Metamucil
Psyllium fiber supplement in powder, capsule, and wafer forms.
Why it helps on a GLP-1: Constipation is a common GLP-1 side effect; fiber plus plenty of fluid is a usual first step. Ask your prescriber which option suits you.
Side effects
GLP-1 constipation: why it happens and what helps
The short answer
Constipation affects roughly 1 in 5 to 1 in 4 people on GLP-1 weight-loss medicines in clinical trials—about double the placebo rate. The first steps are adding fiber gradually toward the 22–34 g a day NIH recommends, drinking enough fluids, and moving more; ask your prescriber or pharmacist before using a laxative or fiber supplement regularly. Severe belly pain, or no bowel movement with vomiting, needs prompt medical attention.
This guide is educational and not medical advice. It does not give dosing instructions. Talk to your prescriber or pharmacist about your own situation.
How common is constipation on GLP-1 medicines?
| Medicine (trial dose) | Constipation on drug | On placebo |
|---|---|---|
| Wegovy injection 2.4 mg | 24% | 11% |
| Zepbound 5 / 10 / 15 mg | 17% / 14% / 11% | 5% |
| Foundayo 5.5 / 9 / 17.2 mg | 20% / 27% / 24% | 9% |
Figures are from each medicine’s FDA-approved prescribing information.
Why do GLP-1s cause constipation?
GLP-1 medicines slow the movement of food through your gut, and you’re usually eating and drinking less. The 2025 joint advisory adds that high-protein and high-fat foods slow stomach emptying further, which can worsen constipation, and recommends managing constipation proactively rather than waiting.
What can I eat and drink to help?
- Add fiber a little at a time. NIDDK says adults need 22–34 grams of fiber a day depending on age and sex, and recommends increasing slowly to avoid gas and bloating. Good sources include beans, whole grains, fruit with skin (apples, pears), vegetables like broccoli and carrots, and nuts.
- Try prunes or other dried fruit, which the joint advisory specifically mentions.
- Drink enough fluids. NIDDK notes liquids help fiber work and soften stools; ask your clinician how much is right for you.
- Keep moving. Regular physical activity is part of every GLP-1 plan anyway.
Which over-the-counter options are there?
NIDDK lists several types of over-the-counter constipation products a health professional may recommend for a short time:
| Type | Examples (NIDDK) |
|---|---|
| Fiber supplements | Citrucel, FiberCon, Metamucil |
| Osmotic agents | Milk of Magnesia, MiraLAX (polyethylene glycol 3350) |
| Stool softeners | Colace (docusate) |
| Lubricants | Mineral oil |
| Stimulants | Correctol, Dulcolax |
The joint advisory also mentions magnesium supplements, fiber supplements, polyethylene glycol 3350 and stool softeners as options when diet alone isn’t enough. Because people respond differently and some products aren’t right for certain conditions (such as kidney disease), ask your prescriber or pharmacist which one to use and for how long.
How fast should I add fiber?
Slowly. NIDDK advises adding fiber a little at a time to reduce gas and bloating. One approach: add one fiber-rich food every few days—oatmeal at breakfast, beans in a soup, an apple or pear with the skin—while drinking more fluids. On a GLP-1, the joint advisory also notes that high-fiber foods can aggravate nausea in the first days after starting, so many people go easy until their stomach settles, then build up.
Do protein shakes make constipation worse?
They can contribute: the joint advisory says foods high in protein or fat slow stomach emptying and can worsen constipation, sometimes requiring temporary limits. Some shakes include fiber (Ensure Max Protein lists 4 g per bottle), and pairing protein with fiber-rich foods helps balance things. Keep up fluids when protein intake rises.
Can constipation cause diarrhea on a GLP-1?
Yes. The advisory notes that extended constipation can lead to reactive diarrhea—loose stool leaking around hard stool. If you alternate between the two, tell your prescriber rather than reaching for an anti-diarrhea medicine on your own.
What about magnesium?
The joint advisory mentions daily magnesium supplementation, adjusted to keep bowel movements regular, as an option when diet isn’t enough, noting magnesium citrate is effective and well tolerated. Magnesium isn’t right for everyone—people with kidney disease in particular should ask first—so check with your prescriber or pharmacist before starting it.
