Semaglutide (Ozempic, Wegovy)

A once-weekly GLP-1 shot approved for type 2 diabetes, weight management and lowering heart risk. The daily pill (Wegovy pill, Rybelsus) has its own page.

Evidence: Extensive clinical research
Half-life: ~7 days
Sources: 5 cited

Is semaglutide FDA-approved?

FDA-approved as Ozempic (2017), Rybelsus (2019) and Wegovy (2021). Wegovy was also approved for lowering heart attack and stroke risk in 2024. Compounded copies aren't FDA-approved.

Overview

Semaglutide copies GLP-1, a gut hormone your body releases after eating. It's sold as Ozempic for type 2 diabetes, Wegovy for weight management and Rybelsus as a daily diabetes pill. In the STEP 1 trial, adults with obesity on the weekly Wegovy shot lost about 15% of their body weight on average over 68 weeks, versus about 2% on placebo. In the SELECT trial, it cut heart attacks, strokes and heart-related deaths by about 20% in people with heart disease and excess weight.

How it works

It switches on GLP-1 receptors in the pancreas, gut and brain. That helps the pancreas release insulin when blood sugar is high, slows how fast the stomach empties, and quiets hunger signals in the brain, so people feel full sooner and think about food less.

How long does semaglutide stay in the body?

About 7 days, so weekly shots build to a steady level after 4–5 weeks. Levels peak 1–3 days after a shot. The daily pill peaks about an hour after taking it.

What it's studied for

Type 2 diabetes blood sugar control
Weight management
Heart attack and stroke risk
Kidney disease in type 2 diabetes
Fatty liver disease (MASH)

Reported side effects

Nausea, vomiting, diarrhea or constipation, mostly when the dose goes up
Gallbladder problems
Pancreatitis (rare)
Low blood sugar when combined with insulin or sulfonylureas
Boxed warning: thyroid C-cell tumors seen in rodents. Not for people with a personal or family history of medullary thyroid cancer or MEN 2.

How should semaglutide be stored?

Unopened pens go in the fridge (36–46°F / 2–8°C) and must not be frozen. Once in use, an Ozempic pen can stay at room temperature or in the fridge for up to 56 days.

Sources

The studies and prescribing labels this page is written from.