Nausea, Constipation and Worse: The Stomach Side Effects of Weight-Loss Shots
Bloating & DigestionArticleStomach side effects are the most common reason weight-loss injections feel rough. In semaglutide's weight-loss trials, 73% of people had digestive side effects versus 47% on placebo, mostly while the dose was going up. The label also warns about rarer but serious problems: pancreatitis, gallbladder disease, bowel blockage and risks during sedation.
In this article
Weight-loss injections like semaglutide slow how fast your stomach empties.1 Here’s what the label reports about stomach side effects, from common to rare.
How common are stomach side effects?
In semaglutide’s weight-loss trials:1
| Side effect | Semaglutide | Placebo |
|---|---|---|
| Any digestive side effect | 73% | 47% |
| Nausea | 44% | 16% |
| Diarrhea | 30% | 16% |
| Vomiting | 25% | 6% |
| Severe digestive side effects | 4.1% | 0.9% |
Indigestion, belly pain, bloating, burping, gas, reflux, hemorrhoids and hiccups were also more common.1 Most problems showed up while the dose was being increased.1
Rarer but serious problems on the label
- Pancreatitis: stop and seek care if it’s suspected.1
- Gallbladder disease, including gallstones.1 Our guide to gallstone treatment questions covers next steps.
- Bowel blockage, ileus and severe constipation with impacted stool, reported after approval.1
- Dehydration-related kidney injury from vomiting or diarrhea.1
- Severe gastroparesis: the drug isn’t recommended if you already have it.1
- Sedation risk: tell anyone doing surgery or an endoscopy that you take it.1
- Other pills: slower stomach emptying may affect how some oral medicines are absorbed.1
Checklist: call your prescriber if…
- You can’t keep fluids down or you’re getting dizzy and peeing less
- You have severe belly pain, especially spreading to your back
- You haven’t had a bowel movement or passed gas and your belly is swelling
- You notice yellow skin or eyes, or pain under your right ribs after meals
- Side effects make it hard to eat enough
Questions to ask
- Can we slow the dose increases if side effects are rough?
- What should I do for constipation? See our guide to the laxative aisle.
- Do any of my other pills need monitoring because of slower stomach emptying?
Our articles on tirzepatide for sleep apnea, weight loss after menopause and compounded versions cover related questions.
Try: “I’ve been nauseated and constipated since my last dose increase. Can we hold the dose, and what should I use for the constipation?”
Bloated by Dinner includes a Belly Clock log and a Test-It list with a visit script. Use them to track nausea, bowel movements and meals after each dose change. See the book.
This article is for general educational purposes only and is not medical advice. It isn't a substitute for diagnosis or treatment from a qualified healthcare professional who knows your health history. Please don't change your dose or stop without talking to your prescriber. Severe belly pain that may spread to the back, persistent vomiting, inability to keep fluids down, no bowel movement or gas with a swollen belly, yellowing skin or eyes, or signs of dehydration need prompt medical care. If you think you may be having a medical emergency, call 911 or your local emergency number right away. This article discusses a prescription medicine's label. Girl Playbook does not endorse any specific product, test, or provider.
Girl Playbook sells this book. It provides education and worksheets, not individualized medical care.
Sources
The research behind this article, in the order it’s cited. How we source our articles.
- DailyMed, National Library of MedicineSemaglutide injection (weight management): prescribing information (opens in a new tab)abcdefghijk
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