To make it clearer, heres a quick summary of the different ways you can check your B12 levels
Neoplasia 22 , 2232 (2020)
Features Package quantity: 307.18mg x 30 films Benefits: Main ingredients: How to use: Major Ingredients Yeast Extract (L-Glutathione 50, India) 42.32%, Pullulan, L-Ascorbic Acid, Hyaluronic Acid, Water-Soluble Milk Thistle (Milk Thistle Extract Powder (Poland), Polysorbate 20, Natural Fragrance (Natural Lemon Lime Scent), Enzyme Powder (Solid Content 1.5%/Modified Stevia, Glycerin, Xylitol, dl--Tocopherol Concoction Powder, L-Cysteine Monohydrochloride, Peppermint Extract (Egypt), White Tomato Concentrate Extract Powder, Gardenia Yellow, Hydrolyzed Elastin (France), Small-Molecular Fish Collagen, Selenium, Citric Acid Anhydrous, Riboflavin, Biotin *Contains Milk Ingredients subject to change at manufacturer's discretion
About IGF-1R IGF-1R is a transmembrane receptor tyrosine kinase that plays a central role in regulating cell growth, proliferation, differentiation, and survival, and is involved in both normal development and disease pathophysiology