What daily habits help most?
| Habit | Why |
|---|---|
| A fiber food at most meals, added gradually | NIDDK: fiber helps stools pass; slow increases limit gas |
| Fluids through the day | Helps fiber work and prevents dehydration |
| Daily movement | Part of every GLP-1 plan; supports regularity |
| Pair protein with produce or whole grains | Protein and fat slow stomach emptying (joint advisory) |
| Note bowel habits in a tracker | Shows your prescriber what’s working |
When is GLP-1 constipation an emergency?
Get medical help right away for severe stomach pain that won’t go away, a swollen or hard belly, vomiting with no bowel movement, or blood in your stool. The labels warn that GLP-1 medicines can cause severe stomach problems. Also tell your prescriber if constipation lasts despite these steps—they may adjust your plan.
Quick answers
What is the best thing to take for constipation on Ozempic or Zepbound?
Start with gradual fiber, fluids and activity. If that’s not enough, options include fiber supplements, osmotic laxatives like MiraLAX, and stool softeners. Ask your prescriber or pharmacist which suits you, since the right choice depends on your health.
Can I take MiraLAX with a GLP-1?
MiraLAX (polyethylene glycol 3350) is one of the over-the-counter options NIDDK lists, and the 2025 GLP-1 nutrition advisory mentions it. Check with your prescriber or pharmacist before using it regularly.
How much fiber should I eat on a GLP-1?
NIDDK says adults generally need 22–34 grams a day depending on age and sex. Increase slowly and drink enough fluids so the fiber works without extra bloating.
How long does GLP-1 constipation last?
It varies. Stomach side effects are often most noticeable when starting or increasing a dose. Managing it early with fiber, fluids and activity helps; tell your prescriber if it persists.
Do electrolyte drinks help constipation on a GLP-1?
Fluids of any kind help fiber work, and electrolyte drinks can help if you’re also losing fluids from vomiting or diarrhea. They aren’t a constipation treatment on their own. If you limit sodium for heart or kidney reasons, ask your clinician first.
Products & programs mentioned
Benefiber
Taste-free wheat dextrin fiber that dissolves in drinks and soft foods.
Why it helps on a GLP-1: An easy way to add fiber when you're eating less overall.
MiraLAX
Over-the-counter osmotic laxative (polyethylene glycol 3350).
Why it helps on a GLP-1: A common OTC choice for occasional constipation—check with your prescriber or pharmacist before using it regularly.
Liquid I.V.
Electrolyte drink mixes, including sugar-free options.
Why it helps on a GLP-1: Fluid losses from nausea or diarrhea can lead to dehydration; electrolyte mixes make it easier to drink up.
Ensure Max Protein
Nutrition shakes with 30g protein and 1g sugar in a 150-calorie bottle.
Why it helps on a GLP-1: Widely available at pharmacies and grocery stores; a familiar option when solid food feels like too much.
Browse related categories: 🌿 Side effects 💧 Hydration 🥤 Protein
Keep reading
Side effects
Ozempic and Zepbound nausea: what actually helps
How common nausea is on GLP-1 medicines, why it happens, eating tips from a 2025 expert advisory, helpful products, and when to call your prescriber.
Read the guide →Food & proteinWhat to eat on Zepbound or Ozempic: a 1-day high-protein plan
A realistic high-protein day of eating on a GLP-1: small meals, about 90 g protein, fiber and fluids, plus foods that tend to ease nausea. Sources cited.
Read the guide →Getting startedStarting a GLP-1: your first-month checklist
A practical, no-dosing checklist for your first month on Zepbound, Wegovy, Ozempic, Mounjaro or a GLP-1 pill: questions, cost, food, side effects.
Read the guide →Sources
- Wegovy (semaglutide) injection and tablets Prescribing Information, Novo Nordisk
- Zepbound (tirzepatide) Prescribing Information, Eli Lilly (rev. 08/2026)
- Foundayo (orforglipron) Prescribing Information, Eli Lilly (rev. 07/2026)
- Mozaffarian et al. Nutritional priorities to support GLP-1 therapy for obesity: joint advisory (ACLM, ASN, OMA, TOS), 2025
- NIDDK (NIH): Eating, Diet & Nutrition for Constipation
- NIDDK (NIH): Treatment for Constipation
Prices and program terms change often; we re-check them on the official pages listed above. Listings are not endorsements, and we never list compounded semaglutide or tirzepatide sellers. Spot something outdated? Email [email protected].
Medical disclaimer: This guide is educational and not medical advice. It does not give dosing instructions. Talk to your prescriber or pharmacist about your own situation. If you have a medical emergency, call 911. Read our full disclaimer.