Recommended Injection Sites for Hydroxycobalamin (Vitamin B12)
Hydroxycobalamin should be administered via intramuscular (IM) injection in the deltoid muscle of the upper arm for adults, or the anterolateral thigh for infants and young children. 1
Injection Site Recommendations by Age Group
Adults
- The deltoid muscle of the upper arm is the preferred site for routine intramuscular injections in adults, including hydroxycobalamin 2
- Use a 1-1½ inch, 22-25 gauge needle to ensure proper penetration into the muscle tissue 2
- The anterolateral thigh can be used as an alternative site if needed 2
Children (12 months to 18 years)
- The deltoid muscle can be used if muscle mass is adequate 2
- Use a needle size ranging from 22-25 gauge and 7/8 to 1¼ inches, based on the size of the muscle 2
- For toddlers with insufficient deltoid mass, the anterolateral thigh is recommended with a longer needle (usually 1 inch) 2
Infants (under 12 months)
- The anterolateral aspect of the thigh provides the largest muscle mass and is the recommended site 2
- Use a 7/8-1 inch, 22-25 gauge needle 2
Proper Injection Technique
- Insert the needle at a 90-degree angle for intramuscular injections 2
- The needle should be long enough to reach the muscle mass but not so long as to involve underlying nerves, blood vessels, or bone 2
- Before injecting, pull back on the plunger to check for blood return; if blood appears, withdraw and select a new site 2
Sites to Avoid
- The buttock should not be used routinely for injections due to potential risk of injury to the sciatic nerve 2
- Buttock injections have been associated with decreased immunogenicity of certain vaccines due to inadvertent subcutaneous injection or injection into deep fat tissue 2
- Avoid injecting into areas with lipohypertrophy (LH) or other tissue abnormalities 2
Special Considerations
- For patients with obesity, the deltoid site may be more likely to achieve proper muscle penetration compared to gluteal sites 3
- In females, especially those who are overweight or obese, standard 37mm needles may not reach muscle tissue in gluteal sites; deltoid injections are preferable 3
- For patients requiring frequent injections, proper site rotation is essential to prevent tissue damage 2
Alternative Administration Routes
- While intramuscular injection is the standard route for hydroxycobalamin as specified in the FDA label 1, research suggests intranasal administration may be an effective alternative for children, though this is not yet in standard guidelines 4
- High-dose oral vitamin B12 (1-2 mg daily) has been shown to be as effective as intramuscular administration in correcting deficiency, regardless of etiology, and may be considered as an alternative 5