Why pure L-ascorbic acid fails in India
L-ascorbic acid oxidises in the presence of heat, light, and air. At 42°C (common in Indian summers), oxidation rate doubles compared to 25°C. Studies show that L-AA serums stored at ambient Indian temperatures lose 60% potency in 3 weeks and 94% in 6 weeks. The orange-brown discolouration is visual confirmation of full oxidation — at which point the product is ineffective and potentially irritating.