Guides / Side effects and results

GLP-1 constipation: how common it is, and when to get help

Constipation is one of the most common GLP-1 side effects, and it tends to hang around longer than nausea does.

By PeptideTracker editorial team · Updated November 8, 2026 · 7 sources

[00] Short answer

  1. Constipation was reported by 24% of adults on Wegovy 2.4 mg vs 11% on placebo1.
  2. On Zepbound it was 11–17% vs 5% on placebo, and on Foundayo 20–27% vs 9%2–3.
  3. In the semaglutide 2.4 mg trials, a bout of constipation lasted a median of 47 days, vs 35 days on placebo6.
  4. Ileus, bowel blockage and severe constipation with fecal impaction have been reported after these medicines went on sale1–3,5.
  5. The labels tell people to contact their provider about stomach symptoms that are severe or won't go away1–2.

How common is constipation on GLP-1 medicines?

In the weight-loss trials, constipation was reported by 24% of adults on Wegovy 2.4 mg, 11% to 17% on Zepbound and 20% to 27% on Foundayo. On placebo it was 11%, 5% and 9% in those trials1–3.

Percent of adults with constipation: weight-management trials (US labels, section 6.1)
Medicine and doseOn the medicineOn placeboTrial length, source
Wegovy 2.4 mg weekly124%11%68 weeks, Table 3
Wegovy 7.2 mg weekly120%8% (19% on 2.4 mg)72 weeks, Table 4
Zepbound 5 mg217%5%72 weeks, Table 1
Zepbound 10 mg214%5%72 weeks, Table 1
Zepbound 15 mg211%5%72 weeks, Table 1
Foundayo 5.5 mg daily320%9%72 weeks, Table 1
Foundayo 9 mg daily327%9%72 weeks, Table 1
Foundayo 17.2 mg daily324%9%72 weeks, Table 1

The Wegovy 7.2 mg trials compared 7.2 mg, 2.4 mg and placebo in the same people, so both comparison rates are shown1.

In the type 2 diabetes trials of Ozempic and Mounjaro, the rates were lower, but so was the placebo rate, and the people and doses were different.

Percent of adults with type 2 diabetes reporting constipation (US labels, Table 1)
Medicine and doseOn the medicineOn placeboSource
Ozempic 0.5 mg45%1.5%Table 1
Ozempic 1 mg43.1%1.5%Table 1
Mounjaro 5 mg56%1%Table 1
Mounjaro 10 mg56%1%Table 1
Mounjaro 15 mg57%1%Table 1

In the Mounjaro heart outcomes trial of 6,647 adults with type 2 diabetes and heart disease, 13% on Mounjaro reported constipation5. The labels say rates from one drug's trials can't be directly compared with another's1–2.

UK note: the UK Mounjaro SmPC lists constipation as "very common" (more than 1 in 10 people) in the weight-management trials, and "common" in the diabetes trials7.

Is GLP-1 constipation worse on a higher dose?

Not always. On Zepbound, constipation was most common at the lowest maintenance dose: 17% on 5 mg, 14% on 10 mg and 11% on 15 mg2. On Foundayo it peaked at 9 mg (27%), and on Ozempic it was 5% on 0.5 mg and 3.1% on 1 mg3–4.

Wegovy 7.2 mg and 2.4 mg were close in the same trials, at 20% and 19%1. The labels give these numbers without explaining the pattern, so the reason isn't known.

How long does constipation last on a GLP-1?

Longer than other stomach side effects. In the pooled STEP 1–3 trials of semaglutide 2.4 mg, a bout of constipation lasted a median of 47 days, compared with 8 days for nausea. On placebo, constipation lasted a median of 35 days6.

  • When it settles: the share of people with constipation leveled off at about week 10 of those trials6.
  • Why it may last: the authors suggested it may be because GLP-1 medicines affect how the gut moves, and said the evidence is lacking6.
  • Later on: in STEP 4, among people who kept taking semaglutide after a 20-week start, constipation became less common over time6.

The labels for semaglutide, tirzepatide and orforglipron all say these medicines slow stomach emptying1–3. Timings for nausea and vomiting are in the GLP-1 side effects guide.

When should you get help for constipation on a GLP-1?

