Foundayo side effects: rates by dose and when to get help
By Iacob Pastina, independent researcher & publisher · Updated September 9, 2026
Nausea, constipation, diarrhea and vomiting are common reported Foundayo side effects. The figures vary by dose; they are trial averages, not a forecast for you. Use the table to check the dose and placebo context, then take persistent or severe symptoms to your prescriber. Read the prescribing information.
Which symptoms need medical help now?
- For breathing difficulty, throat swelling or collapse, call 911.
- Stop Foundayo and contact a clinician immediately for severe abdominal pain that does not go away, with or without vomiting; pain may reach the back.
- Contact your clinician promptly for persistent vomiting or diarrhea, trouble keeping fluids down, upper abdominal pain with fever or jaundice, or vision changes.
- With insulin or a sulfonylurea, discuss low-blood-sugar precautions. Severe confusion, fainting or seizures require emergency help.
These are selected warnings, not a complete list. Read the official patient safety information. Do not wait for a fixed number of hours before asking for help.
How common were side effects in the trials?
Table 1 of the July 2026 label pools two trials in adults with obesity or overweight, with or without type 2 diabetes. Columns use the commercial tablet-equivalent strengths reported in the label. Source and full table.
| 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% |
| Abdominal pain | 7% | 13% | 14% | 14% |
| Headache | 7% | 8% | 9% | 9% |
| Fatigue | 4% | 6% | 7% | 9% |
| Hair loss | 2% | 4% | 4% | 5% |
A trial percentage is not a symptom calendar or a personal risk score. This selected table does not cover every adverse event. Separate trials cannot establish which drug is safest for you.
How do dose changes and other medicines affect the discussion?
The label starts at 0.8 mg daily, with at least 30 days before each increase. Higher strengths depend on response and tolerability; reaching the maximum is not automatic. Foundayo can be taken with or without food. Bring your medication list: interactions can change the allowed dose, and oral contraceptive precautions apply after starting and increasing treatment. Check the label instructions.
What should you bring to the prescriber conversation?
Use this editorial checklist alongside the patient safety information. It helps organize your questions; it does not diagnose a reaction.
- Record the exact product, tablet strength, start date and last dose change.
- Describe the symptom, when it began, and whether eating, drinking or daily activities are affected.
- List other medicines and supplements. Ask what needs review before the next dose change.
The boxed thyroid warning and contraindications remain important. Discuss personal or family medullary thyroid cancer or MEN 2 with your prescriber. Review all warnings.
Informational reference, not medical advice. Drafted with AI assistance and checked against the cited sources; no clinician review is claimed. Your prescriber should assess your symptoms and treatment.