Vitamin C For Skin: Ultimate Guide to its Benefits & Forms
Ah, vitamin C, the anti-aging wonder that makes an appearance as the star ingredient in countless serums.
But why? What makes it so magical?
Numerous studies (and basically anyone who’s ever used a good vitamin C serum before) have confirmed that it can perform skin wonders.
Topical vitamin C is known for its ability to brighten the skin, reduce wrinkles, treat hyperpigmentation (ie. age spots) and oxidative damage caused by UV (ultraviolet) exposure from the sun, and to also help minimize acne breakouts along with other inflammatory conditions.
Okay, it can seriously do all of that?
The reality is that if we want to slow the effects of aging, then vitamin C should be an integral part of your skin regimen.
But how does topical vitamin C even work? When we think of vitamin C, fruit usually comes to mind.
However, there are actually many different kinds available now thanks to modern developments, and I'll be outlining all of the benefits it can offer.
Vitamin C skin benefits for aging, acne, hyperpigmentation & other conditions
How vitamin C works
Normal human skin contains high levels of vitamin C, but it lowers in aged and photodamaged skin, making it an important part of the aging process.
When applied topically, vitamin C stimulates collagen production which is the main reason why It's so effective for aging skin.
Collagen is an important protein that provides structural support to our skin, making it a holy-grail for beauty.
Topical vitamin C skin benefits
Most studies are based on L-ascorbic acid (also known as ascorbic acid), so this is what I'll mainly be referencing when talking about vitamin C skin benefits.
1. Aging skin
Vitamin C both minimizes aging in the long-term and also treats existing wrinkles and sagging skin.
As we age, we slowly lose collagen. There are a number of reasons as to why this happens, but It's mainly attributed to unprotected exposure to the sun's UV rays.
After all, there's a reason why It's estimated that around 90% of aging skin is caused by sun damage.
Collagen helps to build our skin's structural integrity.
But, collagen isn't just important for aging. Collagen is a structural protein, and it works by lubricating the skin and giving it moisture. Think about your joints for a moment, could you imagine what they would feel like without collagen?
So why not just get a bucket of collagen and dunk your face into it? Unfortunately, this won't amount to anything.
The collagen molecule is simply too large to be absorbed into the dermis — our skin's thickest and deepest layer which is mainly made up of collagen.
Since this is the case, collagen must be stimulated through the use of other topical ingredients.
Enter vitamin C.
It's one of the best active ingredients to use in a serum for stimulating collagen production.
People with acne have been shown to be 40% lower in vitamin C than average.
Lipid peroxidation is one of the main causes behind acne breakouts, a process in which free radicals degrade the skin's lipids (ie. omega-3s and 6s).
Vitamin C reduces lipid peroxidation, helping to treat and prevent acne breakouts.
Vitamin C may also help treat minor acne scars, as it stimulates collagen production.
Read our acne article for more information on how to effectively treat acne.
Eczema (atopic dermatitis) is caused by an impaired epidermal barrier function — essentially what acts as a level of protection to the skin.
Low levels of vitamin C and ceramides, as well as collagen, are associated with eczema.
The now-famous ceramides are the most abundant lipids in the epidermis (outer layer of skin), and critical for maintaining the health of the epidermal barrier function.
Guess what? Vitamin C improves the epidermal barrier function by stimulating ceramides in the skin.
Low vitamin C may also cause histamine issues, which can worsen allergic symptoms associated with eczema.
This is perhaps one of vitamin C's most useful benefits.
Hyperpigmentation is a blanket term to describe discolouration of the skin, which is caused by the overproduction of melanin — the natural pigment that gives our skin its colour.
It can come in a few different forms, like age spots, melasma, or post-inflammatory hyperpigmentation:
— Age spots are caused by exposure to UV rays and repeated sun damage (aka tanning), and overtime as we get older, discolouration occurs.
— Melasma may be caused by sun exposure, hormone changes, and genetics.
— Post-inflammatory hyperpigmentation is different and occurs in response to inflammation from things like mechanically popping breakouts, rashes, wounds, surgery, etc.
— Dark circles under the eyes when not tired or dehydrated, are likely the result of genetics or inflammation caused by conditions likes eczema or psoriasis.
This ability of vitamin C also helps to brighten and even out the skin's tone.
Some people wonder if we get vitamin C from sun exposure. Unfortunately, we don't — otherwise, the sun wouldn't be as damaging to our skin.
When our skin comes into contact with UV rays, particles known as "free radicals" are produced which damages healthy skin cells.
Free radicals accelerate skin aging by degrading our collagen, resulting in wrinkles and loss of firmness over time.
This process is known as photoaging.
