Semaglutide: uses, dosing, side effects & brands

Ozempic (Semaglutide) is a GLP-1 receptor agonist used to treat Type 2 Diabetes Mellitus.

The FDA classifies semaglutide as a glp-1 receptor agonist. GLP-1 receptor agonists mimic the gut hormone GLP-1: they prompt the pancreas to release insulin when blood sugar is high, curb the release of glucagon, and slow stomach emptying, which lowers blood sugar and reduces appetite. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.

The elimination half-life of semaglutide is about 1 week (roughly 7 days) — that is how long the body takes to clear half of a dose. This is the elimination half-life of semaglutide itself (the injectable, Ozempic/Wegovy); because it is so long, the drug stays in the body for about 5 weeks after the last dose. No active metabolite with a longer half-life is described. Half-life is not the same as how long a drug test can detect the drug, and it varies with age, kidney and liver function.

It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run semaglutide against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.

We track 4 semaglutide-containing products in the U.S.: Ozempic, Rybelsus, Wegovy and Wegovy Hd. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.

Across the brands we track, semaglutide is currently marketed as injectable and tablet, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.

We do not currently list a generic-labelled semaglutide product. That does not always mean none exists — it means none appears under a generic name in the FDA data we track. Ask your pharmacist.

The FDA's Enforcement database lists at least 5 recall records whose product description mentions semaglutide. The most recent: SEMAGLUTIDE 7.5mg (5mg/mL) (Jul 29, 2026). A recall applies to specific lots, not to the drug as a whole — check the record for the affected lot numbers.

The most common side effects are gastrointestinal: nausea, vomiting, diarrhea, constipation, and stomach (abdominal) pain. In Ozempic's diabetes-dose (0.5-1 mg) trials, nausea affected roughly 16-20% of people, diarrhea about 9%, vomiting 5-9%, abdominal pain about 7%, and constipation about 5%. At Wegovy's higher weight-loss dose (2.4 mg) these are markedly more common — nausea in roughly 44% in the STEP trials — so expect more GI upset on Wegovy than these Ozempic figures show. MedlinePlus also lists heartburn, burping, headache, and cold-like symptoms. These effects are dose-related: they are usually worst right after a dose increase and tend to ease over days to weeks as your body adjusts, which is exactly why prescribers start low and step the dose up slowly. Tell your doctor if nausea or vomiting is severe or keeps you from drinking fluids.

Get medical help right away for these. Pancreatitis: MedlinePlus describes "ongoing pain that begins in the upper left or middle of the stomach but may spread to the back, with or without vomiting." Gallbladder disease: "pain in upper stomach; yellowing of skin or eyes; fever; or clay-colored stools." Kidney injury from dehydration: "decreased urination; or swelling of legs, ankles, or feet." Severe stomach or intestinal problems (which can include a rare bowel blockage/ileus) and vision changes are also listed as reasons to call your doctor. Call 911 for a serious allergic reaction: "rash; itching; fainting or dizziness; swelling of the eyes, face, mouth, tongue, or throat; or difficulty breathing or swallowing." This is not a complete list — check the FDA label and your pharmacist's leaflet.

Yes. Semaglutide carries the FDA's most serious "boxed" warning. Per the label: "In rodents, semaglutide causes thyroid C-cell tumors... It is unknown whether OZEMPIC causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans." Because of this, Ozempic and Wegovy are contraindicated (should not be used) in anyone with a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2). MedlinePlus says to tell your doctor immediately if you notice "a lump or swelling in the neck; hoarseness; difficulty swallowing; or shortness of breath." Discuss your family history with your prescriber before starting.

This is an emerging but rare signal. Semaglutide has been linked to NAION (non-arteritic anterior ischemic optic neuropathy), a sudden, usually painless loss of vision in one eye caused by reduced blood flow to the optic nerve. Regulators have moved to add NAION as a rare labeled side effect after safety reviews. NAION can cause permanent, irreversible vision loss, and there is no proven treatment to reverse it. Sudden vision changes are already listed in the drug information as a reason to call your doctor promptly. If you notice sudden blurring or loss of vision in one eye, seek care right away. Also note the label warns semaglutide can worsen diabetic retinopathy in people with diabetes.

Stomach-related side effects typically start within the first days after your first dose or after each dose increase, and for most people they ease over the following weeks as the body adapts. They often flare again at the next higher dose, which is why the schedule steps up gradually. Serious problems like pancreatitis, gallbladder disease, or NAION can appear at any point in treatment, not just at the start. Do not stop semaglutide on your own if it was prescribed for you — dosing and any decision to pause or stop is managed by your prescriber, who may adjust your dose to control side effects. If you are also taking insulin or a sulfonylurea, semaglutide raises the risk of low blood sugar (hypoglycemia), and your doctor may need to lower those medications; watch for shakiness, sweating, confusion, or dizziness.