Ozempic and Gastroparesis: How Real Is “Stomach Paralysis”?

Ozempic, Wegovy, Mounjaro and Zepbound do slow the stomach, and people taking them are diagnosed with gastroparesis more often than people on other treatments. The excess is real and small: in the largest cohort of people using semaglutide for weight, about 6.5 diagnoses per 1,000 people a year, against 2.1 on another weight-loss drug.^[7] “Paralysis” overstates it. The slowing is measured in tens of minutes, it fades with time on some drugs, and every published case report of drug-linked gastroparesis describes symptoms resolving once the drug was stopped.^[11][17] The Ozempic label carried no gastroparesis warning until 2025. More than 4,000 lawsuits are pending in one federal court, and in August 2025 the judge ruled that a gastroparesis claim needs a proper stomach-emptying test behind it.^[20][24]

Slowed is not paralyzed

Gastroparesis is a diagnosis, not a feeling. It means the stomach empties too slowly with nothing physically blocking it, confirmed on a test, alongside symptoms such as nausea, vomiting, early fullness and bloating. “Stomach paralysis” is a headline word. Nobody on these drugs has a stomach that stops; the question is how much slower it gets and for how long.

Every one of the four labels says the drug delays gastric emptying.^[1][4] That is part of how they work: food leaves the stomach later, sugar reaches the blood later, and people feel full sooner. The same property is why each label warns that oral pills taken alongside may be absorbed differently, which matters most for birth control pills on Mounjaro and Zepbound, and why anesthetists now ask about these drugs before sedation, covered in GLP-1 drugs before an endoscopy or surgery.

What the labels say now, and when they started saying it

All four current labels carry a warning headed “Severe Gastrointestinal Adverse Reactions”, each ending in the same instruction about gastroparesis.

Severe gastrointestinal adverse reactions have also been reported postmarketing with GLP-1 receptor agonists. OZEMPIC is not recommended in patients with severe gastroparesis.

— Ozempic prescribing information, section 5.7

The warning is newer than most coverage suggests. Ozempic’s archived labels on DailyMed show the sequence.^[2]

The postmarketing list now names ileus, intestinal obstruction and severe constipation with fecal impaction on Ozempic, Wegovy, Mounjaro and Zepbound alike.^[1][4] It names gastroparesis on none of them. Those lists come from voluntary reports, and the labels say outright that such reports cannot give a frequency or prove the drug caused the event.^[1]

The trial figures in that same warning are the closest thing to an official rate, and they count all severe stomach reactions, not gastroparesis alone.

How often gastroparesis is diagnosed: the cohort numbers

No trial was large or long enough to count gastroparesis, and a pooling of 55 placebo-controlled trials with 106,395 people found the drugs probably have little or no effect on it or on most other serious gut events, apart from gallstones and reflux.^[10] The signal comes from insurance and health-record cohorts, which see far more people but rely on diagnosis codes rather than tests.

The 2023 JAMA research letter is the study most often quoted, and its semaglutide arm rested on four diagnoses. It counted a gastroparesis code or a prescription for a drug that speeds the stomach as a case, so someone given a motility drug for nausea would count.^[6] The 2025 cohort is the better estimate for weight-loss users: tens of thousands of people, the same direction, and roughly three times the rate of the comparison drug.^[7] Some of its authors were employed by a maker of surgical robots, which they disclosed; sleeve gastrectomy was one of its comparators.^[7] The 2026 diabetes cohort found the excess held for each component of its composite and across every drug and subgroup it checked; the difference worked out to 0.27 extra events per 100 people per year.^[8]

Mounjaro and Zepbound

Tirzepatide carries the same warning and the same postmarketing list.^[4][5] No cohort in this review reports a gastroparesis rate for Mounjaro or Zepbound on their own. Head to head, a 2026 study of adults with type 2 diabetes found no meaningful difference in serious stomach and bowel events, gastroparesis included in the composite, between tirzepatide and semaglutide (hazard ratio 1.07, 0.90 to 1.26) or between either one and dulaglutide.^[9] On present evidence the risk looks like a class effect rather than a property of one brand.

How much the stomach actually slows, and whether it adapts

The reference test is gastric emptying scintigraphy: a meal tagged with a small radioactive marker, scanned for four hours. Pooling the five scintigraphy studies of these drugs, 247 people in all, the time for half a meal to leave the stomach was about 36 minutes longer on a GLP‑1 than on placebo (138 against 95 minutes).^[11] In one 12-week trial of semaglutide 1 mg in 20 women, 37% of a solid meal was still in the stomach at four hours, against none in the placebo group.^[12] So the slowing can be large in some people.

