vitamin b12 injection subcutaneous or intramuscular B-12 Kit - (Cyanocobalamin Injection) - Sola Pharma - Skin Pals™ B12 Injections for Energy: Benefits
Description
Thinner individuals may require shorter needles, while those with more muscle or adipose tissue may need longer ones to reach the muscle layer effectively

[30] What is the typical intramuscular maintenance dose

Therefore, lets think about an elephants butt instead

Ulanovskaya, O

If you are concerned about needles or are sensitive to them, then these alternatives may be suitable for you
