Injection site rotation

Injecting the same spot again and again can cause lipohypertrophy: a build-up of fatty tissue under the skin that you may not see but can often feel as a soft or firm lump. The best evidence comes from insulin.

• Among 430 people injecting insulin, 64% had lipohypertrophy, and it was strongly linked to not rotating sites. Of those who rotated correctly, only 5% had it (Blanco et al., 2013).
• Insulin injected into these lumps was absorbed less, and far less predictably, than insulin injected into normal tissue (Famulla et al., 2016).
• International recommendations say not to inject into these areas, and that correct site rotation helps prevent them (Frid et al., 2016).

GLP-1 labels say the same in their own words. Mounjaro’s and Zepbound’s instructions ask you to rotate within the area you choose “to reduce your risk of getting lipodystrophy (pits in skin or thickened skin) and localized cutaneous amyloidosis (skin with lumps)” (Mounjaro, Zepbound).

The FDA-approved labels for Ozempic, Wegovy, Mounjaro and Zepbound list the same three areas, under the skin:

• Stomach (abdomen), at least 2 inches (5 cm) from the belly button (Wegovy, Zepbound). That’s the dashed ring on the map.
• Thigh, the front of the thigh in Wegovy’s instructions; MedlinePlus says the outer side of the upper thigh (MedlinePlus).
• Upper arm. Mounjaro and Zepbound name the back of the upper arm, and say another person should give the injection there.

Rotate every time. Each label says to change the site with each injection: you can stay in the same area, but use a different spot (Ozempic, Mounjaro). MedlinePlus adds at least 1 inch between sites.

Skip damaged skin. Don’t inject where the skin is tender, bruised, red, scaly or hard, into scars, or where it has pits, is thickened or has lumps (Wegovy, Zepbound).

Buttocks appear in insulin guidance (Embecta) but on none of these four GLP-1 labels. They’re on the map for people whose prescriber uses them. Your product’s label is the rule.

The map only shows your own history. The site you saved last gets a 1, the one before it a 2, then a 3; any other site you’ve used is shaded lightly. The list beside the map puts the sites you used longest ago first. It never tells you where to inject next.

The front view faces you, so your right side is on the left of the screen; the labels under each view say which side is which. Upper arms show on both views and count as one site.

Your sites are saved in this browser, on this device, and nothing is sent to Peptinote. Sites you log with a dose in the tracker show here too. Undo removes the last site you saved here, and Clear history deletes them all.