Vit C - How To Delay Oxidation

I just wrote about this as a comment on someone else's post, but decided to create a more in-depth discussion for it in case others might find it helpful as well. ❤️ Licensed esthetician of 8+ years here. I am one of the few who advise against putting vitamin C serums in the fridge. My clients who do this usually end up being the least consistent with remembering to use it - you've probably heard the saying, "out of sight, out of mind". I'm definitely guilty of this myself! 😬 Manufacturers actually recommend storing it in a dark, cool area that is away from direct sunlight and heat. A medicine cabinet or drawer would be best, but again, if that means you're going to forget to use it, just know that not applying vitamin C is just as useless as oxidized vitamin C! Oxidation occurs most rapidly when the product is exposed to oxygen, so the ideal packaging for this type of product would be an airless pump container...even more so than the dark amber bottles we often see. However, you're more likely to find them in dropper bottles for ease of application (they usually have a very watery/thin viscosity). So quickly get out the amount that you need and get that top screwed back on tightly and as fast as possible! Also, be careful to not pump air into the bottle when using the suction dropper. In addition to your face, make sure you are also bringing the product to your neck and decollete. I start to get more generous with the amount and areas I apply it to when I start to see the first signs of oxidization occurring. If you're using it daily and following the advice above, you'll have a much greater chance of finishing the bottle before much oxidation has occurred. As a side note, it's very important for l-ascorbic acid (the form of vitamin C most clinically proven for efficacy) to have the correct pH and delivery system as it is a water-soluble ingredient. You'd think this would be a given during the research & develop phase, but there's surprisingly many products that are emulsified with oils that prevent the l-ascorbic acid from even penetrating. If the other ingredients are causing it to not go where it needs to go, then the benefits they are promoting aren't going to apply. Hope this info helps someone out! Let me know if you have any questions - I could talk about antioxidants all day long lol. Fun fact, my favorite vitamin C derivative is actually tetrahexyldecyl ascorbate. It's oil-soluble, much more stable than l-ascorbic acid, and found to be just as affective in multiple clinical trials! 🍊