Can all Vit C serums be stored in the fridge?

A lot of skincare actually benefits from being refrigerated. Vitamin C is especially great to keep in the fridge to prevent it from oxidizing and to maintain it’s shelf life. Sometimes vitamin c serums oxidize and turn dark orange after a few months which lessens it’s effectiveness. I keep my current vita c in a mini skincare fridge with some other serums, masks, and gel moisturizers. I’m not too sure about having it so cold that it may slightly freeze. It might alter the formulation from a constant cycle of freezing and thawing (even if it’s a small amount of freezing). I think regular fridge temp is your best bet. If you don’t want to pop it in the fridge, I’d say use it within 2 months of opening.

I would say pure L-ascorbic Acid would benefit from being stored in the fridge. The purer a serum is the more highly unstable it is. I have tried many vitamin C derivatives, while storing them in the fridge extends shelf life, storing them in normal room temperature was ok as well close to 6-8months depending on what vita c derivatives it is

Yep, all vit. C should go into the fridge. Keep it at the door - the ‘warmest’ place in the fridge.

yes I have heard that it's better use it in 2 months after opening

store vitamin C products in a fridge will slow down the oxidation process