The short answer
For most adults on a GLP-1, the first thing to take is an osmotic: MiraLAX (polyethylene glycol 3350) or magnesium, which hold water in the stool without forcing the bowel. Add soluble fiber slowly, with water. Keep senna or bisacodyl for an occasional stuck day, within each label’s time limit. Severe belly pain, vomiting, or a swollen belly with no gas needs a call the same day.
At GLP-1 SOS, “what should I actually buy?” is the constipation question we get most, often from someone standing in the pharmacy aisle. This is the short buying guide; each option has its own page, linked below.
The order that usually works
Three steps, in this order
1
Osmotic first
MiraLAX or magnesium hold water in the stool. Nothing is pushed.
2
Fiber, carefully
Soluble fiber such as psyllium, a little at a time, with water.
3
Stimulant as rescue
Senna or bisacodyl for an occasional stuck day, not as the daily plan.
What is actually happening
A GLP-1 slows how fast food moves through your gut, and the longer stool sits in the colon, the more water the colon pulls out of it. Constipation was reported by 24 percent of adults on Wegovy in the weight-loss trials, against 11 percent on placebo, and by up to 17 percent on Zepbound, against 5 percent.
Pharmacy options work in two ways. Osmotics, polyethylene glycol (MiraLAX) and magnesium, hold water in the stool so it stays soft. Stimulants, senna and bisacodyl (Dulcolax tablets), make the colon muscle contract. Fiber adds bulk, which helps only with enough water.
Lab note
Hold water first. Push only when you have to.
The 2023 guideline from the American Gastroenterological Association and the American College of Gastroenterology, written for chronic constipation in general rather than for GLP-1 users, gives polyethylene glycol a strong recommendation and fiber, magnesium oxide and senna conditional ones. No laxative has a listed interaction with semaglutide or tirzepatide.
From the labels and drug facts
The numbers to know at the shelf
24% vs 11%
adults with constipation on Wegovy vs placebo, per the Wegovy label
1 to 3 days
for a 17 g dose of MiraLAX to produce a bowel movement, per its Drug Facts label
6 to 12 hours
for senna or bisacodyl to work, which is why they are taken at bedtime, per MedlinePlus
Sources: Wegovy Prescribing Information, June 2026; MiraLAX Drug Facts, DailyMed; MedlinePlus drug information for senna and bisacodyl.
How to choose
- Start with water and soluble fiber. Sip through the day and add a few grams of soluble fiber at a time. Our page on how much fiber to eat on a GLP-1 explains why bran and gummies often backfire.
- Add one osmotic, not two. Either MiraLAX or magnesium citrate, not both on the same day. If you have kidney disease, ask your prescriber before any magnesium.
- Give it the time on the label. MiraLAX usually works in 1 to 3 days at 17 g a day, and its label says to ask a doctor before using it longer than 7 days. Taking more than the label dose is a conversation for your prescriber, not a shortcut.
- Keep a stimulant for rescue. If you are stuck and uncomfortable, senna or bisacodyl at bedtime usually works by the next day. Not more than a week without your doctor; see Dulcolax or senna on a GLP-1 for how to use them.
- On the Wegovy pill or Rybelsus, mind the 30 minutes. Take the tablet with water only and wait at least 30 minutes before food, drinks or other medicines, laxatives and supplements included.
- Build a routine for the days in between. Same dinner time, a walk after it, water through the day. If you want one thing for that routine, see below.
Honest options
If you want to buy one thing
From any pharmacy
- MiraLAX (polyethylene glycol 3350): the osmotic with the strongest guideline backing; 17 g in a drink
- Magnesium citrate: osmotic; a gentle daily dose or a stronger occasional one
- Psyllium (Metamucil): soluble fiber; start small, always with water
- Senna or bisacodyl: rescue only, at bedtime, not for daily use
Pick one osmotic. Check every label’s time limit, and ask before using any of them past it.
