What Is Vitamin C?
Vitamin C is one of the most popular skincare ingredients and for good reason. Vitamin C is a natural antioxidant, may help reduce the appearance of hyperpigmentation, and has been suggested to support collagen production in the skin.
There are many forms of vitamin C, including ascorbyl palmitate, mineral ascorbates, calcium ascorbate, magnesium ascorbate, and tetrahexyldecyl ascorbate. However, the most biologically active form of vitamin C is L-ascorbic acid. L-ascorbic acid is the form of vitamin C that is used in the body.
While some of the different forms of vitamin C are converted into L-ascorbic acid in the body, the best way to get the benefits from your vitamin C product is through using L-ascorbic acid.
So Why Not Just Use L-Ascorbic Acid?
The issue with L-ascorbic acid is that it is notoriously unstable. This means that it easily degrades when exposed to air, sunlight, and even when it is just sitting in a bottle.
This instability of L-ascorbic acid can make it a difficult ingredient to formulate with. There are some ways to improve its stability such as through including other antioxidants in the formulation such as ferulic acid or vitamin E, through packaging choices, or maintaining strict pH levels.
However, many companies choose to avoid the ingredient and opt for the less potent, more stable forms of vitamin C to use in their product.
The best way to ensure that the L-ascorbic acid product you are using is active and ready to give you the benefits you want is to make regular fresh batches. Some brands have taken up this model through powders and products that you mix at home. But why not try it yourself and avoid the price tag.
What Are The Benefits of Vitamin C?
L-ascorbic acid is a powerhouse ingredient that can help improve the appearance of the skin in multiple ways, making it an ideal product to bring into any skincare regime. Studies discussed in the Journal of Clinical and Aesthetic Dermatology have outlined the benefits of topical vitamin C treatments.
Their research found evidence that topical vitamin C may help diminish the visibility of pigmentation, is involved in the collagen production process, may be involved in inflammation, reduce the sun’s effects on the skin, and maintain skin barrier integrity.
Environmental factors such as radiation from the sun, UVA and UVB, pollution, smoking, and diet can put the skin in a state of oxidative stress. Oxidative stress produces an imbalance in the levels of molecules called free radicals. This imbalance may lead to damage of cells and tissues within the body.
Free radicals, also called reactive oxygen species or ROS, are a natural by-product of the body’s chemical processes. Think of them as your body’s waste. Free radicals can accumulate and create an imbalance.
This imbalance has been studied for its links with many diseases and its role in the aging process. As an antioxidant, vitamin C is thought to reduce the effects of oxidative stress by neutralizing the free radical molecules and rebalancing their levels in the body.
Vitamin C and sun damage
When skin is exposed to UV light, it can produce free radicals. Free radicals are involved in a cascade of events that have been suggested to reduce the amount of collagen the body produces, increase cellular damage, and may cause harm to the DNA within the cell.
The effects of free radicals on the skin result in the appearance of deep wrinkles, pigmentation, and loss of elasticity. These changes also tend to be associated with the natural decrease in collagen production and sun damage as we age.
As an antioxidant, vitamin C neutralizes the free radicals formed by exposure to the sun, giving vitamin C protective and restorative qualities against sun damage.
Sunscreen remains the most effective way of reducing the effects of sun exposure. Still, studies have shown that vitamin C can enhance the protective abilities of sunscreens and help fight some of the visible pigmentation associated with sun damage.
Evidence from several studies displayed the protective properties of vitamin C against the sun’s harmful effects. These studies suggest that vitamin C and another antioxidant, vitamin E, heighten the protective abilities against the sun in sunscreen formulations. Dermatologists might recommend using a vitamin C serum containing vitamin E before sunscreen to harness vitamin C’s ability to neutralize or rebalance the free radicals in the skin.
Vitamin C also helps to replenish vitamin E levels in the skin. Vitamin E, an antioxidant like vitamin C, has been studied for its involvement in immune function, maintaining skin health, and its abilities in supporting the skin to protect itself from UV damage.
As we age, collagen production decreases. From age 20, the amount of collagen produced reduces by 1% per year. As a molecule, L-ascorbic acid has been studied for its role in pathways that produce collagen in the body.
Collagen forms crosslinked fibers in the deeper layers of the skin which creates a net-like structure. It is thought that collagen may provide the skin with structure, firmness, or elasticity.
Vitamin C acts as a cofactor or a helper molecule in the body’s natural collagen forming process. Studies have looked at L-ascorbic acid’s ability to crosslink and stabilize collagen fibers. Vitamin C has also been investigated for its involvement in the production of a molecule called procollagen mRNA. This molecule signals the production of collagen and is responsible for signaling to the cell that collagen is needed.