It also tends to wear off, at least partly. Physiologists call this tachyphylaxis: the body’s response shrinks as exposure continues.

• Native GLP‑1. In nine healthy volunteers given a GLP‑1 infusion, emptying slowed more after the first meal than after a second meal four hours later.^[13]
• Liraglutide. In a 16-week trial of the Saxenda dose, the median delay against baseline was 70 minutes at week 5 and 30.5 minutes at week 16, still longer than on placebo.^[14]
• Tirzepatide. The Mounjaro and Zepbound labels say the effect on emptying was greatest after the first 5 mg dose and diminished with later doses.^[4] Lilly’s own study found the same in healthy people, with some delay remaining in people with diabetes who stepped up the dose.^[15]
• Semaglutide 2.4 mg. A Novo Nordisk trial found no evidence of delayed emptying at week 20, but it used an indirect test that tracks liquids better than solids.^[16] The Ozempic label notes the same null result.^[1]

The evidence does not all point one way. The 12-week semaglutide scan above found a marked delay, and the pooled analysis found that time on treatment did not change the size of the delay across studies.^[11][12] The fair reading: the effect is strongest early and at each dose step, it weakens in many people, and it does not vanish for everyone.

Does it go away after stopping?

In every published case report, yes. A 2026 systematic review found 12 reports describing 13 people with gastroparesis linked to a GLP‑1, most often semaglutide, frequently after a fast dose increase or restarting at a high dose. Symptoms resolved in all of them after the drug was stopped.^[17]

That is weak evidence in both directions. Thirteen people is not a rate, and case reports favor clear stories with tidy endings. No cohort has followed people diagnosed on these drugs to see how many still have slow emptying a year after stopping. The cohorts above could not tell lasting diagnoses from temporary ones.^[7] Until that study exists, nobody can say how often the problem persists. The question is exactly what is in dispute in the litigation: the court has recorded that most plaintiffs say their gastroparesis is persistent rather than temporary.^[23]

How long ordinary side effects last on these drugs is a separate, better-studied question, covered in how long GLP-1 side effects last. Constipation, which outlasts nausea and is sometimes mistaken for a stomach problem, has its own page: GLP-1 constipation: what works.

The lawsuits: where MDL 3094 stands

Federal claims that GLP‑1 drugs caused stomach and bowel injuries are combined in one proceeding: In re: Glucagon-Like Peptide-1 Receptor Agonists (GLP-1 RAs) Products Liability Litigation, MDL No. 3094, in the Eastern District of Pennsylvania before Judge Karen S. Marston. The facts below come only from the court’s and the Judicial Panel’s own records. The drugmakers deny the allegations.^[21]

Sources for the table: the 2024 transfer orders,^[18][19] the court’s case management orders,^[22][25] the August 2025 memorandum and order,^[23][24] the panel’s October 2026 caseload report,^[20] and the October 2026 scheduling order.^[26] By the court’s August 2025 memorandum, eight drugs were at issue, including Victoza and Zepbound.^[23] As of October 17, 2026, the court’s posted orders show no decision yet on issues 2 and 3, and no trial date.

Any Plaintiff claiming to suffer (or have suffered) from gastroparesis, must show that their diagnosis is based on a properly performed gastric emptying study (scintigraphy, breath test, or WMC).

— Order, MDL No. 3094, E.D. Pa., August 15, 2025

WMC is a wireless motility capsule, which the court listed with the breath test as accepted alternatives to scintigraphy.^[23] The memorandum adds that the test must have been done at the time of diagnosis and must have confirmed delayed emptying, and the judge acknowledged that some plaintiffs will be unable to prove gastroparesis because no such test was done.^[23] Whatever happens to the lawsuits, the ruling makes a clinical point that applies to anyone: a gastroparesis label without an emptying study is a working guess.

If you think you have it

1. Separate the pattern. Nausea and fullness that flare for a few days after each dose step and then settle is the drug doing what its label describes. Vomiting that goes on for days, food from hours or a day earlier coming back up, or weight falling because nothing stays down is a different pattern and needs a call to the prescriber.
2. Ask whether a test was done. If someone tells you that you have gastroparesis, ask whether it was confirmed by a gastric emptying study. The diagnosis carries more weight, medically and otherwise, if it was.
3. Dose changes come first. Wegovy’s label tells prescribers to consider holding the next dose increase for four weeks when a step is not tolerated, and the case reports cluster around fast escalation.^[3][17] Stopping or changing the dose is the prescriber’s call, not one to make alone.
4. Know the emergencies. Severe belly pain that will not settle, pain through to the back, a swollen belly with no stool or gas, or being unable to keep fluids down for a day are not wait-and-see symptoms. The full list is in GLP-1 stomach pain: when to worry.