What we make
- GLP-1 SOS Daily Gut Relief: 250 mg of magnesium (citrate and oxide) in 2 capsules with dinner, to support regular bowel movements
- A 19-strain probiotic blend with digestive enzymes, plus ginger root and peppermint for digestive comfort
- No fiber and no stimulant laxatives, so it sits next to the fiber you eat and leaves rescue for when you need it
- It counts as your osmotic: skip a separate magnesium supplement unless your doctor says otherwise
60 capsules last 30 days. 60-day money-back guarantee on the first order. Made by GLP-1 SOS, the people behind this Lab.*
*GLP-1 SOS Daily Gut Relief supports regular bowel movements and digestive comfort. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
Two kinds of constipation
Fine to manage, or a same-day call
Fine to manage at home
- Hard stools, a day or two between them
- Some bloating that eases after a bowel movement
- Worse in the days after a shot or a dose increase
- Better within a few days of an osmotic
Call the same day
- Severe or constant belly pain
- Vomiting, or a swollen belly with no gas
- Blood in the stool, or black stool
- Needing a laxative for more than a week
The labels list severe constipation, fecal impaction and bowel obstruction among rare reports.
When to call your doctor
Call your prescriber the same day if:
- You have severe or constant belly pain, with or without vomiting
- Your belly is swollen and you cannot pass gas
- You vomit, or cannot keep liquids down
- You see blood in your stool, or your stool is black
- You have needed a laxative for more than a week
Constipation with pain, vomiting or no gas is not a laxative problem. Call.
From the people behind the Lab
You do not have to figure this out alone.
GLP-1 SOS is the daily companion made for life on a GLP-1. Plain answers like this one, a support team that replies to real questions from real people, and daily formulas like GLP-1 SOS Daily Gut Relief, designed around the side effects that come with the medication. The GLP-1 Lab is our free education arm: no login, no paywall, no hype. Side effects are part of the road. Suffering through them is not.
Questions people also ask
What is the best laxative to take on Ozempic or Wegovy?
For most adults, an osmotic is the best first choice: MiraLAX (polyethylene glycol 3350) or magnesium. Both hold water in the stool without forcing the bowel, and neither has a listed interaction with semaglutide. Pick one, give it one to three days, and add soluble fiber slowly with water. Keep senna or bisacodyl for rescue, and ask before any magnesium if you have kidney disease.
Can I take MiraLAX every day on Zepbound or Mounjaro?
Some prescribers do recommend daily MiraLAX for a stretch, but the Drug Facts label says to ask a doctor before using it for more than 7 days. So the honest answer is: yes, if your prescriber agrees. Tirzepatide has no listed interaction with polyethylene glycol. If you need it every day for weeks, raise it at your next visit.
Is magnesium or MiraLAX better for GLP-1 constipation?
Both are osmotics and work the same way, so the choice is practical. MiraLAX has the stronger guideline recommendation and is not absorbed. Magnesium is a mineral many people already take, comes in capsules, and needs caution with kidney disease. Choose one, not both on the same day. See our pages on magnesium citrate and MiraLAX for details.
Should I take a stool softener or a stimulant for GLP-1 constipation?
Start with neither. An osmotic such as MiraLAX or magnesium is the usual first step because it keeps stool soft without forcing the bowel. Stimulants such as senna or bisacodyl work within 6 to 12 hours and are best kept for an occasional stuck day, for no more than a week without your doctor. If an osmotic is not enough, ask your prescriber what to add.
What can I take for constipation with the Wegovy pill or Rybelsus?
The same options, with one timing rule. Take the tablet with water only, then wait at least 30 minutes before eating, drinking or taking any other medicine, including MiraLAX, magnesium or fiber. After that window, osmotics and fiber work as they do with the shot. Ask your pharmacist to check the timing if you take several medicines.
Sources (7)
- Wegovy (semaglutide) injection and tablets, Prescribing Information. Novo Nordisk / FDA, revised June 2026.
- Zepbound (tirzepatide) injection, Prescribing Information. Eli Lilly, revised August 2026.
- MiraLAX (polyethylene glycol 3350) powder for solution, Drug Facts label. DailyMed, U.S. National Library of Medicine.
- Senna. MedlinePlus Drug Information, National Library of Medicine.
- Bisacodyl. MedlinePlus Drug Information, National Library of Medicine.
- American Gastroenterological Association-American College of Gastroenterology Clinical Practice Guideline: Pharmacological Management of Chronic Idiopathic Constipation. The American Journal of Gastroenterology, 2023.
- Treatment for Constipation. NIH National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).
Reviewed by the GLP-1 SOS editorial team · Education, not medical advice · Talk to your prescriber about your dose and your symptoms.
