Injection sites
and rotation.
Rotating injection sites means not using the same spot twice in a row. Repeated injections in one place thicken the tissue, which changes how much is absorbed and makes the site sore. Move at least 2 cm from the last mark, work through your zones in a fixed order, and write down where each one went.
This page is about technique — where the needle goes and how to spread the load. It says nothing about what to inject, how much, or how often.
The five zones
Abdomen
The soft area either side of the navel, keeping roughly two finger-widths clear of it.
The most forgiving surface and the one with the most room, which is why rotation schemes usually start here.
Thigh
The front and outer thigh, in the middle third between hip and knee.
Easy to reach sitting down. Tends to be more sensitive than the abdomen.
Glute
The upper outer quadrant.
Awkward to see, so it is the zone most often reused by accident — the argument for writing it down rather than remembering.
Tricep
The back of the upper arm, the loose tissue between shoulder and elbow.
Little tissue on lean arms, and hard to reach on yourself.
Shoulder
The outer upper arm below the shoulder.
A small area, easily overused if it becomes the default.
These are the same five the app offers when you log a pin, so what you read here and what you tap there agree.
How to rotate
- 01Move at least 2 cm from the previous mark — about two finger-widths.
- 02Work through zones in a fixed order rather than picking one each time. An order you follow beats an intention you hold.
- 03Give a used spot time before returning to it. A fortnight is the common rule of thumb.
- 04Skip anything bruised, hardened, reddened, scarred or tattooed, and come back to it later.
- 05Write down where each one went. A rotation you cannot remember is not a rotation.
Keeping track of it
The last rule is the one that fails first, because it is the only one that needs remembering rather than deciding. pinning records the site with every pin, so the last one is on the screen instead of in your head.
What the app doesWhy do you need to rotate injection sites?
Because repeated injections in one spot change the tissue. It thickens and hardens, which alters how much is absorbed from that site and makes the area sore. Rotating spreads the load so no single patch takes every injection.
How far apart should injection sites be?
At least 2 cm from the last mark — roughly two finger-widths. Closer than that and you are effectively still using the same patch of tissue, even if it feels like a different spot.
How long before you can use the same injection site again?
Commonly around two weeks. The exact figure matters less than having an order you follow: enough zones in rotation means a spot gets its rest without you having to count days.
Which injection site absorbs fastest?
For subcutaneous injections the abdomen is generally the quickest, with the thigh and upper arm slower. This is a general property of the tissue, not a property of anything in particular you might inject.
What does a site that needs a rest look like?
Firm or lumpy under the skin, discoloured, or tender before the needle goes anywhere near it. Any of those means pick another zone and give that one longer than usual.
For informational purposes only — not medical advice