Focus on: Vitamin C (L-ascorbic acid)

Have you ever heard of oxidative stress? Free radicals? And photo-aging?
All this doesn’t seem great to preserve the skin’s youth, does it?

The good news is that vitamin C can fight all these phenomena that make our skin looks dull!

Vitamin C is part of a category of expert anti-aging preventive ingredients called antioxidants.
Vitamin C is probably the most effective antioxidant to give an immediate boost to the skin. And it’s a real glow-giver!

But beware, all vitamins C are not equal.

The most efficient, the vitamin C L-ascorbic is sadly quite unstable and it needs some very precise conditions to deliver all its powerful antioxidant power to the skin.

What is Vitamin C:

Vitamin C is a great anti-aging ingredient that protects the skin against environmental aggressions that can make it look dull and age faster. It’s part of the antioxidant category, these very effective anti-aging ingredients. They really help to prevent the aging process and protect the skin.

Basically, antioxidants are molecules capable of preventing the skin oxidation. The oxidation phenomenon is essentially responsible for the production of free radicals, some unstable molecules which can cause chain reactions/ damages to the skin, sources of accelerated aging.

The oxidation of the skin is caused by several factors: stress, pollution, tobacco, infections, inflammations, sun exposure … in short, a normal, busy life!

Regarding vitamin C, unfortunately, even if you eat kiwis and oranges all day long, your skin won’t really benefit from the vitamin C they contain. To be effective, Vitamin C must be applied on the skin, topically.

Vitamin C benefits:

There are several vitamin Cs used in cosmetics but the most effective and the best known one is L-ascorbic acid. This specific vitamin C is intensely antioxidant: it protects the skin against the formation of free radicals which can result in accelerated aging.

Moreover, vitamin C helps to protect the skin from UV rays, not by replacing sunscreens (it does not protect the skin against UV rays) but by increasing their power by about 30%, in addition to its antioxidant action. It’s actually very beneficial for the skin to use a sunscreen after applying a vitamin C product because these two ingredients together have a real protective shield effect on the skin.

Vitamin C also helps to boost the production of collagen and elastin fibbers, which support the skin and give a plump aspect. So, it’s anti-wrinkles, indirectly.

As a bonus, it also helps to neutralize the enzymes that decrease the collagen present in the skin, day after day. It preserves the density of the skin and helps to maintain its bouncy appearance.

L-ascorbic acid also reduces the melanin oxidation, the molecule responsible for skin coloration. It reduces the appearance of darker spots or areas that makes the skin look dull (= hyperpigmentation), and it also moderates the production of tyrosinase, the enzyme that activates the melanin production.

Vitamin C is finally a glow booster because it helps to improve the quality of the structure of the skin as well as the cutaneous microcirculation. A good circulation allows the nutrients essential to the skin health to be transported in the upper layers of the epidermis and the skin can have this radiant healthy glow we all want! (So it’s perfect if you’re a smoker or if you live in a very polluted environment)

The issue with Vitamine C:

L-ascorbic acid is certainly the most effective and purest vitamin C but unfortunately, it’s also the most unstable form. Especially when it’s used in a cosmetic formula containing water, it has a big tendency to become inactive as quickly as it has arrived.

So in order to stay active and stable in a cosmetic formula which contains water, vitamin C L-ascorbic needs several conditions.

First, the formula has to be at an acidic pH, ie below 3.5. And the vitamin C L-ascorbic has to be at a concentration of at least 10% (up to 30%).

Also, to help stabilize L-ascorbic acid, many labs add one or more antioxidant ingredients to the formula, usually vitamin E and /or ferulic acid.
This combination of ingredients is indeed more effective to protect the skin but it also helps to stabilize the vitamin C in a cosmetic formula.
You can also add exfoliating ingredients to increase their penetration deeper into the skin (other acids, enzymes …).

Beware, however, most products based on L-ascorbic acid don’t have a very long life. Once opened, you need to use them quickly because after 6 months max, even stabilized, the vitamin C oxidizes and using oxidized vitamin C is useless. So it’s definitely something you want to avoid.
When you purchase a product based on vitamin C, it’s therefore better to ensure that it’s “fresh” for the same reasons.

In summary, for a vitamin C / L-ascorbic acid product to be effective in a water-based formula, it must:
– be in a formula with a pH of 3.5 or less,
– have a concentration of a L-ascorbic acid between 10 and 30%,
– be paired with other antioxidant ingredients in its formula (vitamin E, ferulic acid …) for more stability,
– be in a packaging which protects the formula from light/ UV rays and air (so no transparent glass),
– be used quickly (maximum 6 months after opening) and be “fresh” (really no need to stock up with this product).

How to use Vitamin C:

Because vitamin C has an antioxidant effect, I usually use it in the morning. Nothing wrong with applying a vitamin C product at night but since it boosts the effectiveness of sunscreens, it seems more logical to use it at the beginning of the day when the skin needs maximum protection.

Vitamin C has a 72h reservoir effect, meaning it remains effective on the skin even if you apply it once every 3 days. (Even if you rub the skin and if you wash it) However, I prefer to apply it every day to avoid losing my product (which as we’ve seen, has a limited life).