This is where antioxidants come in — and vitamin C is one of the best.
Not only does it have strong antioxidant properties, but vitamin C is also the most abundant antioxidant in human skin.
Exposure to UV light depletes the skin's vitamin C stores, which is likely why free radicals have a field day with our skin when we sunbathe.
Combining topical vitamin C with sunscreen is one of the most effective ways for warding off UV damage — and ultimately limiting all of the signs of aging skin from occurring.
Vitamin C also helps to maintain vitamin E levels in the skin, another important antioxidant.
So basically, without vitamin C, our antioxidant defenses are going to be pretty lack-luster.
Yeah, powerful stuff.
6. Dry skin
Vitamin C has actually been shown to help prevent TEWL (trans-epidermal water loss) by enhancing lipid production and regulating the skin’s moisture barrier, making it suitable for keeping the skin hydrated.
Since we know vitamin C stimulates ceramide production, they're known to increase hydration and prevent dry skin.
Do topical and dietary vitamin C have the same effect?
With all of the talk about vitamin C serums these days, have we stopped to wonder if actually consuming vitamin C rich foods has a similar effect?
Well, it turns out dietary vitamin C does have benefits for our skin. But, there's not a whole lot of data to really back this up.
Higher vitamin C intakes are associated with a lower likelihood of wrinkles and dryness as we age.
It's also been found that people who consume high amounts of vitamin C in their diet show little or no effect of topical vitamin C.
So basically, this means that dietary vitamin C could play just as an important role as topical vitamin C in warding off aging skin and inflammatory disorders.
Since acne sufferers have been shown to have 40% less vitamin C than people without acne, there's clearly a need for high vitamin C intakes.
The importance of vitamin C might be explained by the Kitavans, an indigenous group of people living off the coast of Papua New Guinea. They have virtually zero incidence of acne or blemishes.
While there are numerous factors contributing to their insane health (high-carb, low GI, dairy-free, mainly plant-based diet), some of their main food staples are sweet potatoes and fruits, which are very rich dietary sources of vitamin C.
While using it topically is clearly more science-backed for skin health, consuming vitamin C rich foods cannot be discounted and is obviously vital for the human body.
The best forms of vitamin C for skin
Not all vitamin C serums are created equally.
The land of vitamin C is vast. Many different forms exist now, and I'm going to be outlining the most effective and safest ones available.
There's L-ascorbic acid, and then there's everything else — known as vitamin C derivatives.
There are a plethora of vitamin C derivatives, which are created with a compound added (like magnesium, for example) as alternatives to L-ascorbic acid in hopes of preventing its degradation and irritation.
This is because certain forms of vitamin C derivatives are much more stable than L-ascorbic acid.
The downside of derivatives is they're often less effective than L-ascorbic acid, and they must be converted into L-ascorbic acid in the skin for them to provide similar skin properties.
I’m going to be listing the most proven derivatives, and talking about the benefits and side effects of L-ascorbic acid.
For each ingredient listed, I’ll also recommend where you can buy them.
1. L-ascorbic acid
L-ascorbic acid is the OG vitamin C — It's famously found in citrus fruits. It's also the most commonly used ingredient from the vitamin C family for both skin and health products.
It's tried and true, and arguably the most effective form of vitamin C available.
Now, L-ascorbic acid comes with some issues.
It's known for being highly unstable, requiring a very acidic pH level in a formula of around 3 in order to absorb into the skin.
This is a red flag.
Applying a product that's more acidic than our own skin (naturally about 4.5 – 5 pH) will alter its pH level, making it very irritating especially for people with sensitive skin.
To add to its pettiness, L-ascorbic acid also hates water.
It oxidizes very quickly when in contact with heat, air, and light after being formulated into skin products containing water as this activates it.
This is when it gets into some big trouble.
When L-ascorbic acid oxidizes, its molecule degrades and will eventually change from an antioxidant into a pro-oxidant.
This pro-oxidant is called DHAA (dehydro ascorbic acid), which is also very irritating to the skin.
You can tell when a vitamin C serum has oxidized based on its colour. If It's water-based, the serum should be clear.
If the colour has changed to yellow, orange, or even brown, it has oxidized. Toss it in the garbage. Yuck.
L-ascorbic acid serums should be contained in airless packaging, and not in droppers, or it will likely oxidize quickly.
L-ascorbic acid in oil-based formulas
However, all hope is not lost with this incredible skin-savior.
Powdered L-ascorbic acid can be added to anhydrous (oil-based) products without causing it to oxidize since It's not being dissolved in water, and oils don't have a pH level. This will also make it less irritating to the skin.
