Vitamin C Serum for Face with Hyaluronic Acid, Ferulic Acid Anti Aging Serum | Pore Minimizer, Acne Scars, Dark Spot Remover for Face 20% Vit C facial serum DermaSkin by UMB Natures Journey (1 OUNCE

Q: Why is it yellow? Is this becuase of another ingredient or is it due to oxidation?

There are many other ingredients besides only vitamin C and ours freshly starts out yellowish orange. Our concentration is 20%. When in the vitamin C is in high concentration, the serum will have a yellowish color; but as it oxidizes, it will turn more orange over time. Only when it is a dark orange (brownish orange) should it be discarded as it will be less effective