vitamin b1 b6 b12 injection benefits B Complex (3ml Ampoules) Vitamin B1,B6 & B12 Injection

They include pain or redness at the injection site, slight swelling or tenderness, mild diarrhea, and sometimes itching or a generalized feeling of body swelling

Thiamin supplements may also help for people who experience: malabsorption syndrome severe, prolonged vomiting gastric bypass surgery renal replacement therapy hyperthyroidism People who are pregnant, lactating, or use diuretics may also benefit from vitamin B1 supplements

May present with bloody stool, urgency, and perianal disease

B12 thins the blood and prevent stickiness which improves the cells from sticking together which can lead to a blood clot and reduce the risk of a stroke

So on the narrow question does it stop working after N weeks, the honest answer is: no published evidence says it does, and the mechanism actually argues against it