Vitamin C in skincare, all you need to know + products.

Vitamin C 

Vitamin C is present in our own skin, its function is to protect our skin from free radicals and oxidative stressors (ROS). These are generated by exposing your skin to UV light (such as the sun). This will damage your cells including collagen, which is the one keeping your skin nice and plump. By exposing your skin to the sun it reduces the skin’s own availability of vitamin C, therefore topical application can help to restore the balance. Even if you’d eat 20 oranges a day, that still does not make a significant difference in the levels of active vitamin C in your skin. To be fair though, if you’d eat 37 oranges a day it does help your skin against sunburn to a certain degree. 

Unfortunately, as we age our body is less able to fight off free radicals and Reactive Oxygen Species (ROS) therefore increasing the need for topical application.

L-ascorbic acid (LAA) 

L-ascorbic acid (LAA) is the active form of vitamin C, the other form is D-ascorbic acid and is not active and therefore not useful for skincare.
LAA is the most well known and well-studied form of vitamin C, however, it is unstable and hydrophilic. Because it is hydrophilic it bonds easily to water, making it more difficult to penetrate your skin. This is because the outermost layer of your skin is hydrophobic. To enhance the stability and skin penetration of LAA it is best to reduce the pH below 3.5 which is often done by combining it with other ingredients. I will give you some examples later on. 

The instability of LAA is worsened by exposure to light, it turns your serum from colorless to slightly yellowish transforming it into DehydroAscorbic Acid (DHAA) which is pretty much useless.
When your cream is opened for too long it will oxidize. When vitamin C oxidizes it means that two hydrogen atoms of vitamin C are lost and that makes it much pretty non-reactive. You don’t want that.

Antioxidant 

Vitamin C is a powerful antioxidant, it neutralizes the oxidative stress caused by the sun, pollution, and smoking. This is done by a process of electron transfer and/or donation. This is probably the most important part of vitamin C for your skin.
Antioxidants are necessary to neutralize oxidative stressors (ROS), vitamin C is effective against both UVA and UVB. 

To have a quick reminder:
– UVA destroys skin collagen, elastin, and proteins. UVA causes skin aging and possibly melanoma formation.
– UVB causes sunburn, ROS, and skin cancer.

 

I like to remember it by UVAging and UVBurning. Childish maybe, but it works!

As you might know, sunscreen will help protect your skin against UVA and UVB but sunscreens only block about 55% of free radicals that are produced by sunlight. Therefore it is important to use sunscreen combined with an antioxidant such as vitamin C (or others, but that’s not what this blogpost is about haha). 

Vitamin C protects your skin from UV light but not like sunscreen does. Vitamin C has a protective effect by neutralizing free radicals. Sunscreen works by blocking and/or absorbing UV light.
Therefore it is best to use them in conjunction with each other. It is best to use SPF daily and to apply a vitamin C product every night. You can also apply it both day and night of course. 

There are also sunscreens that contain vitamin C such as the Murad Invisiblur SPF, Neutrogena Rapid Tone Repair SPF, and the Peter Thomas Roth SPF.
The photos used are not mine, but the brand’s own. If you click it, it will direct you to their website. 

vitamin C in skincare
Invisiblur Perfecting Shield Broad Spectrum SPF 30 | PA+++
vitamin C in skincare
Rapid Tone Repair Moisturizer Broad Spectrum SPF 30
vitamin C in skincare
Peter Thomas Roth Max Mineral Naked Broad Spectrum SPF 45 Lotion

Anti-aging effects

Vitamin C is essential for collagen synthesis, which basically means putting it all together to form strong healthy collagen (science students, do not come for me please).
It influences collagen synthesis as well as stimulates the changes in the collagen molecule. It serves as a catalyzer for two enzymes that are responsible for stabilizing and cross-linking collagen molecules. 

Pigmentation

Your skin will darken when you are exposed to sunlight, which gives it more protection against sunlight. Also known as getting a tan. This sounds good, but this increased protection against sunburn is also linked to the development of melanoma (skin cancer).
Then there’s also hyperpigmentation, which are dark patches on the skin that are caused by excess production of melanin. 

Vitamin C is a potent anti-pigmentation agent as it inhibits the enzyme responsible for melanin formation. Therefore interrupts the key steps of melanin production. 

Anti-inflammatory 

Vitamin C can be beneficial to those with skin conditions like acne (vulgaris) and rosacea. It will also help with wound healing and prevent hyperpigmentation (see above).

Combining Vitamin C. 

Using vitamin C in conjunction with vitamin E can enhance its protective properties in fourfold.
A study has found that a combination of 15% vitamin C, 1% vitamin E, and 0.5% ferulic acid increased the efficacy of vitamin C up to eightfold. Product examples that are formulated like this are the Paula’s Choice C15 Super Booster, Drunk Elephant C-Firma, and the SkinCeuticals C E Ferulic. Seems like these 3  brands are on top of their research.
The photos used are not mine, but the brand’s own. If you click it, it will direct you to their website. 

vitamin C in skincare
Paula’s Choice C15 Super Booster
vitamin C in skincare
Drunk Elephant C-Firma Day Serum
vitamin C in skincare
SkinCeuticals C E FERULIC

Forms of Vitamin C that are more stable than L-ascorbic acid

Not all vitamin C derivatives are equal, and even worse not all derivatives are even tested on human skin. 

Magnesium ascorbyl phosphate (MAP)

The best of the class would be Magnesium ascorbyl phosphate (MAP), which is also pretty well researched. It’s very stable, and it increases the hydration levels in your skin. Because it is fat-soluble it has proper absorption into the skin. MAP has also been proven to be skin brightening, just like LAA as it inhibits the pigment forming enzyme in your skin. I could not find any research on whether or not MAP boosts collagen.
The photos used are not mine, but the brand’s own. If you click it, it will direct you to their website. 

Magnesium Ascorbyl Phosphate 10%

Ascorbyl Tetraisopalmitate 

Again a very stable form of vitamin C, which is pretty easy to formulate. Research shows it does convert into LAA but the efficacy is yet to be known. It has all other vitamin C benefits as listed under the general vitamin C/LAA part of this blog post. 

Ascorbyl Tetraisopalmitate Solution 20% in Vitamin F

Not a whole lot of research has been done into the following derivatives, even though that does not mean they’re not any good. We just don’t really know yet.

  • Sodium Ascorbyl Phosphate (SAP)
  • Ascorbic acid sulfate
  • Tetrahexyldecyl ascorbate (ATIP)
  • Ascorbyl glucosamine
  • Amino ascorbyl phosphate (which is a vitamin C plus a molecule called AAP)
  • Ethyl ascorbic acid (relatively new)
  • Tetraisopalmitoyl ascorbic acid – still under research.

That was it! If you have made it this far in my little nerdy research into vitamin C, thank you! I hope you enjoyed it.

Next up I will be discussing honey in skincare and haircare, which will be a whole lot shorter, to be honest. haha.

Have a nice day!
Love,
Romina

Ps: You might also like my blogpost on the REN Evercalm Day Cream.

Featured image (the first) sources: Drunk Elephant, Sunday Riley, Summer Fridays, Soskia

 

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