The Benefits of Vitamin C in Your Skincare Routine
There are SO many anti-aging benefits of Vitamin C. If you asked me for a BARE minimum skincare routine, I would absolutely demand that you incorporate a Vitamin C product.
Vitamin C safely benefits all skin types and tones, making it a no-brainer for every skincare routine.
Our bodies don’t naturally produce Vitamin C, yet it’s vital for healthy skin. As we age, our natural production of Vitamin C dwindles, so it’s imperative to incorporate it into our routines.
But what exactly makes Vitamin C so crucial for our skin? Let’s delve into the science.
1. Antioxidant Protection: Fighting Free Radicals
Free radicals damage our skin and can ultimately cause aging by harming DNA, collagen, and elastin. Vitamin C neutralizes these free radicals, stabilizes them, and prevents them from causing damage in our body.
We encounter free radicals all day in the world – pollution, sunshine, and even stress. Because we can’t escape the negative effects of free radicals, we need antioxidants to help combat and fight the damage they cause to our skin.
2. Brightening and Spot Reduction
Dark spots occur due to the overproduction of melanin in our skin. 
Vitamin C blocks this overproduction by suppressing the activity of the enzyme tyrosinase. Because tyrosinase is involved in the production of melanin, blocking its activity leads to a decrease in the intensity of dark spots.
Additionally, free radicals can also trigger inflammation and stimulate melanin production. UV radiation from the sun is a significant contributor to the formation of dark spots and hyperpigmentation. As a potent antioxidant, Vitamin C prevents this type of discoloration by combating free radical damage.
3. Collagen Boosting
Out of all the antioxidants, Vitamin C stands out because of the collagen-boosting benefits it provides your skin. Collagen is an essential protein that provides structural support to the skin, keeping it firm and youthful. Vitamin C improves skin elasticity and texture by promoting collagen production, resulting in a smoother and more radiant complexion. This is extremely beneficial for combating fine lines and wrinkles.
Furthermore, Vitamin C is essential in the process our skin goes through to make its own collagen. But not only that, it also inhibits enzymes from the sun that destroy our current collagen. So it’s a win/win/win on the collagen front.
4. Enhancing SPF Protection
And speaking of sun protection, don’t get me started on the importance of SPF. While Vitamin C cannot replace your sunscreen, it can enhance its effectiveness as a booster.
Vitamin C increases the amount of time your skin needs to turn red with sun exposure. This increases the overall length of time that your sunscreen is working for you.
Choosing the Right Form of Vitamin C
Did you know that “Vitamin C” is actually a blanket term encompassing many different forms? There is one active (pure) form of Vitamin C and many inactive forms.
Let’s go over a few of the most popular forms of Vitamin C and how to choose which is best for you.
Ascorbic Acid or L-Ascorbic Acid: The Active Form
This is the active form of Vitamin C that already exists in our body and skin. Ascorbic Acid is by far the most studied form of Vitamin C and has been shown to provide all the benefits listed.
As we age, it becomes more important to supplement with Ascorbic Acid as our bodies don’t store as much as they used to.
So, can you just drink a glass of orange juice for anti-aging?
Unfortunately, no. While consuming Vitamin C is great for your overall health, it won’t do much for increasing the amounts that get to our skin. That’s why applying Vitamin C topically is best for increasing the level in our skin.
So, should we all just use this form and call it a day? Well, you should consider some negatives of Ascorbic Acid before deciding.
Formulating Ascorbic Acid: The Challenges
One challenge with L-Ascorbic Acid is formulating it correctly to benefit the skin. The pH of the formula needs to be 3-3.5, and the concentration of Vitamin C needs to be 8-20%.
*Studies have shown that concentrations more than 20% Vitamin C aren’t absorbed into your skin and can just increase sensitivity. So more is not more.
Stability: Finicky as Heck
Ascorbic Acid is difficult to formulate with for other reasons, one of those being stability.