In fact, researchers have confirmed that L-ascorbic acid in an anhydrous formula is effective in increasing the production of collagen types I and III.
Powdered L-ascorbic acid can be added to facial balms, for example, to easily incorporate it into a skin care routine.
Where to get powdered L-ascorbic acid
Topical vitamin C is most effective when used in concentrations around 10%, although this can be increased over time.
2. Tetrahexyldecyl ascorbate
I know, tetrahexyldecyl ascorbate is a mouthful (now try saying it 3 times in a row). But, don't give up on this chemically-sounding ingredient just yet.
Tetrahexyldecyl ascorbate skin benefits
Tetrahexyldecyl ascorbate is a derivative of vitamin C.
The most important thing I want to mention about tetrahexyldecyl ascorbate is that It's oil-soluble. Obviously, in nature, vitamin C is water-soluble along with most of its derivatives.
This is a massive benefit because not only can it mix into your favorite oil-based facial serum effortlessly, but it means It's also incredibly shelf-stable.
Since It's oil-based, tetrahexyldecyl ascorbate penetrates into both the epidermis and dermis (the outermost layer and deepest layer of skin), which is often unheard of for topical ingredients in general.
The dermis basically provides support to the epidermis and elasticity to the skin, so It's important to also foster good health in there.
This means It's pretty bad-ass, as even L-ascorbic acid has issues penetrating into the dermis, caused by its water-soluble nature and oxidizing issues.
There’s even evidence to show that tetrahexyldecyl ascorbate converts into L-ascorbic acid when applied topically.
Since tetrahexyldecyl ascorbate reaches the deepest layer of skin, it may be the best vitamin C derivative available. Although, there isn't enough evidence to support this yet.
It turns out that tetrahexyldecyl ascorbate is also a fantastic ingredient to combine with L-ascorbic acid. Together, they've been shown to treat the signs of photodamage and significantly improve skin wrinkling after just a few months when used in an anhydrous formula.
Where to get tetrahexyldecyl ascorbate
The catch with tetrahexyldecyl ascorbate is It's expensive. It's also best to use it at a 10% concentration, but you can use concentrations upwards of 30% as It’s unlikely to cause irritation.
- Odacité – C For Colette (note: this product contains inflammatory oils)
- Eminence Organic Skin Care – Rosehip Triple C+E Firming Oil (note: this product contains alcohol)
- Making Cosmetics
3. Sodium ascorbyl phosphate
Like tetrahexyldecyl ascorbate, sodium ascorbyl phosphate is also a vitamin C derivative.
Sodium ascorbyl phosphate skin benefits
Sodium ascorbyl phosphate is especially suited for acne-prone skin and is one of the most effective topical vitamin C derivatives available.
It's water-soluble but also very shelf-stable, so you won't run into the same issue you would with L-ascorbic acid when mixing into a formula.
Sodium ascorbyl phosphate does still require a more acidic pH, however. Of course, any pH-related issues can be avoided by using an oil-based formula.
So how has it been shown to help your skin?
Sodium ascorbyl phosphate measures up to L-ascorbic acid and is effective in protecting against photodamage and sunburns.
On top of this, it also prevents lipid peroxidation caused by UV damage, protecting the skin's natural fatty acids and nutrients from degradation.
There's evidence that just a 1% sodium ascorbyl phosphate concentration has strong antimicrobial properties against the P. acnes bacteria associated with the development of acne.
A 5% sodium ascorbyl phosphate concentration was shown to be effective for nearly 77% of people with acne-prone skin.
It has the ability to reduce acne lesions by 49% within 8 weeks.
So if you're looking for an effective acne treatment – sodium ascorbyl phosphate is a great choice.
Where to get sodium ascorbyl phosphate
4. Magnesium ascorbyl phosphate
Very similar to sodium ascorbyl phosphate, magnesium ascorbyl phosphate is a water-soluble vitamin C derivative.
Magnesium ascorbyl phosphate skin benefits
Magnesium ascorbyl phosphate is very light and oxygen-stable in formulations and has a great safety profile. It’s much less likely cause itching, burning, or any of the nasties that can come along with topical L-ascorbic acid.
Magnesium ascorbyl phosphate is very effective in reducing inflammation associated with acne. It also decreases lipid peroxidation, helping to minimize acne breakouts.
Magnesium ascorbyl phosphate can help treat the hyperpigmentation disorder melasma.
Like L-ascorbic acid, magnesium ascorbyl phosphate is an antioxidant and helps to protect against photodamage.
Okay, all very exciting – but how does it measure up to L-ascorbic acid?
It turns out that magnesium ascorbyl phosphate is equivalent to L-ascorbic acid in stimulating collagen production. It does also convert into L-ascorbic acid in the skin.
