u/Sensitive-Lake-7344

Every vitamin C serum I buy starts degrading around the 3-4 week mark, it turns yellow, sometimes orange, occasionally smells different. I know oxidized vitamin C is basically useless but I hate throwing out an expensive product. Has anyone actually found a solution that keeps it fresh for the whole bottle? Looking for real experiences not just what brands claim.

Every vitamin C serum I buy starts degrading around the 3-4 week mark, it turns yellow, sometimes orange, occasionally smells different. I know oxidized vitamin C is basically useless but I hate throwing out an expensive product. Has anyone actually found a solution that keeps it fresh for the whole bottle? Looking for real experiences not just what brands claim.