While several studies support vitamin C’s involvement in the processes that produce collagen, research is ongoing as to whether skincare products containing vitamin C have significant effects in improving visible firmness and elasticity of the skin.
As the skin is the last organ to receive dietary vitamin C, topical L-ascorbic acid products such as powders and serums may be beneficial to improve the appearance of the skin. A study of vitamin C in skincare identified that topical L-ascorbic acid products increased L-ascorbic acid levels in the skin. The study also found that vitamin C products could improve the appearance of the skin at any age.
Hyperpigmentation and L-ascorbic acid
Hyperpigmentation occurs on the surface of the skin for a multitude of internal and external reasons. These can range from pregnancy or melasma, hormonal imbalance, and sun damage to genetic predispositions, injury, or inflammation.
Melanin is the molecule responsible for giving skin color or pigment, and the uneven production of melanin results in hyperpigmentation areas on the surface. Vitamin C works to reduce the visibility of pigmentation through inhibition of the enzyme responsible for producing melanin in the skin.
By inhibiting the irregular production of melanin, vitamin C, at the right \ and pH, can help minimize pigmentation’s appearance. Dermatologists might recommend concentrated vitamin C products alongside retinol and laser for pigmentation. Using vitamin C to reduce the appearance of pigmentation can take time and depend on the product’s strength and frequency of use.
It is crucial to use sunscreen alongside vitamin C products to avoid further pigmentation from the sun.
Vitamin C is thought to inhibit a molecule that activates pro-inflammatory cytokines. Cytokines are involved in immunity and help produce the inflammation reaction in the body to heal – think of healthy wound healing. In conditions where the skin is chronically inflamed, the cytokines react inappropriately, often working in overdrive. Currently, topical vitamin C products are being examined for how it is involved in inflammation, wound healing and post-inflammatory linked pigmentation.
Skin barrier integrity
The skin barrier includes the outermost layers of the skin and is essential for maintaining a healthy, clear complexion. It is responsible for protecting the skin’s deeper layers from damage, allergens, bacteria, and moisture loss. When issues with the skin barrier occur, it may suggest conditions such as atopic dermatitis or eczema.
Vitamin C has been used in combination with other skincare ingredients and dermatological therapies to treat conditions that affect the skin barrier. Vitamin C is thought to maintain the skin barrier by enhancing the ability of keratinocytes. Keratinocytes are a type of skin cell that produces keratin. Vitamin C helps to specialize the function of the keratinocyte.
What Should You Consider When Choosing A Vitamin C Product?
Stability of your vitamin C product
L-ascorbic acid is a highly unstable molecule. It requires a water-based environment, a low pH, and antioxidants to increase its ability to deeply penetrate the skin.
Those conditions are important for creating a stable and active vitamin C product. It is essential to understand why L-ascorbic acid requires these conditions when choosing a vitamin C product in order to find one that is effective and long-lasting.
L-ascorbic acid has a reduced ability to penetrate the skin at its natural pH which is a result of its molecule structure. L-ascorbic acid is a charged molecule and is hydrophilic. These two characteristics mean that L-ascorbic acid will readily bind to water molecules, making it hard for the molecule to pass through the skin’s hydrophobic layers.
Reducing the pH of a product to less than 3.5 or less makes it more acidic, allowing for L-ascorbic acid to penetrate deeper and be stable for longer. However, reducing the pH of the product may lead to sensitization of the skin, as the natural pH of the skin is around. It is important to know the concentration of the product (more on that below).
To create a more stable product that lasts longer, some formulations use different forms of vitamin C. This includes magnesium ascorbyl phosphate or ascorbyl-6-palmitate, which are more stable at a neutral pH. However, a study conducted by Duke University Medical Center found that these two substitutes did not increase the natural vitamin C levels in the skin.
Some formulations include other antioxidants to help stabilize the L-ascorbic acid. Studies have suggested that incorporating ferulic acid and vitamin E can increase stability and improve the product’s ability to penetrate deeply into the skin.
A study published in the Journal for Investigative Dermatology found that ferulic acid stabilized the formulation and increased the protective capabilities of vitamin C to the sun’s effects.
L-ascorbic acid will only stay active in skincare products for a short period once opened. Even well-designed products will experience this, as exposure to the air will oxidize the L-ascorbic acid. To increase a product’s longevity, look for powder formulations, products in vial form, or small product sizes. Look for products formulated with antioxidants such as ferulic acid.
Concentration is another critical element when considering which L-ascorbic acid products would best suit your needs. Some brands advertise a high level of vitamin C in their product, such as 100% L-ascorbic acid.
While it may seem appealing to have concentrated products, formulas with more than 20% L-ascorbic acid can irritate the skin. Most dermatological studies have found that a range between 8-20% produces the best results with limited irritation.