Contact your provider if stomach symptoms are severe or won't go away. That's the instruction the Wegovy and Zepbound labels give1–2. Severe stomach side effects were reported in 4.1% on Wegovy 2.4 mg vs 0.9% on placebo, and in 1.7% to 3.1% on Zepbound vs 1%1–2.

  • Ileus and blockage: ileus (when the gut stops moving its contents along), intestinal obstruction and severe constipation with fecal impaction are listed in the postmarketing sections of the Wegovy, Zepbound and Mounjaro labels1–2,5. Foundayo lists the same reports for GLP-1 medicines as a group3. Postmarketing reports are voluntary, so the labels say their frequency can't be reliably estimated.
  • Severe stomach pain that won't go away, with or without vomiting, sometimes reaching your back: the Wegovy Medication Guide says to stop the medicine and call your provider right away, because it can be a sign of pancreatitis1.
  • Severe gastroparesis: Wegovy, Zepbound and Foundayo are not recommended for people who already have severe gastroparesis (a stomach that empties very slowly)1–3.
  • Before surgery or sedation: tell the team you take a GLP-1, because of the risk of food getting into the lungs1–2.

Questions

How common is constipation on Wegovy?

In the Wegovy 2.4 mg weight-loss trials, 24% of adults reported constipation, compared with 11% on placebo. In the 7.2 mg trials, it was 20% on 7.2 mg, 19% on 2.4 mg and 8% on placebo.

Does Zepbound or Mounjaro cause constipation?

Yes. On Zepbound it was 17% at 5 mg, 14% at 10 mg and 11% at 15 mg, vs 5% on placebo. In the Mounjaro type 2 diabetes trials it was 6% to 7% vs 1% on placebo.

How long does GLP-1 constipation last?

In the pooled STEP 1–3 trials of semaglutide 2.4 mg, the median bout lasted 47 days, compared with 35 days on placebo. That's much longer than nausea, which lasted a median of 8 days.

Can a GLP-1 cause a bowel blockage?

Ileus, intestinal obstruction and severe constipation with fecal impaction have been reported since these medicines went on sale. These are voluntary reports, so the labels say how often they happen can't be reliably estimated.

Does constipation get worse at higher doses?

Not on every label. Zepbound had the most constipation at 5 mg (17%) and the least at 15 mg (11%). Foundayo peaked at 9 mg (27%).

Is constipation on Foundayo more common than on injections?

Foundayo's rate was 20% to 27% vs 9% on placebo, but the labels say rates from different drugs' trials can't be directly compared, because the trials enrolled different people.

Sources

Checked against Wegovy, Zepbound, Foundayo, Ozempic and Mounjaro US prescribing information (2026), the UK Mounjaro SmPC (August 2026), and the pooled STEP 1–3 tolerability analysis (Diabetes Obes Metab 2022). How we check

  1. 1Wegovy (semaglutide) injection and tablets, US prescribing information and Medication Guide, sections 5.6, 6.1, 6.2, 12.2 and 17. Novo Nordisk, revised 06/2026; Tables 3 and 4
  2. 2Zepbound (tirzepatide) US prescribing information, sections 5.2, 6.1, 6.2, 12.2 and 17. Eli Lilly, revised 08/2026; Table 1
  3. 3Foundayo (orforglipron) tablets, US prescribing information, sections 5.3, 6.1, 6.2 and 12.2. Eli Lilly, revised 07/2026; Table 1
  4. 4Ozempic (semaglutide) injection, US prescribing information, section 6.1. Novo Nordisk, revised 05/2026; Table 1
  5. 5Mounjaro (tirzepatide) US prescribing information, sections 6.1 and 6.2. Eli Lilly, revised 08/2026; Table 1
  6. 6Wharton S, et al. Gastrointestinal tolerability of once-weekly semaglutide 2.4 mg in adults with overweight or obesity. Diabetes Obes Metab 2022;24:94-105. doi:10.1111/dom.14551; section 3.3 and discussion
  7. 7Mounjaro KwikPen, UK Summary of Product Characteristics, section 4.8. Eli Lilly, revised 29 August 2026; accessed 8 Nov 2026

This guide explains what labels and published studies say. It isn't medical advice and doesn't replace your prescriber or pharmacist.

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