At clinical doses under supervision, the most common side effects are mild nausea in the first week (typically resolves by day 7 to 10), injection site reactions (redness, minor swelling, localized soreness lasting 24 hours), and occasional transient fatigue or mild headache in the first few days
Similarly, amino acid injections can offer immediate benefits, particularly for those deficient in certain amino acids or engaging in intense physical activity
Any discussion of laboratory applications refers solely to research environments and scientific workflows
Many other kinds of vitamin B 12 deficiency have since been found
But that process is slow, incomplete, and often produces scar tissue instead of healthy connective tissue