You wont absorb all of it, but such a high B12 injection dose ensures you have enough B12 circulating in your bloodstream at all times
That's why most research protocols build in a break between cycles, often called a washout period, to let the body reset before starting again
When I needed a receipt for FSA, it was readily available in my account
Vegetarians (especially vegans) are also given shots of B12 since their diet is low in animal products, the primary source of B12
By focusing on peptide identity verification , assay testing , HPLC analysis , LC-MS verification , and ISO 17025 laboratory testing , researchers can better evaluate product consistency and label accuracy
These are rare at the doses used in supervised clinical care and when they occur, they're typically mild and transient