Which site provides the most consistent absorption for insulin?

• A. Thigh
• B. Upper arm
• C. Buttocks
• D. Abdomen

Answer: (D)

Where insulin is injected affects how reliably it enters the bloodstream. The abdomen tends to give the most consistent absorption because the subcutaneous tissue there is relatively uniform in thickness and blood flow stays steady, so insulin uptake is predictable. In contrast, the thigh and buttocks have more variable fat distribution and activity of nearby muscles, which can slow or alter absorption, and the upper arm can also show more variability in blood flow. To keep absorption steady over time, it helps to rotate injections within the abdomen to avoid lipodystrophy, which can change how insulin is absorbed.