So basically, high efficacy with little to no irritation? Magnesium ascorbyl phosphate is a winner.
Where to get magnesium ascorbyl phosphate
How to use topical vitamin C for maximum benefits
There are of course serums that exist, but as mentioned for topical L-ascorbic acid, it can go rancid quickly and potentially wreak havoc on your skin.
So you can either buy expensive or cheap vitamin C serums, but honestly, many of them (besides Mad Hippie's vitamin C serum) have pretty crappy base formulas (ie. formulated in silicones, preservatives like phenoxyethanol, etc) or have packaging that is likely to cause oxidation.
The alternative is using the powdered forms themselves.
Here's how you can use topical vitamin C powders:
To use the powdered forms of these topical vitamin C ingredients, they can be added to a cream or oil-based balm before you use them.
- Dissolve 1 part vitamin C powder to 9 parts serum (10% concentration).
- Apply to clean skin morning and night.
*Make sure to create this mixture each time you moisturize, and to not keep it stored in a bottle.
If you're new to using topical vitamin C or have sensitive skin, start out with 5% or less and gradually work your way up.
For more information on mixing vitamin C with other kinds of active ingredients, see the section below.
How to combine vitamin C with other actives ingredients
There’s a lot of speculation around which active ingredients can be used with topical vitamin C.
The concerns mainly comes from the fact that different types of active ingredients may require different pH levels.
Since L-ascorbic acid and the other derivatives mentioned (besides tetrahexyldecyl ascorbate) all require an acidic pH level when formulated with water, It’s hypothesized that these shouldn’t be combined with other products that may have a more alkaline pH level.
Vitamin C and niacinamide are great together, but their use has come with a lot of confusion.
Concerns around these two come from the fact that combining them can cause niacinamide to be converted into nicotinic acid (niacin), as it can react to acidic compounds such as vitamin C.
Nicotinic acid can cause redness in the skin.
However, niacinamide is only converted to nicotinic acid when exposed to long periods of high heat temperatures.
So, they're totally safe, especially when layering different products or combing vitamin C powder into a serum containing niacinamide.
Vitamin C and AHA can be used together since they both require similar acidic pH levels, but with caution. They might cause even higher skin irritation when used together compared to being used separately, especially on sensitive skin. This, of course, depends person to person.
Vitamin C and retinol can also be used together, but just like the AHA/vitamin C combo, it can cause irritation so those with sensitive skin should proceed with caution.
Vitamin C and vitamin E make an excellent duo. As two antioxidants, they have a synergistic effect in preventing photodamage and can be best utilized in sunscreen together.
Foods high in vitamin C
I think It’s important to also consider dietary sources of vitamin C, since it may have similar benefits to its topical counterparts.
I’ve listed the two most vitamin C rich foods found on Earth, which can be taken as supplements or added into smoothies in powdered form.
1. Camu camu berry
The camu camu berry is an Amazonian superfruit, containing the highest natural level of vitamin C in the world of any food.
With 2.4 – 3 g of vitamin C per 100 g of camu camu, it contains at least 45 times more vitamin C than an orange.
2. Acerola cherry
Acerola cherry is another superfruit with an insanely high amount of vitamin C.
It contains roughly 1.5 g – 4.5 g of vitamin C per 100 g of the fruit. Just one acerola cherry provides about 130% of your daily value of vitamin C.
Vitamin C FAQ
What are the best vitamin C skin benefits? 💆🏽
Vitamin C helps to treat and prevent an array of skin disorders, including hyperpigmentation, inflammatory conditions, and aging.
In the skin, it stimulates collagen production (the holy-grail for skin aging) and acts as an antioxidant against sun exposure.
Does vitamin C lighten skin? ✨
Yes, it does. It works to reduce hyperpigmentation by inhibiting the production of melanin which is responsible for producing pigment in the skin.
Does vitamin C help acne?
Vitamin C can be used as part of a treatment plan for acne, since acne-prone skin is much lower in vitamin C than average.
Aside from helping to correct this low level of vitamin C, it also reduces lipid peroxidation which prevents the breakdown of essential fatty acids that are important for limiting acne breakouts.
Do we get vitamin C from sun exposure? ☀️
Unfortunately, we don't get vitamin C from sun exposure. Vitamin D is the nutrient that our bodies produce.
Overexposure to the sun's UV(ultraviolet) rays damages our skin over time, leading to hyperpigmentation and aging skin.
What are the best vitamin C rich foods? 🍊
Certain fruits have been shown to be incredibly high in vitamin C. Some of which includes camu camu berry and acerola cherry. Camu camu berry, for example, provides around 45 times more vitamin C than an orange.