What Is Ozempic? How Semaglutide Works, What It Treats and What It Isn't

Ozempic is the brand name for semaglutide, a prescription glucagon-like peptide-1 (GLP-1) receptor agonist made by Novo Nordisk and injected under the skin once a week.1 Its FDA-approved uses are all in adults with type 2 diabetes: improving blood sugar control alongside diet and exercise, reducing the risk of major cardiovascular events in those with established cardiovascular disease, and reducing the risk of kidney decline, kidney failure and cardiovascular death in those with chronic kidney disease.1

The injection comes in two forms. Multi-dose, single-patient-use pens deliver 0.25 mg, 0.5 mg, 1 mg or 2 mg per weekly dose, and single-dose prefilled syringes hold 0.25 mg, 0.5 mg or 1 mg.1 Treatment starts at 0.25 mg once weekly for 4 weeks, then steps up to 0.5 mg; the dose can rise to 1 mg and then to a 2 mg maximum, each after at least 4 weeks on the previous dose, if more glucose control is needed.1

Since early 2026 the Ozempic name also covers a tablet. The FDA approved renaming the R2 formulation of Rybelsus, an oral semaglutide, as Ozempic (semaglutide) tablets.6 This article is about the weekly injection unless it says otherwise. For what each form costs, see Ozempic cost.

Ozempic lowers blood sugar by making the pancreas release more insulin and less glucagon, but only when blood glucose is high.1 The label calls this a glucose-dependent effect: when glucose is elevated, insulin secretion is stimulated and glucagon secretion is held back.1 A smaller part of the effect comes from slightly slowing how fast the stomach empties after a meal, which slows how quickly glucose from food reaches the blood.1

Two design features make once-weekly dosing possible. Semaglutide binds tightly to albumin in the blood (more than 99%), which slows its clearance by the kidneys and protects it from breakdown, and it is modified to resist DPP-4, the enzyme that breaks down the body's own GLP-1.1 The result is an elimination half-life of about one week; semaglutide stays in circulation for about 5 weeks after the last dose.1 Steady levels are reached after 4 to 5 weeks of weekly injections.1

Semaglutide also reduces body weight, which is why it is studied and sold, under another brand, for weight management.1 The brain has GLP-1 receptors in areas that regulate appetite, and the Wegovy label attributes semaglutide's weight effect to lower calorie intake, likely through appetite.2

No. Ozempic is not insulin. It is a GLP-1 receptor agonist, a different class of medicine that prompts the body to release its own insulin when blood sugar is high.1

The distinction matters in practice. The label's warning about low blood sugar centers on combinations: the risk increases when Ozempic is used with insulin or with an insulin secretagogue such as a sulfonylurea, and the label says the dose of those drugs may need to be reduced.1 When Ozempic and insulin are used together, they are given as separate injections and never mixed.1

Yes. Semaglutide is a peptide: a chain of amino acids built to resemble the human hormone GLP-1, with 94% sequence homology to it.1 Its peptide backbone is produced by yeast fermentation, then modified with a fatty-acid side chain that lets it bind albumin and last a week.1 Its molecular formula is C187H291N45O59, with a molecular weight of 4113.58 g/mol.1

That is the same reason Ozempic is injected rather than swallowed in its pen form: peptides are broken down in the gut. The oral versions come with strict conditions: the Wegovy tablet is taken on an empty stomach with no more than 4 ounces of water, followed by a wait of at least 30 minutes before eating, drinking or taking other oral medicines.2

"Peptide" is also a marketing word online. The FDA warns that semaglutide sold as "research use only" or "not for human consumption" is of unknown quality and may be harmful, and that semaglutide salt forms (sodium and acetate) are different active ingredients from the ones in approved drugs.9

No. Ozempic is not FDA approved for weight loss. All three of its labeled uses are in adults with type 2 diabetes.1 The semaglutide product that is FDA approved for weight management is Wegovy.2

Wegovy is indicated, together with a reduced-calorie diet and more physical activity, to reduce excess body weight and keep it off long term in adults and children aged 12 and older with obesity, and in adults with overweight who have at least one weight-related condition.2 It is also approved to reduce the risk of heart attack, stroke and cardiovascular death in adults with established cardiovascular disease and obesity or overweight, and to treat a form of fatty liver disease (noncirrhotic MASH with moderate to advanced fibrosis) under accelerated approval.2

The weight-loss evidence for semaglutide comes from Wegovy's trials. In STEP 1, adults without diabetes taking semaglutide 2.4 mg weekly lost a mean 14.9% of body weight over 68 weeks, compared with 2.4% on placebo.7 A doctor can still prescribe Ozempic for a use outside its label; how to get Ozempic covers what that involves.