Studies have also shown that this form of Vitamin C can be more stable and effective when paired with ferulic acid and Vitamin E (tocopherol). Thus, you will often see formulations including these ingredients. Ideally, you would see 8-20% L-ascorbic acid paired with 1% Vitamin E and 0.5% ferulic acid.
Oxidization: Losing Efficacy
Another issue formulators need to overcome with L-Ascorbic Acid is the oxidizing process. A waterless or powdered form of ascorbic acid will be completely stable, but starts to oxidize once it is mixed with water.
A fresh vitamin C serum should be clear or cloudy white. As the serum starts to oxidize, it will turn yellow and dark orange. It’s still perfectly safe to use as it continues to oxidize, but as time goes on, the serum will slowly lose its effectiveness.
A good rule of thumb is to try to use a serum within 3-6 months. Once it turns a dark rust color or brown, it will no longer be effective.
Additionally, exposure to light and air will also increase the oxidation of Vitamin C. Therefore, another method to help prevent oxidation is packaging Vitamin C products in dark, opaque and airtight containers.
Using Ascorbic Acid in Your Routine
It only takes about 20-30 minutes for Ascorbic Acid to penetrate and be absorbed by your skin. After this amount of time, you’ve gotten the benefits. Studies have shown that this form of Vitamin C can actually stay in our skin at effective levels for 48 hours.
Inactive Forms of Vitamin C: Conversion Needed
You will find plenty of other forms of Vitamin C on the market, going by lots of complicated names. These other forms of Vitamin C are inactive and have an additional molecule added. Inactive forms need to go through a conversion process in our skin to ultimately become Ascorbic Acid (active).
Negative: Because this process needs to take place in your skin, it’s very difficult to know how much actual Vitamin C is getting to your skin.
Positive: The advantage of these other forms of Vitamin C is that they can remain stable in their formulation. Thus, they will not be at risk for oxidation and are much easier to formulate.
Tetrahexyldecyl Ascorbate (THD): Highly Popular
This form of Vitamin C has gained a significant amount of popularity in recent years.
THD is lipid (fat) soluble, instead of water soluble, theoretically making the absorption into the skin more effective. It is stable at a pH of about 5, thus will be less irritating than pure Vitamin C.
More studies are still needed on this type of Vitamin C, but the information that we do have has shown benefits for collagen production, skin brightening, and antioxidant protection. This form is effective in concentrations as low as 0.1% and is often recommended at a 2% concentration for maximum benefit.
It is important to note that the price and efficacy greatly depend on the formulation. One study found that THD was much more stable when formulated with acetyl zingerone.
If you are going to use this form of Vitamin C, it is often recommended to be applied twice per day to get maximum benefits.
My Personal Thoughts on THD: I’m not a chemist or a cosmetic formulator, but I’ll give my personal thoughts for what they’re worth. It’s hard for me to get behind something that has so little research showing its effectiveness or that it can even penetrate our skin. I have personally used THD and can agree that it is non-irritating and pleasant to use. However, I saw nowhere near the brightening skin benefits that I experienced while using pure Ascorbic Acid.
The Problem with Molecular Weight: THD
Many people believe that our skin cannot effectively absorb ingredients with a molecular weight over 500 daltons. Although it’s wise to use this more as a guideline than a rule, it is just a logical theory at this point.
Ascorbic Acid has a molecular weight of 176.12 g/mol.
THD has a molecular weight of 1,129.780 g/mol.
Whether or not you agree that 500 daltons is the maximum molecular weight that can penetrate the skin, there is no denying the massive molecule size difference of Ascorbic Acid vs. THD. The visual is like trying to fit an orange through a pasta strainer.
It’s impossible to know how well THD works without further studies. If you have used or would like to try THD I say go for it! It’s well tolerated for all skin types, and if you find benefits for your skin in using it, then that’s what matters.
Sodium Ascorbyl Phosphate: Great for Acne
This form of Vitamin C is very stable and can be formulated at a higher pH of 7; therefore, it will be less irritating on your skin. However, it is not as well absorbed as Ascorbic Acid, and the benefits are not as well studied.
