Injection site rotation

Injection site rotation means not injecting in exactly the same spot every week. GLP-1 pens are injected subcutaneously (into the fat layer under the skin), and the labels list three approved regions: the abdomen (avoiding a ~2-inch ring around the navel), the front of the thigh, and the back of the upper arm.

Why rotate

Repeatedly injecting the same spot can irritate the skin and, over time, cause lipohypertrophy — small firm lumps of fat tissue that form under frequently-used injection sites. Besides being uncomfortable, lumpy tissue can absorb medication less predictably. Rotation is the standard prevention: same region is fine, same spot is not.

How people actually do it

A simple pattern beats a complicated one:

• Region rotation: left abdomen → right abdomen → left thigh → right thigh, repeat.
• Clock method: stay on the abdomen but move around the navel like clock positions week to week.

The failure mode isn’t choosing a bad system — it’s forgetting where last week’s shot went. That’s why site logging exists as a feature in tracking apps (Glu included): a one-tap record on shot day means never having to guess.

Does the site change the effect?

For semaglutide, the label states the three sites can be used interchangeably — no clinically meaningful difference in absorption between abdomen, thigh, and arm. If a site consistently stings more or bruises, that’s a comfort issue worth solving, not an efficacy one.