GLP-1 Injection Sites: Scars, Stretch Marks and Rotation

The instructions answer the practical question

If stretch marks cover much of the abdomen, I would want someone to show me an appropriate injection site before using the pen. I would not infer that a mark is safe to inject through because the medicine is meant to reach the tissue underneath it.

For the Wegovy single-dose pen, the instructions explicitly say to avoid areas with scars or stretch marks. They also say not to inject into skin that is tender, bruised, red or hard². That instruction is more useful for choosing a site than speculation about whether absorption through a mark has been studied.

I would identify the exact device first

Wegovy’s prescribing information includes instructions for different presentations. I would use the leaflet supplied with the device I have, rather than assume a video for another pen applies unchanged.

I would check the medicine, prescribed dose and device name, then ask a pharmacist or clinician to demonstrate the sequence. If I cannot find a comfortable, suitable area, I would ask before injecting. I would not let embarrassment about asking turn into a guess about technique.

That includes asking which area another person can help with, if help is needed. A site named in the label still needs to be reachable and usable with the correct device technique.

The label offers more than the abdomen

The labeled injection areas include the abdomen, thigh and upper arm². I would ask about an alternative if the abdomen has extensive stretch marks, scars or irritated skin. I would not treat using a different approved area as changing the prescription.

The pharmacokinetic section reports similar semaglutide exposure across the listed injection areas². That comparison does not establish equivalent absorption through scarred, injured or stretch-marked skin. It compares the approved body areas under the conditions studied.

I would keep those two statements together: there are alternative approved areas, and the skin-selection instructions still apply within them. The general exposure finding is not a reason to disregard a specific precaution.

Rotation does not require inventing a complicated system

The instructions say the same body area may be used each week, but not the same exact spot as the previous injection². I would use a simple note if remembering the last site is difficult.

I would ask the team to show what counts as a different spot and which areas to avoid. I would not create a mandatory monthly rotation pattern or claim that everyone must cycle through four named body parts. The useful routine is one that follows the device instructions and is practical for the person using it.

I would also have the cleaning and disposal steps demonstrated. Knowing the correct area is only one part of using an injection device safely.

What the skin review can and cannot add

A review describes stretch marks, or striae, as changes in skin and connective-tissue architecture¹. It does not test semaglutide injections through those marks, measure drug absorption there or provide a reason to overrule the product instructions.

I would not turn a plausible anatomical explanation into “it probably does not matter.” An absence of a direct absorption study would not establish that advice. The current instructions already supply the practical choice: avoid the marked area and ask about a suitable alternative.

Nor would I equate every visible line with a surgical scar. If I am unsure what a particular area is, I would show it to a healthcare professional rather than diagnose its tissue properties myself.

If I am unsure a dose was delivered

I would not inject another dose to compensate for uncertainty. I would follow the device’s instructions for a delivery problem and contact the pharmacist, prescribing team or manufacturer as appropriate. I would explain what happened with the indicator, how long the device was held and any visible leakage.

I would also contact the team about a painful, persistent or concerning skin reaction. A problem with technique or skin deserves an answer rather than repeated attempts in the same uncomfortable area.

For me, the reassuring part is that help can be specific: identify the device, choose suitable skin in an approved area and demonstrate the process. I would rather ask for that demonstration than accept a confident online theory about what is happening underneath a stretch mark.