Semaglutide
Also known as Wegovy, Ozempic, Rybelsus
A weekly injection that makes you feel full sooner and less hungry. It's the active ingredient in Wegovy and Ozempic.
Quick facts
- Status
- Approved medicine in the EU and US
- Evidence
- Approved (large phase 3 trials)
- Taken as
- Injection under the skin once a week (pre-filled pen); also a daily tablet
- Common sizes
- The approved medicine comes in pre-filled pens. Vials sold online (5–20 mg) are not the approved product.
- Category
- GLP-1 receptor agonist · weight & blood sugar
How it works
It copies a gut hormone called GLP-1. That hormone tells your brain you're full, slows down how fast your stomach empties and helps your body control blood sugar.
What it’s used for
- Weight loss (Wegovy) for people with obesity or overweight plus a health problem
- Type 2 diabetes (Ozempic, and Rybelsus as a tablet)
- Lowering the risk of heart attack and stroke in some people with heart disease
What the research shows
- Large clinical trials with thousands of people.
- People lost about 15% of their body weight on average after a little over a year with Wegovy.
- Weight usually comes back if treatment stops.
Side effects & risks
- Nausea, diarrhoea, vomiting and constipation — most common when the dose goes up
- Gallstones and, rarely, inflammation of the pancreas
- Losing muscle as well as fat if weight drops fast
- Not for use in pregnancy
Is it legal?
Approved in the EU (EMA), US (FDA) and UK. Prescription-only — use only under a doctor's supervision.
Storage & safe handling
- Keep unused pens in the fridge (2–8 °C); never freeze them.
- Use a new needle for each injection and rotate sites (stomach, thigh or upper arm).
- Follow your doctor's instructions and the patient leaflet — don't change the dose yourself.
- Get medical help for severe stomach pain, signs of an allergic reaction or persistent vomiting.
Open in PepTimerTrack your protocol, calculate how much to draw and get reminders — free.Open in PepTimer
Sources: EMA product information (EPAR) for Wegovy and Ozempic; FDA prescribing information for Wegovy.
Last updated 12 October 2026. Information — not medical advice. PepTimer does not replace a doctor. Many peptides are not approved medicines in the EU, UK or US. Talk to a qualified healthcare provider before starting, changing or stopping any treatment.
Last updated 12 October 2026. Information — not medical advice. PepTimer does not replace a doctor. Many peptides are not approved medicines in the EU, UK or US. Talk to a qualified healthcare provider before starting, changing or stopping any treatment.