Most GLP-1 side effects come from the same place the benefit does: your stomach empties more slowly. That one mechanism explains the nausea, the early fullness, the constipation, and the reflux. It also explains the timing — side effects are usually worst in the first days after starting or raising a dose, then ease as your gut adapts. Knowing that pattern is half of managing it: the rough patch after a titration step is expected and usually temporary.
Nausea — the most common one
Nausea affects a large share of people, especially early. What actually helps:
- Eat smaller portions, and stop before full. Your stomach is emptying slowly; overfilling it is the fastest route to feeling sick. Listen to the "I'm done" signal — it now arrives earlier.
- Go easy on fatty, fried, and very rich foods. They sit heaviest and take longest to clear.
- Eat slowly. Speed overwhelms a slow stomach.
- Don't lie down right after eating. Let gravity help.
- If your prescriber approves, anti-nausea medication (such as ondansetron/Zofran) can bridge the worst stretch after a dose increase.
If nausea is severe, or you're vomiting repeatedly and can't keep fluids down, that's not a "push through it" situation — call your doctor.
Constipation — the quiet one
Slower digestion plus eating (and drinking) less adds up to constipation for many people. It's manageable:
- Hydrate deliberately. Appetite suppression blunts thirst too, so fluids drop right when you need more of them. This is the single biggest lever — see the dedicated hydration guide.
- Get fiber in from vegetables, fruit, legumes, whole grains — or a supplement if food alone falls short on a small appetite.
- Move. Even a daily walk helps your gut move things along.
- Ask your prescriber about a gentle stool softener or laxative if it persists.