where should inject themselves with a b12 Injections at Home - Safety Guide for Self-Administration Best Vitamin B12 Injection Sites

Fatigue Fatigue is a common symptom of B12 deficiency, but evidence that B12 beyond the correction of deficiency has any benefits for energy is lacking

It is an intracellular metabolic-enzyme modulator, which is why its research read-outs are things like NAD+ levels and adipocyte gene expression, not how full you feel. That mechanistic distinction is the single most important thing to understand before looking at any dose number

Injections are necessary when your body cannot properly absorb vitamin B12 from your digestive system

Nausea is the most common complaint, affecting a substantial percentage of users, particularly during dose escalation phases

Last reviewed: May 28, 2026 Last updated: May 28, 2026 Written by: Jay Hastings, CEO of PlexusDx Jay Hastings is the CEO of PlexusDx, a precision health company focused on genetic testing, blood biomarker insights, and personalized wellness recommendations

The Upgrade Your Cells Have Been Waiting For NAD (nicotinamide adenine dinucleotide) is a coenzyme found in every living cell in the body