Serum are like magical drops that give nourishment to your skin. This is a dermatologically tested product, which means that it's been tested on humans.
From Amazon
Simple 10% Vitamin C + E + F* serum Booster Serum skin care product suitable for all skin types for youthful, glowing skin 30 ml
Justmylook
Simple 2% Vitamin C, 1% Vitamin E & 7% Vitamin F Booster Serum for All Skin Types 30ml