Up until a week ago, I thought I’d found my holy grail skin brightener. I’d always used a vitamin C serum, but none quite as transformative as this one. As it turns out, there are risks that come with being transformative. When the serum oxidised, my skin started to become really rough and textured, it was showing more redness than usual, and I was breaking out like crazy. And while my skin has calmed down since I stopped using it, I’m still thinking about the effects of this wonderful, yet unstable, ingredient. I thought I’d share with you everything you need to know about vitamin C – what happens when vitamin C oxidises, what vitamin C derivatives are out there, and what products I have used and loved.
Benefits of vitamin C
There are many reasons that vitamin C is considered a wonderful skincare ingredient. Vitamin C is most well known for its brightening effect. It can fade dark spots and hyperpigmentation, create a luminous glow, and activate the synthesis of collagen. That’s not even all of it. Vitamin C has anti-inflammatory properties, and can help with the treatment of acne and rosacea by promoting wound healing. It’s also used for photo-protection – meaning, it fights free radicals caused by sun damage. In saying this, it does not absorb UV rays, so make sure you still wear sunscreen!
Oxidation of L-ascorbic acid
Here’s why it’s not so wonderful – L-ascorbic acid (the active, most potent, and most effective form) is unstable. When exposed to air and light, it breaks down and oxidises. The formulation of the product will then lose its antioxidant properties and could potentially become irritating to the skin. The vitamin C serum I was using was COSRX’s Vitamin C 23 Serum. And while the 23% ascorbic acid that it contains allows this serum to be transformative (my glow was gorgeous), the high concentration also means that it can cause increased sensitivities and irritation.
This is what to look out for with oxidation – the changing of colour (from colourless / light yellow to dark yellow / amber), changing of smell, or a thicker consistency. To slow down the process of oxidation, keep your vitamin C in a cool, dark place. Some even suggest storing it in the fridge. If you don’t want to worry about the process of oxidation, opt for a more gentle alternative to ascorbic acid and go with a vitamin C derivative.
Alternatives to L-ascorbic acid
Derivatives of L-ascorbic acid include sodium ascorbyl phosphate, tetrahexyldecyl ascorbate, ascorbyl glucoside, magnesium ascorbyl phosphate, and ethylated L-ascorbic acid. I know, what a handful. I haven’t used vitamin C derivative formulas before, but if you’d like a rundown on each one, the below video from Gothamista has you covered. Another alternative to L-ascorbic acid is sea buckthorn (hippophae rhamnoides). This seaberry is a source of vitamin C, as well as vitamins B & E, and other compounds that provide antioxidant benefits. Although it’s not as potent, this ingredient is much more gentle for your skin.
My favourite skin brightening products
If you’re still after an L-ascorbic acid formulation, I would highly recommend the Rohto Melano CC Serum. Because it comes in a plastic tube with a built-in dropper, the product is not able to be exposed to light or air. This stops the oxidation process. A favourite of mine that uses sea buckthorn is Isntree’s C-Niacin Toning Ampoule. It’s not as oily as the Rohto serum and it gives a subtle but noticeable glow. It also contains other highly beneficial ingredients like niacinamide, vitamin E, and hyaluronic acid. That’s a win, if you ask me. So, there you have it – everything you need to know about vitamin C.
Yours,
Kait x
Cover photo by Jess Loiterton