Where to Inject Semaglutide: Sites, Rotation and Technique

Semaglutide is a once-weekly subcutaneous injection. The labelling for the approved products specifies three sites, and they are interchangeable — no dose adjustment is needed when switching between them.

The three sites

All three are subcutaneous — into the fat layer beneath the skin, not into muscle. The injection sites guide covers the anatomy in more depth.

Rotation and why it matters

This is where most avoidable problems start. Repeatedly injecting the same spot can cause lipohypertrophy — a thickened, rubbery patch of fat tissue.

Lipohypertrophy changes absorption, not just appearance. A dose delivered into thickened tissue can absorb slowly or incompletely, which reads as the drug becoming less effective over time. The tissue is the variable, not the drug.

• Change site each week rather than favouring one.

• Move within a site too — shift by an inch or two even on the abdomen.

• Keep a record. A note or phone reminder beats memory on a weekly schedule.

• Inspect before injecting. Feel for hardness or thickening and avoid those areas.

• Avoid bruised, tender, scarred or reddened skin.

Technique

1. Inspect the solution. Clear and colourless. Do not use if cloudy or containing particles.

2. Let it come to room temperature if refrigerated — cold injections sting more.

3. Wash hands.

4. Swab the site and let the alcohol dry fully. Injecting through wet alcohol stings.

5. Follow your device instructions for needle attachment and any dose check.

6. Insert and deliver, then hold. Pens specify a hold time — count it out.

7. Withdraw and dispose in a sharps container.

Timing

The best time to inject guide covers timing across peptides generally.

What is normal afterwards

Mild redness, a small bump, brief stinging or a light bruise are common and usually settle within a day or two. Bruising is more likely on blood thinners.

Not routine: spreading redness, warmth, pain increasing over days, pus or fever. Those suggest infection and warrant medical assessment.

Common errors

For the drug itself rather than the injection, see the semaglutide side effects guide and the semaglutide dosage chart. The equivalent for tirzepatide is here.