In fact, a 2008 study found that after taking a 1,000 mcg oral supplement, only approximately 1.3% (or 13 mcg) of B12 was absorbed into the bloodstream
If you are taught to self-administer, use the route, needle size, site, and technique provided by your care team
Many do well on oral supplements, but someone who is already symptomatic and confirmed low may recover faster with injections before switching to oral maintenance
Many clients report clearer thinking and steadier mood when levels improve, especially when combined with sleep, hydration, balanced meals, and movement
Before-and-after results are real, but gradual, structural, and built on consistency rather than an overnight transformation