Subcutaneous Injections
General Information
Subcutaneous Sites:
![]() Anterior View |
![]() Posterior View |
Indications for Subcutaneous Injections:
The onset of action for subcutaneous ( SC, SQ) injections is usually slower than for intramuscular (IM) injections (heparin is absorbed as quickly when given SC).
The medications given SC are isotonic, nonirritating, and water-soluble; examples are epinephrine, insulin, heparin.
The dosage that can be given SC is less than 1 ml.
Equipment:
The amount of adipose tissue determines the needle length and angle of insertion. Use what is needed to deliver the medication into the subcutaneous tissue.
In general, a 25g, 5/8 inch needle is inserted at a 45-90 degree angle. The needle-length should be 1/2 of the depth of the skinfold. A rule of thumb is that if the skinfold depth is 2 inches, inject using a 90 degree angle; if the depth is 1 inch, inject using a 45 degree angle.

Subcutaneous Compared to Intramuscular Injection:
![]() Subcutaneous Injection |
![]() Intramuscular Injection |
Subcutaneous Tissue:

Equipment for Subcutaneous Injections:
Tuberculin Syringe | ![]() |
|
Insulin Syringe | ![]() |
NOTE: These syringes are NOT interchangeable