subcutaneous administration of vitamin b12 injections homocysteine Injection Dose for Adults: 7 Dosage Facts How to Give B12 Injections

However, with severe vitamin B12 deficiency or absorption issues, healthcare professionals may recommend an intramuscular injection rather than an oral supplement

This injection is administered by a healthcare professional, typically in a hospital or clinic setting

References [1] Gastric bypass surgery

J Clin Neurosci

Its been 4 days since this started and still feel nauseous and dizzy, head feels foggy

many are marketed under familiar drug names but sold as "research-grade" products meant for laboratory use, not human treatment, and their ingredients, strength, and sterility can vary or be contaminated and mislabeled (goodrx.com)