In the studies we do have, Sodium Ascorbyl Phosphate has been shown to improve dark spots and boost collagen to some degree. In terms of anti-aging benefits, it will likely not work as well as pure Ascorbic Acid.
You would benefit from trying this form of Vitamin C if you have oily or acne-prone skin. This form has been shown to suppress the bacteria on our skin that leads to acne. Some studies suggest that Sodium Ascorbyl Phosphate may have anti-inflammatory properties, helping to soothe and calm irritated skin. This can be beneficial for individuals with sensitive or reactive skin types that cannot tolerate pure Ascorbic Acid.
Aminopropyl Ascorbyl Phosphate: New K-Beauty
A Vitamin C derivative created by combining ascorbic acid with a molecule called 3-APPA. This is a relatively new version developed by a Korean company.
There has been a study showing a reduction in age spots as well as wrinkle reduction. However, researchers still have very little data available on this form of Vitamin C.
I am eager to see more information come out about this form in the future, as we tend to see great innovation from Korean beauty.
If you are someone who is often at the forefront and likes to try new things, this might be of interest to you.
3-O-Ethyl Ascorbic Acid: Great for Sensitive Skin
This form of Vitamin C is much more slowly converted into its active form, making it more gentle for sensitive skin. It’s also formulated at a pH of 4-5.5, making it less irritating. Look for formulations of 0.5%-5%. Ethyl Ascorbic Acid is very promising but not fully proven, as the benefit depends largely on the formulation. It would be worth a try, especially if you are after Vitamin C’s skin-brightening effects.
How to use Vitamin C in Your Skincare Routine:
Tips and Tricks:
- As a general rule of thumb, you’ll want to apply your “thinnest” products first. Therefore, your light and watery products are often the first things to go on your skin in your routine. It makes sense, right? How can your watery toner penetrate your skin after you’ve applied a heavy moisturizer?
- Another general rule is that the closer a product is to your skin, the more effective it can be. This is common sense too, as the first product you apply is going to sit closest to your skin. For this reason, it is often recommended to put your Vitamin C products on first or as one of the first products in your routine.
- Depending on the form of Vitamin C you choose, you will apply it twice per day, or once per day. As mentioned earlier, THD is recommended twice per day to reach maximum efficacy, as Ascorbic Acid can stay in your skin for several days. When in doubt, follow the product recommendations on the bottle.
- It’s a myth that you can only apply Vitamin C in the morning. If it fits best into your routine to apply at night, that’s okay too.
- There are some ingredients you should not mix with Vitamin C, for example, Copper Peptides. It is a myth, however, that you cannot use Vitamin C with Retinol. In fact, they actually work well together. Be aware that if your Retinol (or other active ingredient) is currently irritating your skin, you would not want to introduce another potentially irritating ingredient at the same time.
- You need to be consistent with your Vitamin C use in the long term to see full benefits.
If you are still confused and want a basic breakdown of steps, I’ve got you covered.
Night Time Routine Steps:
Step 1: Start with double cleaning. Go in with a Micellar water, or Oil Cleanser, followed by a water based cleanser of your choice.
Step 2: Exfoliate (helps cellular turnover). You don’t need to do this step EVERY night, it should be ‘as needed’. Exfoliating too much can cause dryness, peeling, redness, and a compromised skin barrier. So don’t overdo it.
Step 3: Include serums that you want to use in your routine. This is where Vitamin C would come in, if you choose to apply at night.
Step 4: Eye cream if you choose to use one.
Step 5: Retinol or Retin A, or option to use after moisturizer if you’re sensitive.
Step 6: Moisturizer
Step 7: Face oil (if you’re very dry or it’s dry out) *don’t need to use every day
Day Time Routine Steps:
Step 1: Wash face with water, just water
Step 2: Serums, this is where you would include your Vitamin C product if you choose to use your vitamin C in the morning.
