[DOI] [PubMed] [Google Scholar] 17.Neelakantan H, Wang HY, Vance V, Hommel JD, McHardy SF, Watowich SJ

The Absorption Challenge The natural absorption of B12 involves a complex process: B12 from food binds to proteins and must be released by stomach acid It then attaches to intrinsic factor (a protein produced in the stomach) This complex travels to the small intestine where B12 is absorbed Finally, it enters the bloodstream for transport to cells This intricate pathway can be disrupted by numerous factors, including: Age-related decrease in stomach acid production Certain medications including proton pump inhibitors and metformin Gastrointestinal conditions like Crohn's disease Vegetarian or vegan diets with limited B12 sources Gastric bypass or other digestive surgeries Pernicious anaemia (autoimmune condition affecting intrinsic factor) The Injection Advantage B12 injections circumvent these potential absorption barriers by: Delivering B12 directly into muscle tissue Allowing immediate uptake into the bloodstream Bypassing the need for intrinsic factor and digestive processing Achieving higher blood concentrations than possible with oral supplements Providing 100% bioavailability regardless of digestive health This direct-delivery method explains why many people experience more noticeable benefits from injections compared to oral supplements

Importantly, AOD-9604 does not bind to growth hormone receptors, which is why it lacks the glucose-elevating and IGF-1-stimulating effects of full-length growth hormone
Our team can also advise on whether a blood test makes sense before your appointment
A provider-guided plan relies on a known, pharmacy-prepared source and the delivery form best suited to your goals, which removes most of the guesswork