Human Skin - very thin. Muscle - highly vascularized. Fat - poorly vascularized.
__________________________________________________
__________________________________________________
SKIN Injections - ID - Intradermal
__________________________________________________
Muscle Injections - IM - Intramuscular
Muscle Injections - IM - Intramuscular
Typical IMs: Antibiotics, certain Vaccines
__________________________________________________
Fat Injections - SQ - Subcutaneous
The VIAL (or package insert) will tell you
WHERE that biological can be injected -
READ THE VIAL.