A study conducted by Duke University Medical Center found that the concentrations of L-ascorbic acid above 20% do not have increased skin benefits. The study determined that conversely, higher levels can negatively impact the skin’s condition. Sensitive skin types should use vitamin C products in the lower part of the range.
Synthetic or plant-based vitamin C
Occasionally brands won’t advertise the strength of the vitamin C content in the product but instead focus on the source. This lack of information regarding concentration tends to occur with formulations utilizing Kakadu plum, hibiscus, or other plant-based vitamin C sources.
The issue with plant-based sources of vitamin C is that they tend to be low in concentration and are generally unstable. The strength of L-ascorbic acid in Kakadu plum is about 2% which means it cannot affect the skin in any significant way.
The low concentration of L-ascorbic acid in plant-based sources and the instability of most natural sources is why most effective vitamin C products use a synthetic form of L-ascorbic acid in their formulations, including most clean beauty brands.
Vitamin C products
Many product types can deliver vitamin C to the skin, including gels, serums and powders. L-ascorbic acid is a water-soluble molecule that requires a low pH and the inclusion of stabilizers and antioxidants, which means that most L-ascorbic acid formulations will be in a water base or dried form. Some are formulated in an oil base.
L-ascorbic acid delivered in gel or serums is absorbed quickly without adding extra moisturizing products which makes them suitable for oily or acne-prone skin. They also work well with an established skincare routine, as they avoid disrupting a working regime. Powder forms of L-ascorbic acid prevent the need for many stabilizers. They reduce the risk of decreased effectiveness through exposure to the sun and air as the product becomes active only when mixed with water.
Other types of vitamin C
The type of vitamin C often varies between formulations. As a vitamin C source, L-ascorbic acid is the most well-researched source and the source that has shown the most benefits to the body. Other forms of synthetic vitamin C used in skincare are mineral ascorbates, calcium ascorbate, magnesium ascorbate, ascorbyl palmitate or tetrahexyldecyl ascorbate. The type of vitamin C and the type of product can have a significant effect on the efficacy of the product.
Studies have indicated that tetrahexyldecyl ascorbate might equal L-ascorbic acid in terms of effectiveness. Tetrahexyldecyl ascorbate is an oil-soluble form of vitamin C that works alongside other products such as retinol. In a review conducted by the Cosmetic Ingredient Review, evidence indicated that tetrahexyldecyl ascorbate is more stable in solution, less irritating, and able to penetrate deeper into the skin, making it a promising vitamin C treatment.
What Do You Need To Make Your Own Vitamin C Serum?
What you will need:
L-ascorbic acid powder
You can get this online or at some pharmacies and health food stores.
Don’t skip out on this ingredient and just use tap water. Distilled water has metal ions removed so that it won’t interact with the L-ascorbic acid.
You can find distilled water at most supermarkets, usually in the cleaning or laundry section. It is also sometimes called deionized water.
This one is important to balance the pH of the skin. Again another supermarket staple.
The best way to ensure the longevity of your vitamin C serum is by using an airtight and light blocking bottle.
Most pharmacies sell amber bottles with a dropper attachment lid. You can always wrap the bottle in some tin foil or fabric to minimise the light that can get in.
You can get pH strips from most pool shops and for this they don’t have to be super accurate, just enough to give an indication of the pH.
You will need these to measure out the right quantity of the powder.
Decide what strength vitamin C serum you want to make, 5%, 10% or 20%.
Calculate how much vitamin C powder you will need. This recipe makes about 0.68 fl oz of vitamin C serum, enough to last about the 2 weeks that the serum will remain stable.
Here are the measurements for the difference concentrations:
For 5% you will need 0.0018 oz of vitamin C powder
For 10% you will need 0.035 oz of vitamin C powder
For 20% you will need 0.071 oz of vitamin C powder
Add the measured vitamin C powder to your container
Add half of the distilled water or 0.34 fl oz and shake. Then add the second half of distilled water and gently shake the bottle.
Pop a drop of your serum onto a pH strip. Slowly add baking soda to the bottle and keep testing until the pH is around 3 or 4. You will need about 2-4 rice grains worth of baking soda depending on the concentration of the vitamin C you have chosen.
How Do I Know It’s Time To Make A New Batch?
In poorly designed products or formulations, the L-ascorbic acid can destabilize in the bottle, often leaving the product with a yellow hue. Oxidation is the process that causes this discoloration.
In poorly designed formulations, the oxidation can also occur on the skin’s surface, leaving the skin with a buildup of free radicals and acidic by-products or waste. This can affect the health of the skin mantle barrier, interact with other products and hasten the aging process.
So the best way to tell if it is time to make a new batch is if there is any discoloration or change in the consistency of the serum. However, the serum should last about 2 weeks.