b12 for injection Instructions MIC B12 from Fitish RX Vitamin B12 Injection, 1000mcg, 10ml,

In fact, one study found that peoples bodies absorbed about 49% of a 1-mcg dose of cyanocobalamin, compared to 44% of the same dose of methylcobalamin ( Conversely, another study comparing the two forms reported that about three times as much cyanocobalamin was excreted through urine, indicating that methylcobalamin may be retained better within your body ( However, some research suggests that differences in bioavailability between the two forms may be insignificant and that absorption could be influenced by factors such as age and genetics ( Unfortunately, recent research directly comparing these two forms of vitamin B12 is limited

But, serious side effects are rare

Biochemistry of B12-cofactors in human metabolism

Washing before AHK-Cu application removes this barrier layer