best spot to inject b12 How Self-Inject Vitamin at Home Instruction Guide for Intramuscular (IM)

Repeat dose NRPT (nicotinamide riboside and pterostilbene) increases NAD+ levels in humans safely and sustainably: a randomized, double-blind, placebo-controlled study

B12 injections tend to be most useful for: Patients on GLP-1 medications (semaglutide, tirzepatide) who feel fatigue in early weeks Patients with low energy, brain fog, or mood symptoms Vegetarians or vegans (plant foods don't contain B12) Adults over 50 (B12 absorption drops with age) Patients who've had digestive surgeries (bariatric, gallbladder) that affect absorption They're generally safe B12 is water-soluble, so your body excretes what it doesn't use

Hunt A, Harrington D, Robinson S

Instead, it has to be converted by the body to a useable form which can take up to 48 hours