US$ 20.60
aplb glutathione niacinamide cleansing oil 105ml – SoKoSkins APLB Glutathione Niacinamide Body Wash
Description
At 2.5 mg/mL (4 mL water): 10 units

We will talk more about why that makes no sense at all below but you should be aware here that serum B12 testing is very inaccurate and shouldnt be used to guide dosing

Copper peptides have been shown to enhance collagen synthesis through revitalizing sagging and hyper-pigmented skin in men and women
Studies suggest subcutaneous administration achieves 7085% bioavailability compared to oral routes, though oral protocols at 100150mg compensate for first-pass metabolism