Step 3: Moisturize as needed
Step 4: Sunscreen (NON Negotiable)
Vitamin C Buying Guide:
Ascorbic Acid Product Recommendations:
•SkinCeuticals CE Ferulic, having worked in a plastic surgeon’s office, this was a favorite, and a cult classic. This product is a tried and true Vitamin C serum if you are looking for a no-brainer. It carries a VERY hefty price tag, so be aware of that.
•Maelove Glowmaker, This a pretty straight forward 15% Vitamin C serum for a great price! I like the inclusion of Aloe in the ingredients list, and this product advertises that it’s great for sensitive skin!
•Paula’s Choice C15 Super Booster, Another straightforward formulation. This serum is going to have all the necessary ingredients to be an effective Vitamin C product.
•Timeless 10% Vitamin C Serum, Available on Amazon making it a convenient choice if you don’t want to order from a medical office or direct website. It has both Vitamin E and Ferulic Acid, and comes in an airless pump. This serum has been popular for quite a while and has stood the test of time as a great affordable serum.
THD Product Recommendations:
•Sunday Riley C.E.O 15% Vitamin C Brightening Serum, Formulated with THD Ascorbate, a powerful, jar-stable, and highly targeted Vitamin C derivative that prevents and repairs the visible signs of premature skin aging.
•Revision Skincare C+ Correcting Complex, Infused with our patent-pending MelaPATH® technology that illuminates, refines, and rejuvenates, C+ Correcting Complex 30%® defends and corrects the skin-damaging effects of free radicals generated by Urban Dust and High Energy Visible light (HEV or blue light).
Sodium Ascorbyl Phosphate:
•Mad Hippie Vitamin C, Utilizing Sodium Ascorbyl Phosphate, an advanced and stable form of vitamin C, this serum works wonders on aging, sun damaged and acne-prone skin.
•U Beauty Resurfacing Compound, Brighten, resurface, tighten, renew, and equalize in a single step. Replacing up to eight products, it visibly improves texture, tone, pore size, congestion, and fine lines in as few as three days.
Aminopropyl Ascorbyl Phosphate:
•NeoCutis Bio Serum Firm, Warning this product is extremely expensive. It does have growth factors, peptides and other great ingredients that may or may not justify the price point.
•YBF Skincare Rescue Face Serum, Rescue Face Serum is packed with actives designed to quickly improve skin tone, restore skin elasticity, reduce the appearance of dark spots, lines and much more. It is also designed to augment the rest of your brightening skincare routine by enabling active ingredients to penetrate deeper into the skin, improving overall results of your entire skin care regimen.
3-O-Ethyl ascorbic acid:
•Summer Fridays CC Me Vitamin C Serum, Featuring two super-concentrated forms of Vitamin C, this serum helps deliver instant brightness while reducing the appearance of dark spots and hyperpigmentation. It is formulated with Niacinamide to restore skin and help minimize fine lines, plus Squalane to boost hydration.
Studies:
Study on THD (that included Ascorbic Acid):
https://pubmed.ncbi.nlm.nih.gov/11896…
Links to Studies on L Ascorbic Acid:
https://www.ncbi.nlm.nih.gov/pmc/arti…
https://pubmed.ncbi.nlm.nih.gov/12823…
https://pubmed.ncbi.nlm.nih.gov/11207…
https://pubmed.ncbi.nlm.nih.gov/23174…
https://pubmed.ncbi.nlm.nih.gov/18603…
https://pubmed.ncbi.nlm.nih.gov/30070…
https://pubmed.ncbi.nlm.nih.gov/22206…
https://pubmed.ncbi.nlm.nih.gov/15258…
Aminopropyl Ascorbyl Phosphate
Matsui, Mary S., et al. “Non-sunscreen photoprotection: antioxidants add value to a sunscreen.” Journal of Investigative Dermatology Symposium Proceedings. Vol. 14. No. 1. Elsevier, 2009.
Gillbro, J. M., and M. J. Olsson. “The melanogenesis and mechanisms of skin‐lightening agents–existing and new approaches.” International journal of cosmetic science 33.3 (2011): 210-221.
