Vitamin C is like a “Little Black Dress” of skincare. It flatters every skin tone, everyone has it in at least one cosmetic in their cupboard, and it seems to be almost always a good choice regardless of the circumstances. It is one of the most well-researched skincare active ingredients with proven efficacy in
• increasing firmness of the skin
• keeping sunspots at bay
• fighting future signs of aging
• enhancing sunscreen protection
Almost every second brand has some kind of vitamin C serum with a “new form” or “new and better delivery system” or “the biggest percentage” of Vitamin C. So how to choose the serum that will work for you then? Should you go after the highest percentage? Is that it? Well, not really.
Sadly, not all formulations are effective. Some do not deliver an adequate quantity to the appropriate layer of the skin, while others do not chemically convert it to the biologically active form of Vitamin C in the skin. If using it in skincare was that easy, researchers wouldn’t be spending their lives studying the stuff. Let’s then go back to basics and try to understand what we should pay attention to when choosing a Vitamin C Serum.
Vitamin C comes in many forms, but not all are worth your money.
The name “Vitamin C” doesn’t always mean the same thing. There are many forms of Vitamin C. The most common form and the gold standard is Ascorbic Acid. L-ascorbic acid is the most biologically active form of Vitamin C and although it might be the most effective form available, it is also the least stable. What it means in practice is that it must be formulated and stored in very strict conditions. First of all, it requires a very acidic pH (below 3.5) to be effective. This is not a pH in which our skin feels good, so some serious skin stinging can happen. Secondly, it degrades with exposure to light and air and all of it happens within mere hours after initial exposure. When compromised it will not simply become inactive (and leave you with a useless serum), but it will degrade to a skin-irritating acidic by-product.
Don’t get me wrong, I’m not saying that all serums made with ascorbic acid are useless and dangerous. What I’m saying is that if you choose to purchase such a serum, you should make sure it is properly packed (ideally in an opaque airless pump bottle or in dark individually sealed single use capsules), correctly formulated (we will get back to this later on) and you should also accept the fact that it might sting your skin.
Some brands clearly state the percentage of ascorbic acid used in the final formula. It’s important to know that more is not always better. Ascorbic acid is most effective at 20 percent so there is no point paying more for any percentage higher than this, as it will make the serum more irritating, but not more effective. Most reputable brands use between 10 and 20 percent of ascorbic acid in their formulations. If you have sensitive skin is best to keep it safe and opt for serums with a percentage around 10 percent.
To address ascorbic acid’s stability issues, scientists came up with some less sensitive, less irritating and less pH dependent derivatives. Although still very powerful, they are unfortunately not as effective as ascorbic acid. They are still definitely worth trying though if you have a very sensitive skin, and if ascorbic acid doesn’t work for you.
Here are three that, in my opinion, are worth trying – Magnesium Ascorbyl Phosphate (MAP), Ascorbyl Glucoside and Ascorbyl Tetraiso-Palmitate.
What ingredient paring should you look for in your serum?
Do you remember when I said that a good Vitamin C serum must be properly formulated? Here is one of the most important tips on how you, the final customer, can easily check the formulation quality.
Vitamin C is an outstanding antioxidant, but for it to work best it should be paired with other, powerful antioxidants, so when their antioxidant powers are “depleted” they will be enthusiastically “borrowing” electrons from one to another and by doing it they will be renewing their potency. To understand it better, imagine two sets of puzzles that swap the last missing piece back and forth. By working together, they are more stable and have a higher efficiency than if working separately.
So, when choosing a serum, always look for one that has Vitamin E and some other powerful antioxidants like for example Feluric Acid or Coenzyme Q10.
Bottom line
The beauty of vitamin C is that there is a tremendous amount of research behind it. For now however, ascorbic acid is still the industry’s gold standard, and any other derivative available is still being compared to it. However, as you already know, using ascorbic acid on skin comes with a price tag of irritation and stinging. You are the only one who can decide if you are willing to go for it or if you prefer to choose a less irritating derivative. Whatever option you choose, remember that not all ascorbic acid serums are better than their derivative-based counterparts. A well-formulated serum based on a derivative could be much better than a poorly formulated or packed ascorbic acid serum.
