I’m also curious what type of Vit C. Ascorbic? The consensus has diversified after some time; one human being suggests ascorbic would be the worst, Some others say ascorbic is okay, others say Vit C can not be absorbed through skin to improve collagen but may have a brightening effect. https://7figurebm.com/how-to-make-vitamin-c-serum-from-orange-peel/