Rotation of insulin injection sites should not be random; it requires a strategic, systematic rotation plan.
- Major Rotation: Divide the body into zones and rotate weekly
The four preferred injection sites each have unique characteristics: Abdomen: Areas beyond one fist’s width around the navel.Insulin absorption here is fast and stable, making it ideal for short‑acting insulin.Avoid the belt line and scar tissue.
Outer upper arm: The middle 1/3 of the lateral upper arm.Absorption speed is second only to the abdomen.If self‑injection is difficult at first, ask family or friends to help locate the area.
Outer thigh: The upper lateral thigh, roughly from one palm’s width above the knee to the lateral area below the groin.Insulin absorption is moderate.Avoid the inner thigh, which has many blood vessels; accidental vessel puncture causes pain and potential injury.
Upper outer buttocks: The upper lateral area of both buttocks.This area has thick subcutaneous tissue and slower absorption, suitable for long‑acting insulin.Self‑injection can be challenging, so pay attention to posture and technique.
Major rotation technique:Think of the four areas as four “regions”. Use one region as the main injection site each week.
Week 1: Abdomen
Week 2: Upper arm
Week 3: Thigh
Week 4: Buttocks
Week 5: Return to abdomen, and repeat.This allows each large area sufficient time to recover, effectively preventing lipohypertrophy and other complications.
- Minor Rotation: Shift position within the same zone
Even within the same region, do not inject repeatedly at the exact same spot.
One‑finger‑width rule:Injection points should be at least one adult finger width (≈1 cm) apart, arranged like a grid.Inject row by row from left to right, or column by column from top to bottom.
For patients with poor memory or who find rotation complicated, an injection site marker card is highly useful.It is a card or sticker with many small holes marking recommended injection points.Place the card on the skin, inject through an unused hole, and switch to an adjacent unused hole each time.Once all holes on the card are used, rotate to the next region (per the major rotation plan) and use a new marker card.