I have been using Apollo Expert Niacinamide 12% With Vitamin C 2% Face Serum for three months, and the one I bought from a local shop in Asansol was colourless. I am now in Chennai and planning to buy it online, but many reviews mention that the serum is brown. As I have very sensitive skin, could you please clarify whether the colour change is normal and how I can ensure the product is genuine and safe to use?
The serum may appear colourless or slightly yellow to light brown over time due to oxidation of vitamin C, which can occur with exposure to air or light. A mild colour change does not always mean the product is unsafe, but a very dark brown colour may indicate reduced effectiveness. As you have sensitive skin, it is best to buy from the official Apollo Pharmacy website or authorised sellers and perform a patch test before regular use. If you notice irritation, redness, or burning, stop using the product and consult a dermatologist.