Vitamin C Serum: A Simple Guide to Using It and Keeping It Fresh
Vitamin C is one of the most popular ingredients in skincare, and for good reason. It's an antioxidant that helps skin look brighter and more even. It's also one of the easiest ingredients to use the wrong way. Here's what's worth knowing.
Not all vitamin C is the same
The purest form, L-ascorbic acid, is effective but famously unstable. Air, light and heat can oxidize it, which is why some vitamin C serums turn yellow or orange over time. It also tends to be formulated at a low pH, which some sensitive skin finds irritating.
That's why many formulas use a vitamin C derivative instead. Our Vitamin C Serum uses 2% ascorbyl glucoside, a more stable form of vitamin C that's generally considered gentler on skin. It's paired with 1% ferulic acid and vitamin E, two antioxidants often used alongside vitamin C, plus hyaluronic acid and nourishing oils like jojoba, sea buckthorn and rosehip.
How to use it
- Use it in the morning. Apply a few drops to clean, dry skin after cleansing.
- Follow with moisturizer. Because the serum already includes hyaluronic acid and oils, a light moisturizer is often enough on top.
- Finish with sunscreen during the day. Vitamin C doesn't replace SPF, but the two belong together in a morning routine.
- Be consistent. Brightening is gradual. Give any new serum several weeks of daily use before you judge it.
Patch test first
Try a small amount on your inner arm or jawline for a day or two before using it on your whole face, especially if your skin is sensitive. The full ingredient list is on the product page if you want to check for anything you avoid.
Keep it fresh
- Close the cap right after each use.
- Store it away from sunlight and heat.
- Check the open-jar (PAO) symbol and write your opening date on the bottle.
- If the color or smell changes noticeably, replace it.
Every ZAKAVA order is made after you place it, so your serum starts its life when you order it, not months earlier on a shelf.