Injection site rotation: what the label requires, what lipohypertrophy is, and a plan that prints

"Rotate injection sites with each dose." Four words on every GLP-1 label, and not one more about how. The planner above turns that instruction into a dated list you can stick on the fridge. This guide explains what the rule protects against, what counts as rotation, and how to choose between the two patterns the planner offers.

What the labels actually say

The prescribing information for Zepbound, Mounjaro, Wegovy and Ozempic each contain the rotation instruction. Ozempic's adds: "the same body region" may be used, but "the injections should not be adjacent to each other". The Wegovy instructions for use say: "You may inject in the same body area each week, but make sure it is not in the same spot each time." Zepbound's instructions say: "You may use the same area of your body but be sure to choose a different injection site in that area."

The Zepbound vial instructions go one step further and say why: rotate "to reduce your risk of getting lipodystrophy (pits in skin or thickened skin) and localized cutaneous amyloidosis (skin with lumps) at the injection sites."

So the rule has two parts. Move the spot every time. The region can stay the same. Everything else, including how far to move and in what order, is left to you and your prescriber.

What goes wrong without rotation

Lipohypertrophy is a firm, rubbery, sometimes visible thickening of the fat under skin that has been injected repeatedly. The FIT injection recommendations (Frid 2016, PubMed 27594187), written for insulin users, describe it as the most common complication of subcutaneous injection and link it directly to failure to rotate, to reuse of needles, and to injecting into the same small area. It matters for two reasons. It is unsightly and slow to resolve, and drug absorbed from a lipohypertrophic site is absorbed unpredictably. The FIT paper's advice is to stop injecting into any such area until it has resolved, which can take months.

Lipoatrophy, the loss of fat leaving a dent, is the "pits in skin" the Zepbound instructions mention. It is rarer.

Localised cutaneous amyloidosis is a lump of misfolded protein at a repeatedly injected site, historically described with insulin. The Zepbound instructions name it as a second reason to rotate.

Bruising, tenderness and scarring are the everyday versions. Injecting into last week's bruise hurts more, bleeds more and heals slower. The Wegovy instructions say to avoid skin that is tender, bruised, red, hard, scarred or stretch-marked, and rotation is how you keep enough clean skin available every week.

What counts as a different site

The labels do not give a distance. FIT says injections should be at least 1 cm apart and that a site should be worked across in an organised way, such as quadrants, rather than at random. In practice a thumb's width is easy to judge and generous.

The planner encodes that. It divides each zone (abdomen left, abdomen right, thigh left, thigh right, upper arm left, upper arm right) into four spots (upper outer, lower outer, upper inner, lower inner) and advances the spot every time a zone comes round again. With four zones ticked and an 8-week plan, each zone is used twice, four weeks apart, at two different spots. With two zones and 16 weeks, each zone is used eight times and each of its four spots twice, eight weeks apart. The number of zones you tick is the number of weeks each zone rests.

The two patterns

Alternate sides, then move region. Abdomen left, abdomen right, thigh left, thigh right, and back to the start. This keeps you in one body region for two weeks at a time, which suits people who strongly prefer one region, and it means each side of that region rests a fortnight before it is used again.

Change region every week. Abdomen left, thigh left, upper arm left, then abdomen right, thigh right, upper arm right. Every week is a different region, so no region is touched two weeks running. It is the more conservative pattern for anyone who has had a reaction or a slow-healing site, and the simplest if a helper is available every other week for the upper arm.

Neither pattern is on the label. Both satisfy the label. Pick the one you will actually follow.

Sitting the plan alongside your titration

The planner does not know or care what dose you are on. That is deliberate: mixing dose logic into a site plan is how people end up reading the wrong column on injection day. Keep the dose schedule separate, whether that is the pharmacy label, your prescriber's written plan, or the injection schedule generator on the calculator site, and put the site plan next to it. The two share only the date.

One useful coincidence: the Zepbound and Wegovy labels both escalate every 4 weeks at the earliest, and a four-zone rotation also repeats every 4 weeks. If your zones are the same on every step-up day, that is a pattern, not a problem, but it does mean a step-up week will always land on the same region. If that region has been your most tender, tick a fifth zone to break the cycle.

Skin check before every injection

Rotation is a plan made in advance; the skin check is done on the day. Look at and press the planned spot. If it is tender, bruised, red, hard, scarred or stretch-marked (the Wegovy list), skip to the next spot in the same zone and note the change on the printed plan. If a whole zone is unusable, use the next zone in the plan and pick up the order next week. Missing a spot on the plan matters far less than injecting into damaged skin.

On the abdomen, stay at least 2 inches (5 cm) from the navel, as the Wegovy and Zepbound instructions say. On the thigh, stay in the middle third, front and outer. On the arm, the back only, and with a helper. The three site guides cover each in detail: abdomen, thigh, upper arm.

Using the printed plan

Print it and put it where the pens are: on the fridge door, or inside the carton lid. Tick the box after each injection and write the actual spot if you had to deviate. When the plan runs out, generate the next one starting from the week after the last row so the zones continue in sequence; the planner has no memory of the previous plan, which is deliberate, since nothing you type into it leaves your browser. Bring the completed sheets to follow-up visits: a record of where each dose went, alongside a dose log, is what a prescriber needs to make sense of a persistent site reaction or an unexplained change in response. The tools site has a matching printable dose log and side-effect diary.

If you already have a lump

Retire the area. FIT's recommendation for lipohypertrophy is to stop injecting there until it has resolved and to rotate more widely elsewhere. Tell your prescriber, especially if your response to the medication has been erratic, since absorption from a lipohypertrophic site is unreliable. A lump that is hot, painful, spreading, or accompanied by fever is not lipohypertrophy; it is a possible infection and needs to be seen.

Compounded vials

People drawing compounded semaglutide or tirzepatide from a vial rotate exactly as above. The only differences are that the concentration on the vial decides the volume, that the pharmacy's instructions replace the brand instructions for use, and that compounded products are not FDA approved and not interchangeable with Zepbound, Mounjaro, Wegovy or Ozempic. FormBlends' tirzepatide and semaglutide pages describe what its pharmacies dispense; the dose unit converter checks the arithmetic; the plan above handles the where.