How common is constipation on a GLP-1?
Very common, and slower to fade than other stomach side effects. In the semaglutide weight trials pooled on the Wegovy label, constipation affected 24% of people on the 2.4 mg dose versus 11% on placebo. Tirzepatide shows a similar pattern.
A pooled analysis of the STEP trials found constipation reached its plateau around week 10 and that the median episode lasted 47 days, compared with 35 days on placebo. In other words, it tends to settle in rather than come and go, which is why it pays to act early.
Two things drive it. The medicine slows how fast food moves through the gut, and you are simply eating less, so there is less bulk to move.
What should you try first?
Fluids, fiber and movement, in that order. A 2025 joint nutrition advisory on GLP-1 therapy says constipation should be managed proactively, with adequate fluids and fiber from foods, and a gradual increase in fiber-rich foods such as prunes and other dried fruits. The NIDDK suggests that adults get 22 to 34 grams of fiber a day, drink plenty of water when they add fiber, stay physically active and try to have a bowel movement at the same time each day.
Practical steps that fit a small GLP-1 appetite:
- A glass of water with every meal and between meals, more in hot weather or after training
- One fiber food per meal: berries, beans, lentils, oats, vegetables or a few prunes
- Increase fiber gradually rather than all at once
- A daily walk, which helps keep the bowel moving
- A regular bathroom time, such as after breakfast
The advisory also notes that high-protein and high-fat foods can slow stomach emptying further and may need temporary limits when constipation is bad. That needs balancing against your protein target, which your provider can help with.
Which over-the-counter options are reasonable?
When food and fluids are not enough, short-term laxatives are the usual next step. The NIDDK lists these types:
| Type | Examples | Notes |
|---|---|---|
| Fiber supplements | Psyllium (Metamucil), methylcellulose (Citrucel) | Need extra water; start low |
| Osmotic agents | Polyethylene glycol (MiraLAX), milk of magnesia | Draw water into the bowel; the advisory also mentions polyethylene glycol 3350 |
| Stool softeners | Docusate (Colace) | Mild effect |
| Stimulants | Bisacodyl (Dulcolax) | Reserve for severe constipation or when others fail |
Check with your provider before starting any of these, especially if you have kidney disease, since magnesium products may not suit everyone. Extended constipation can also lead to reactive diarrhea, which the advisory flags, so loose stool after days of nothing is a reason to call rather than to stop the fiber.
What are the signs of a bowel blockage?
The Wegovy label lists ileus, intestinal obstruction and severe constipation with fecal impaction among problems reported after the drug reached the market. They are uncommon, but you should know the signs. MedlinePlus lists these symptoms of intestinal obstruction:
- Abdominal swelling or fullness that does not go away
- Cramping belly pain
- Nausea and repeated vomiting
- Being unable to pass gas or stool
Get same-day care, or go to the ER, if you cannot pass stool or gas, your belly is swollen and tender, you keep vomiting, or you have severe abdominal pain that does not ease. Do not take more laxatives to push through those symptoms.
Related question: does constipation mean the dose is too high?
Not necessarily, but it is worth reporting. Constipation often appears early and lingers even on a stable dose. If it keeps returning despite good habits, your provider may slow the next dose step. For the full list of side effects and their timing, see common side effects of semaglutide; for the other big one, see stopping nausea on semaglutide.
How Ultimate Male handles constipation on treatment
At Ultimate Male, bowel habits are part of every check-in on the medical weight loss program, because they are easy to fix early and miserable to fix late. Your PA-C or MD reviews fluids, fiber, protein and medicines that can add to constipation, then suggests a plan that fits your appetite.
If you are using tirzepatide or semaglutide and things have stalled for more than a few days, call 626-319-5261. Our GLP-1 warning signs guide also sorts symptoms into routine, call-today and emergency groups.
