As a health professional you are expected to teach people with diabetes how to inject themselves with insulin if it is ordered by a doctor.
Subcutaneous injections, i.e. an injection where the tip of the needle penetrates just below the skin into the fatty layer beneath.
Insulin is injected subcutaneously using a short fine needle. The usual sites for injection are the thighs, hip area, abdomen or outer arms.

a) Diagram showing the penetration of a subcutaneous needle for injecting insulin. (b) Preferable injection sites for insulin. (Sources: (a) WHO/UNICEF, 2009, Immunization in Practice Modules for Health Workers; (b) The Open University, 2006, Living with Diabetes, Figure 4.2)