Also, since it requires a certain percentage to be effective, I prefer the more concentrated formulas that are usually in a serum form (more than cream, usually less concentrated and greasier). Ideally, I favour the vitamins C paired with vitamin E and / or ferulic acid, two other antioxidants that boost its effectiveness.

I usually apply it immediately after I’ve cleansed the face, on dry skin, because vitamin C is more effective in an environment with an acid pH and most of the serums and/or moisturizing creams have a pH that is slightly too high with the risk of diminishing its effectiveness. So I prefer to apply it before these, also because I want my skin to benefit from my vitamin C serum right away, without any other skincare products to “dilute” its effect.

I read here and there that it’s recommended to wait a few minutes after you’ve applied your vitamin C serum to let it absorb. Personally, I usually wait a bit before going on with the rest of my routine but the serum I’m using absorbs rather quickly into my skin, so my waiting time rarely exceeds 5 minutes (= the time it takes to brush my teeth, for example).

Product recommendations:

You can find my detailed review of the Geek & Gorgeous C-Glow vitamin C serum here.

– Vichy LiftActiv Peptide-C Ampoule Serum

You can find here my detailed review of the Vichy LiftActiv Peptide-C Ampoules Serum.

– Paula’s Choice C15 Super Booster

You can find here my detailed review of the Paula’s Choice C15 Super Booster.

– Maelove The Glow Maker Antioxidant Serum

You can find here my detailed review of the Maelove The Glow Maker Antioxidant Serum.

– Skinceuticals C E Ferulic Serum

You can find here my detailed review of the Skinceuticals C E Ferulic Serum.

– Drunk Elephant C-Firma Day Serum

You can find here my detailed review of the Drunk Elephant C-Ferma.

– Timeless 20% Vitamin C + E, Ferulic Acid Serum

A possible dupe for the Skinceuticals serum, the formula is extremely similar. It contains 20%  of L-ascorbic acid, 1% of vitamin E, 0.5% of ferulic acid, some hyaluronic acid and its pH is 2.4.
The main difference with the Skinceuticals serum is in the stability and the shelf life of the formula. You need to use it fairly quickly (2 to 3 months maximum) and the brand even recommends to place it in the fridge during use. It’s definitely not the most stable formula on the market, which can be problematic with this ingredient.
The texture is quite liquid, it’s quickly absorbed into the skin and doesn’t leave a greasy feeling on the skin. The formula is relatively simple and there are fewer natural extracts than in the Drunk Elephant serum.
The value for money is great, though! It retails for $15 (up to $25) for 30ml.

I also tried one of The Ordinary Vitamin C products, the Vitamin C Suspension 23%+ HA Spheres 2%, but it was not the most pleasant product to use.
The texture is grainy and quite gritty (you can feel the vitamin C powder inside the formula). It’s also greasy because it doesn’t contain water (which makes this product more stable than the others, though).
The brand recommends to mix it with their oily Resveratrol solution to bring in more antioxidants. That’s what I did but this combo was even greasier.
Regarding the feeling on the skin, it stings a little when you apply it, especially after a few days in my case, so it’s not the most pleasant product to use.
The result is there (it’s a brightening product, no doubt) but I think there are nicer options with vitamin C available on the market (like the products above), even if the price of this one is clearly unbeatable ($5.80 for 30ml).

Five vitamin C products I wouldn’t recommend:

– By Wishtrend Pure Vitamin C 15% with Ferulic Acid:
I explained why I wasn’t convinced in my dedicated review.

– Pixi Vitamin-C Serum:
I explained why I’m not a fan in my dedicated review 😉

– Klairs Freshly Juiced Vitamin C Serum:
A concentration of 5% L-ascorbic acid insufficient to be effective, a pH that is too high (3.8), the absence of antioxidants in the formula to stabilize L-ascorbic acid and a transparent glass bottle which doesn’t protect the formula from light and UV rays. All these aspects make me quite suspicious about the stability of this product…

– Vichy Liftactiv:
On a positive note, there is a concentration of 15% of L-ascorbic acid and the presence of vitamin E to stabilize it. But I note in the formula a very strong presence of denatured alcohol potentially irritating for the skin and the format of the product allows only 10 days of use, which certainly guarantees the freshness of the product throughout the course of the treatment but that makes it one of the most expensive vitamin C serums on the market: $28.50 for 10 days. So if you want to use it for 2 to 3 months, the necessary amount of time to benefit from all the positive effects of vitamin C, you would have to spend $200 to $250.

– Clinique Fresh Pressed Daily Booster pure vitamin C 10%:
10% of L-ascorbic acid, a formula suitable for sensitive skin and a packaging with a system that mixes vitamin C with the rest of the formula when you want to use it to ensure its freshness. Each bottle lasts 1 week. Note, the presence of silicone in the formula for those who are sensitive to it (like me).
But on the other hand, there are no other antioxidants in the formula to help stabilize the vitamin C and most of all, it’s the same problem as for the Vichy serum, it’s very expensive if you want to use it more than a few days. For 1 month, the treatment with 4 vials retails for $76.50, so if you want to do a treatment for 2-3 months, you will have to spend around $200.

Reviews sneak peeks: