Ozempic (Semaglutide)

Ozempic (semaglutide) is a prescription medicine for treating Type 2 diabetes in adults. It’s also used to reduce cardiovascular and kidney risks in patients with Type 2 diabetes and heart or kidney conditions. It belongs to the GLP-1 receptor agonist class of drugs, which includes Mounjaro, Rybelsus and Wegovy. These medications work by mimicking a natural hormone that regulates blood sugar and appetite.

The FDA approved Ozempic for diabetes in December 2017. Although not FDA-approved for weight loss, it is sometimes prescribed off-label for this purpose. Patients self-administer weekly injections in the thigh, abdomen or upper arm. Standard dosing begins at 0.25 mg weekly, increasing to 0.5 mg after four weeks.

Another semaglutide injection, Wegovy, is FDA-approved for this purpose. In 2025, a pill version of Wegovy was also approved for weight loss. The term “off-label use” refers to prescribing a medication to treat a condition for which the drug is not FDA-approved.

Side Effects of Ozempic

The most common Ozempic side effects are minor and affect the digestive system.

Serious Ozempic side effects are rare, but they can happen. These include pancreatitis, vision problems like NAION or worsening diabetic retinopathy, low blood sugar when taken with insulin or sulfonylureas, acute kidney injury, severe digestive issues such as gastroparesis or ileus, allergic reactions, gallbladder disease and a higher risk of aspiration during surgery because Ozempic slows digestion.

What Should You Do if You Experience Ozempic Side Effects

For mild effects like nausea or vomiting, discuss symptoms at your next doctor visit, though persistent symptoms may lead to dehydration and kidney damage.

For severe symptoms — persistent stomach pain, vision changes, neck swelling, breathing difficulty, low blood sugar symptoms, uncontrolled vomiting or diarrhea, allergic reactions or upper abdominal pain with fever — seek immediate help.

If you develop gastroparesis, intestinal blockages or vision problems, consult an attorney, as these injuries form the basis of current lawsuits.

GLP-1 drugs, including Ozempic, have been linked to gastroparesis (stomach paralysis) and intestinal blockages (ileus). An October 2023 JAMA research letter found gastroparesis risk three to four times higher and pancreatitis risk about nine times higher among GLP-1 users compared to people on Contrave (bupropion-naltrexone).

“These medications slow how fast food empties the stomach,” Dr. Lauren Cunningham, a clinical pharmacist and pharmacy professor at the University of Illinois Chicago, told Drugwatch. “So, avoiding an active gastroparesis is important to prevent issues like bowel obstructions.”

In 2023, the FDA updated Ozempic’s label to warn of ileus risk after receiving 33 blockage reports from semaglutide users, along with two deaths.

Ozempic Lawsuits Claim Gastrointestinal Injuries

Patients who developed gastroparesis, ileus, intestinal obstruction or other gastrointestinal injuries after taking Ozempic or other GLP-1 drugs have filed lawsuits against the manufacturers. As of May 2026, 3,636 cases are pending in MDL 3094 in the Eastern District of Pennsylvania. These cases cover Ozempic, Wegovy, Rybelsus, Mounjaro and Trulicity.

Ozempic lawsuits claim the manufacturers did not adequately warn users about the risks of GI injuries. So far, there have been no trials, verdicts or settlements.

Multiple studies since 2024 suggest an association between semaglutide and an increased risk of NAION (non-arteritic anterior ischemic optic neuropathy). NAION involves sudden, painless vision loss in one eye, typically upon waking, due to disruption of blood flow to the optic nerve. Vision loss is typically permanent, though it is often stable after onset.

A 2024 JAMA Ophthalmology study of over 16,000 patients showed people with Type 2 diabetes or obesity taking semaglutide had significantly higher NAION risk than those on other medications.

A 2024 Danish study of more than 424,000 people with Type 2 diabetes found that once-weekly semaglutide users had twice the NAION risk of non-users, with the elevated risk holding even after researchers accounted for other risk factors.

A 2025 international study of over 37 million Type 2 diabetes patients found a slightly increased NAION risk among semaglutide users, lower than earlier studies but still present. Research published in JAMA Ophthalmology stated that more studies are needed to understand the ocular effects of semaglutide and identify the highest-risk patients.

European Union Recommended NAION Warnings

In June 2025, the European Medicines Agency (EMA) recommended updating the labeling for semaglutide to list NAION as a very rare side effect, affecting up to 1 in 10,000 users. The organization recommended label changes to classify NAION as a “very rare” side effect for EU-marketed drugs.

The EMA said people who develop sudden vision loss or rapidly worsening eyesight should seek medical care right away, and treatment should be stopped if NAION is confirmed.

Lawsuits Claim Ozempic, Wegovy Caused NAION

Individuals who developed NAION after taking Ozempic or Wegovy have filed lawsuits alleging Novo Nordisk failed to warn of vision-loss risks. Many of these lawsuits have been consolidated into MDL 3163 in an Eastern Pennsylvania federal court.

Other NAION lawsuits have been combined into a multicounty litigation (MCL) in New Jersey state court.

“There are obviously other risks that are warned about with taking Ozempic or Wegovy, but a lot of those risks are temporary in nature.” Danielle Gold, an attorney with Weitz & Luxenberg, told Drugwatch. “Whereas if you develop NAION while on this medication, it will likely result in permanent visual impairment.”

Since Ozempic’s approval, the FDA has repeatedly highlighted potential risks, including thyroid tumors, pancreatic inflammation, digestive issues and drug interactions. Recent concerns focus on counterfeit or adulterated versions, emphasizing purchasing only from licensed pharmacies.

Ozempic Black Box Warning

The original Ozempic label included a black box warning against use by individuals with personal or family histories of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia syndrome type 2 (MEN 2).

It listed common side effects, including stomach pain and constipation, noting that slowed digestion may impact the effectiveness of other oral medications. The label warned pregnant individuals to stop Ozempic at least two months before conception.

These warnings remained consistent across FDA label updates, with continued emphasis on thyroid tumors, pancreatitis and gastrointestinal risks. The FDA continued to recommend reporting suspected adverse reactions through the MedWatch program.

FDA Warns of Unapproved Versions of GLP-1 Drugs

As GLP-1 popularity increased for weight loss, manufacturers faced supply shortages beginning in 2022. Compounding pharmacies filled this gap by producing customized GLP-1 medications. While the FDA recognizes compounded medications as necessary for some patients, these products lack FDA approval.

The FDA removed Ozempic from the shortage list in February 2025.

In May 2025, the FDA warned the public about unapproved or compounded semaglutide risks, noting the agency has not reviewed these products for safety, quality or effectiveness. Some compounded versions caused serious side effects, including nausea, vomiting and hospitalizations from dosing errors.

The FDA also found that some compounded versions use unapproved semaglutide salt forms (semaglutide sodium and semaglutide acetate), which may not function as expected due to different active ingredients. The FDA recommends using only FDA-approved semaglutide from licensed pharmacies with medical consultation regarding proper dosing.

Ozempic is one of several GLP-1 receptor agonist drugs FDA-approved for Type 2 diabetes or weight management, including Wegovy, Mounjaro, Saxenda, Rybelsus and Zepbound.

Ozempic, Wegovy and Rybelsus all use semaglutide as their main ingredient, but they have different doses and approved uses. Mounjaro and Zepbound contain tirzepatide, which acts on both glucagon-like peptide-1 (GLP-1) and Gastric inhibitory polypeptide (GIP) and may lead to greater weight loss in some studies.

Most of these drugs are given as weekly injections, but some, like Rybelsus, are taken by mouth every day. Saxenda is a daily injection.