Semaglutide is the active ingredient; Ozempic is one brand of it. Every Ozempic pen, syringe and tablet contains semaglutide, but not every semaglutide product is Ozempic.1,6

The FDA-approved semaglutide brands are Ozempic and Wegovy, both from Novo Nordisk, plus the remaining Rybelsus tablet formulation.6 Compounded semaglutide, mixed by pharmacies, is a separate category: the FDA states that compounded drugs are not FDA approved and are not reviewed for safety, effectiveness or quality before they are sold.9 See compounded semaglutide vs Ozempic for how the two compare.

Wegovy and Ozempic contain the same drug, semaglutide, but they are different products with different approved uses, doses and devices.1,2

The Wegovy label says it should not be used together with other semaglutide-containing products or any other GLP-1 receptor agonist.2 A side-by-side breakdown is in Ozempic vs Wegovy, and our dose converter maps doses between them.

The FDA approved Ozempic on December 5, 2017, so as of October 2026 it has been on the U.S. market for nearly nine years.3 The original approval was for improving blood sugar control in adults with type 2 diabetes; the cardiovascular and kidney indications were added later.3,1

Wegovy followed in June 2021 as the first drug approved for chronic weight management in adults with general obesity or overweight since 2014.4 The Wegovy pill, a once-daily 25 mg oral semaglutide, was approved on December 22, 2025, as the first oral GLP-1 for weight management.5

"Ozempic face" is a popular, not medical, term for the gaunt look, sunken cheeks, new wrinkles and loose skin that can follow rapid weight loss.8 Cleveland Clinic attributes it to the loss of fat under the facial skin, not to the medication itself, and notes that similar changes follow bariatric surgery or other fast weight loss.8 Ways to limit it are covered in Ozempic side effects.

Ozempic is injected once a week, on the same day each week, at any time of day, with or without food, into the abdomen, thigh or upper arm.1 The step-by-step pen technique is in how to inject Ozempic, and the label's rule for a missed dose is built into our missed-dose tool.

It is not for everyone. Ozempic carries a boxed warning about thyroid C-cell tumors seen in rodents, and it must not be used by anyone with a personal or family history of medullary thyroid carcinoma or with multiple endocrine neoplasia syndrome type 2 (MEN 2).1 The full list of warnings is summarised on our safety page.

What is Ozempic used for? Improving blood sugar control in adults with type 2 diabetes, and lowering the risk of major cardiovascular events and of kidney decline in adults with type 2 diabetes who have heart disease or chronic kidney disease.1

Is Ozempic a GLP-1? Yes. Semaglutide is a GLP-1 receptor agonist: it binds to and activates the same receptor as the body's own GLP-1 hormone.1

Can people with type 1 diabetes use Ozempic? Ozempic's approved uses are limited to adults with type 2 diabetes.1 Any other use is a decision for a prescriber.

Is Ozempic the same as Mounjaro? No. Mounjaro is tirzepatide, a different molecule from a different maker. See Mounjaro vs Ozempic and tirzepatide vs semaglutide.

Does Ozempic need a prescription? Yes. The label describes Ozempic as a prescription medicine, and the FDA advises getting a prescription and filling it at a state-licensed pharmacy.1,9

If you are weighing semaglutide, compare the approved brands and the programs that prescribe them on our best GLP-1 providers page, or go straight to semaglutide online for the options that ship nationally.

This article is for information only and is not medical advice. Ozempic and Wegovy are prescription drugs with real risks and side effects — talk to a licensed clinician before starting, changing or stopping any treatment.