rodents (not active in rats/mice).
Orforglipron is not pharmacologically active in rats or mice and did not produce tumors in rodents [see Nonclinical Toxicology (13.1)].
dailymed.nlm.nih.gov, Sep 27, 2026
How often each side effect happened
| Side effect | Placebo | 5.5 mg | 9 mg | 17.2 mg |
|---|---|---|---|---|
| Nausea | 10% | 26% | 34% | 35% |
| Constipation | 9% | 20% | 27% | 24% |
| Diarrhea | 11% | 21% | 23% | 25% |
| Vomiting | 4% | 13% | 21% | 24% |
| Dyspepsia | 4% | 12% | 16% | 13% |
| Abdominal pain | 7% | 13% | 14% | 14% |
| Headache | 7% | 8% | 9% | 9% |
| Fatigue | 4% | 6% | 7% | 9% |
| Eructation | 1% | 6% | 8% | 8% |
| Hair loss | 2% | 4% | 4% | 5% |
Percent of people in the trial who reported it. Placebo is the comparison group.
In a pool of Trials 1 and 2, dizziness was reported in 4% of FOUNDAYO-treated patients and 3% of placebo-treated patients.
dailymed.nlm.nih.gov, Sep 27, 2026
Who stopped because of side effects
- Discontinued for adverse reactions: 8% overall (6/9/10% by dose) vs 3% placebo.
Across both trials, 8% of patients treated with FOUNDAYO (5.5 mg, 6%; 9 mg, 9%; and 17.2 mg, 10%) once daily permanently discontinued treatment as a result of adverse reactions compared to 3% of patients receiving placebo.
dailymed.nlm.nih.gov, Sep 27, 2026
Who should not take it, pregnancy and breastfeeding
- Contraindicated with personal/family history of MTC or MEN 2.
A personal or family history of MTC or in patients with MEN 2 [see Warnings and Precautions (5.1)].
dailymed.nlm.nih.gov, Sep 27, 2026 - Contraindicated with known serious hypersensitivity to orforglipron or excipients.
Known serious hypersensitivity to orforglipron or any of the excipients in FOUNDAYO. Serious hypersensitivity reactions, including anaphylaxis and angioedema, have been reported with GLP-1 receptor agonists [see Warnings and Precautions (5.6), Adverse Reactions (6.2)].
dailymed.nlm.nih.gov, Sep 27, 2026 - Pregnancy: stop Foundayo when pregnancy is recognized.
Weight loss offers no benefit to a pregnant patient and may cause fetal harm. When a pregnancy is recognized, advise the pregnant patient of the risk to a fetus and discontinue FOUNDAYO.
dailymed.nlm.nih.gov, Sep 27, 2026 - Lactation: no human data.
There are no data on the presence of orforglipron or its metabolites in human milk, the effects on the breastfed infant, or the effects on milk production.
dailymed.nlm.nih.gov, Sep 27, 2026 - Not recommended while nursing.
FOUNDAYO is not recommended for nursing women.
dailymed.nlm.nih.gov, Sep 27, 2026
Label revised 7/2026: read the full label on DailyMed. The label lists more reactions and warnings than this page.
Doses and schedule: Foundayo dosing · Price: Foundayo cost · All medications: side effects compared
This page reports what the label says; it is not medical advice. Tell your prescriber about any side effect.Medical disclaimer.