How to inject semaglutide
A subcutaneous injection takes about ten seconds. The other five minutes are setup, site choice, and making sure the dose actually went in.
Semaglutide is a subcutaneous (under the skin) injection delivered once weekly. The pens are designed to be straightforward, but the difference between a smooth injection and a painful one usually comes down to a few details that nobody tells you in the leaflet.
This guide walks through the full routine — from pulling the pen out of the fridge to disposing of the needle — for both the Wegovy single-dose pen and the Ozempic multi-dose pen. The drug is the same; the pen mechanics are different.
Before you inject
The full injection routine
Let the pen come to room temperature
Pull the pen from the fridge 15–30 minutes before injecting. A cold injection stings significantly more than a room-temperature one. Do not warm it actively — counter time only.
Inspect the liquid
Through the pen window, semaglutide should look clear and colorless. If it is cloudy, discolored, or has particles, do not use it. Call the pharmacy for a replacement.
Pick a site and clean it
Approved sites: abdomen (at least 2 inches away from the belly button), front of thigh, or back of upper arm. Wipe with an alcohol swab and let it dry — wet alcohol is what causes most of the stinging.
Attach a fresh needle (Ozempic pens)
Wegovy pens come pre-assembled — skip this. For Ozempic, twist on a new needle until tight, remove both caps, and dial up the dose. Always use a new needle to avoid bent tips and infection.
Press the pen flat against the skin
For the Wegovy pen, you do not need to pinch — press the yellow window flat against the site at a 90° angle. For Ozempic, a gentle pinch of the skin can help, especially on thinner areas.
Press the button and hold for 5–10 seconds
Press the button firmly. You will hear a click when it starts and another when it finishes. Keep the pen against your skin for the full count after the second click — pulling out too early is the most common cause of an under-delivered dose.
Dispose of the pen or needle safely
Drop the entire single-use Wegovy pen, or just the used needle from an Ozempic pen, into an FDA-cleared sharps container. Never toss in regular trash.
The actual drug delivery — that 5–10 seconds — is the only part that matters for absorption. Everything else is comfort and safety.
Where to inject — and how to rotate
The three approved sites are the abdomen, front of the thigh, and back of the upper arm. The abdomen is the most popular because it is the easiest to see and reach, but rotating sites week to week is important for two reasons:
- Avoid lipohypertrophy. Repeated injections in the exact same spot cause lumpy fat tissue that absorbs the drug erratically. Rotation keeps absorption consistent.
- Avoid skin irritation. Even with rotation, an area that was used last week may still be slightly tender.
A simple system: divide the abdomen into four quadrants (above/below the belly button, left/right) and rotate by quadrant week to week. Use the thighs or upper arms as a fifth and sixth "spot" if you want more variety. Always stay at least two inches from the belly button itself, scars, and bruises.
What different injection sites feel like
Site by site comparison
Most people settle on a favorite after trying all three.
Easiest, most predictable
Quick to access, generous fat layer, and very consistent absorption. Most people start here. Avoid the 2-inch radius around the belly button.
Slower absorption
Slightly slower onset for some people, which can actually mean less nausea. Avoid the inner thigh and stay on the upper-outer portion of the front.
Hardest to self-inject
Most people need a partner to reach this site well. Absorption is comparable to the thigh. The skin is thinner — use a 90° angle and avoid pinching.
Common mistakes that ruin a dose
Avoid these
Injecting cold pen
Cold semaglutide stings sharply and may cause more bruising. Always let the pen sit out 15–30 minutes first.
Pulling out too early
If you do not hold the pen against the skin for the full count after the click, you can leave drug on the surface — under-dosing yourself.
Same exact spot every week
Repeated injections at one point cause lipohypertrophy, which makes absorption unpredictable. Rotate within and between sites.
Storage in plain language
- Before first use: refrigerate at 36–46°F (2–8°C). Do not freeze.
- After first use (Ozempic multi-dose pen): can stay at room temperature (59–86°F / 15–30°C) or in the fridge for up to 56 days. Discard after that.
- Wegovy single-use pen: use immediately after taking it out; can be at room temperature for up to 28 days before injection.
- Never freeze. Frozen semaglutide is degraded and must be discarded.
- Keep needle off until you inject. Storing with a needle on the pen lets air or contaminants in.
Common questions
Common Concerns
Do I need to aspirate (pull back to check for blood)?expand_more
What if I see a drop of blood after pulling out?expand_more
Should I inject in the morning or at night?expand_more
What if the pen runs out mid-injection?expand_more
Can I inject through clothes?expand_more
Keep exploring
Browse all GLP-1 guides or learn about side effects.