WHAT DOES VITAMIN C DO IN SKINCARE?
Vitamin C is a superstar anti-aging ingredient in skincare. It tackles anti-aging on lots of levels:
- Can increase collagen, which plumps up skin and decreases wrinkles
- Fades hyperpigmentation (brown marks like acne scars and sun spots)
- Acts as an antioxidant, protecting against free radical damage from UV, pollution and natural aging
Who wouldn’t want this, right? It does a bit of everything!
THE PROBLEM WITH VITAMIN C
The big problem with using vitamin C in products is that L-ascorbic acid is very unstable in water-based products. It turns into yellow dehydroascorbic acid (DHA or DHAA) and other products quickly. In one study at pH 3.52 and 25 °C in amber glass, 50% is gone in a week.
Luckily, DHA can convert back to L-ascorbic acid, and there’s no evidence that it’s bad for your skin (there’s actually a product with an accompanying non-peer-reviewed study that actually uses it as a way of getting vitamin C into your skin more easily). But there’s not a lot of evidence that it’s as beneficial either either, and it degrades further into products that can’t be turned back into L-ascorbic acid.
It’s well-documented that L-ascorbic acid can be stabilised by combining it with vitamin E and ferulic acid (plus it makes it work better). This is the approach used in serums from SkinCeuticals, Paula’s Choice, Timeless, Geek & Gorgeous, Maelove and Ausceuticals. However, if you want to DIY with this combo, it not only requires buying vitamin E and ferulic acid, but you’ll also have to get an emulsifier because vitamin E doesn’t play nicely with water.