Tag: Expired serum

Oxidized vitamin C serums can lose up to 25% of their potency within just three months of opening, dramatically reducing their effectiveness. This instability is a common concern for skincare enthusiasts, raising important questions about the safety and benefits of using a product past its prime.

Over 5.3 million Instagram posts use the hashtag #VitaminC, yet many users are unaware of the risks associated with this notoriously unstable ingredient. A serum can lose its potency and potentially cause harm when exposed to air, light, or heat, begging the question: is it harmful to use oxidized vitamin C serum?