How to Inject Semaglutide (Wegovy/Ozempic): Step-by-Step Pen Guide

Before you inject: what you need

Required:

• Your semaglutide pen (Wegovy or Ozempic) — check the Wegovy dose escalation schedule to confirm which pen corresponds to your current dose step
• Alcohol swab (to clean the injection site)
• Sharps disposal container (for the pen after use)

Optional but helpful:

• Small adhesive bandage (if injection site bleeds slightly)
• Ice pack (to numb the injection site before injecting — reduces discomfort for some patients)

Pen preparation: what to check first

1. Check the pen before each injection

• Confirm the pen label matches your prescribed dose
• Check the expiry date
• Look at the solution through the viewing window: it should be clear and colourless to slightly yellow, with no particles

2. Temperature check

• Refrigerated pens (stored in the fridge) should be allowed to reach room temperature for 30 minutes before injection
• Cold semaglutide injection is more uncomfortable than room-temperature injection
• Do not freeze the pen; do not leave it in direct sunlight or heat above 30°C

3. Attach the needle (Ozempic only) Ozempic pens require attaching a new needle before each injection:

• Remove the paper tab from a new needle
• Push the needle onto the pen and screw clockwise until it feels secure
• Remove both needle caps (the outer cap and the smaller inner cap)

Note: Wegovy pens are single-dose auto-injectors with built-in needles — no needle attachment step required.

Selecting an injection site

Approved injection sites (from the prescribing label):

1. Abdomen (stomach area) — avoid the 2 inches around the navel
2. Thigh (outer thigh, middle section)
3. Upper arm (outer area) — only if someone else is injecting for you; self-injection in the upper arm is more difficult

Site rotation: Rotate injection sites with each weekly injection to prevent lipohypertrophy (fatty lumps from repeated injections at the same site). A practical rotation:

• Week 1: Right abdomen
• Week 2: Left abdomen
• Week 3: Right thigh
• Week 4: Left thigh
• Repeat

Avoid areas with scars, stretch marks, bruising, or skin irritation.

Injection technique: step by step

Step 1: Clean the injection site Wipe the injection site with an alcohol swab in a circular motion. Allow to dry completely (30 seconds) — injecting into wet skin with alcohol stings.

Step 2: Prepare the pen

• For Wegovy: remove the pen cap
• For Ozempic: after attaching the needle, perform a "flow check" (the first use of a new pen only: dial to the flow check symbol, hold the pen with needle pointing up, tap to dislodge air bubbles, press and hold the dose button until the counter shows 0 — a small drop at the needle tip confirms flow)

Step 3: Pinch the skin (for thinner patients) If you have limited subcutaneous fat at the injection site, gently pinch a fold of skin to lift it — this ensures the needle reaches subcutaneous fat rather than muscle. Not required if there is adequate subcutaneous fat.

Step 4: Insert the needle

• Place the pen firmly against the injection site — for Wegovy (auto-injector), align the base flat with the skin
• Press the pen firmly against the skin
• For Wegovy: press the injection button; the pen auto-inserts and delivers the dose
• For Ozempic: push the needle in at a 90-degree angle; press the dose button slowly and fully

Step 5: Hold for 10 seconds After pressing the button and hearing the pen click, hold the pen firmly against the skin for a full count of 10 seconds before removing. This ensures the full dose is delivered.

Step 6: Remove and dispose

• Remove the pen from the injection site
• Do not rub the injection site
• For Ozempic: replace the outer needle cap and unscrew the needle; dispose of the needle in your sharps container; replace the pen cap
• For Wegovy: dispose of the entire single-use pen in your sharps container

Common injection mistakes and how to avoid them

Mistake 1: Not holding for 10 seconds The most common mistake. Removing the pen too quickly causes part of the dose to leak back out. Always count to 10.

Mistake 2: Injecting into cold skin or cold medication Cold injections hurt more and may cause localised discomfort. Let the pen reach room temperature and allow the skin to warm up after the alcohol swab dries.

Mistake 3: Not rotating sites Injecting repeatedly in the same spot causes lipohypertrophy (fatty lumps). Rotate systematically. Note that lipohypertrophic areas absorb medication less predictably — if you've developed lumps at a site, avoid it for several weeks.

Mistake 4: Injecting into muscle Semaglutide should be injected subcutaneously (into fat), not intramuscularly. Intramuscular injection is more painful and changes the absorption profile. For very lean patients, pinching the skin prevents accidental IM injection.

Mistake 5: Pressing the button before the pen is against the skin The dose will eject into the air, not the patient. Always press the pen against the skin first, then press the button.

Mistake 6: Reusing Ozempic needles Needles are single-use. Reusing dulls the needle (increased discomfort), creates infection risk, and may block the needle tip, reducing dose delivery.

Dealing with injection site reactions

Normal: Mild redness, small bruise, minor swelling, or tenderness at the site. Usually resolves within 1–3 days. For a broader overview of GLP-1 side effects beyond injection site reactions, see our comparison guide.

Concerning: Growing redness, warmth, hardening of tissue, or signs of infection (expanding erythema, pus). Report these to your prescriber.

Strategies to reduce site reactions:

• Ensure the alcohol is fully dry before injecting
• Use a fresh needle each time (Ozempic)
• Rotate sites consistently
• Allow the pen to reach room temperature

Handling a missed or late dose

If you are more than 2 days early: Wait until the scheduled injection day.

If you are 1–5 days late: Take the dose as soon as possible, then continue on the usual weekly schedule.

If you are more than 5 days late: Skip the missed dose; take the next dose on the scheduled day. Do not double-dose. For the full dose schedule and how to restart after a longer gap, see the Wegovy dose escalation guide.

Pen storage

Before first use: Store in the refrigerator (2–8°C / 36–46°F). Do not freeze.

After first use (Ozempic multi-dose pens): Store at room temperature (up to 30°C / 86°F) or in the refrigerator for up to 56 days.

Wegovy single-dose pens: Single use; store in refrigerator until use; do not return to refrigerator after removal (Wegovy pens are for immediate use once removed and the cap is removed).

Summary

Semaglutide injection is straightforward with the correct technique. The critical steps are: allow the pen to reach room temperature, clean and dry the site, insert firmly against the skin, press and hold for 10 seconds after the click, rotate sites weekly. The most common errors — insufficient hold time, cold medication, and failure to rotate — are all easily corrected.