What’s a vitamin C serum?
If you have your head in the skin care game, you’ve likely heard of vitamin C serums.
Vitamin C is touted as one of the best anti-aging ingredients on the market — and the key to maintaining a smooth, even, and glowy complexion.
Although you’re probably getting vitamin C in your diet, there’s no way to guarantee it’s going straight to your skin. Using serums and other topical products is the most direct way to reap these benefits.
Benefits
There are plenty of benefits to using vitamin C on your skin. They include:
- safe for most skin types
- hydration
- brightening
- reduce redness
- reduce hyperpigmentation
- reduces the appearance of under-eye circles
- promotes collagen production
- may help prevent sagging
- may protect against sun damage
- may soothe sunburns
- may help wound healing
1. It’s safe for most skin types
Vitamin C has an excellent safety profileTrusted Source. Most people can use topical vitamin C for an extended period of time without experiencing any adverse reactions.
In rare casesTrusted Source, people who have hypersensitive skin may experience minor irritation.
2. It’s hydrating
According to a 2017 research review, most healthy skin and organs contain high concentrations of vitamin C, suggesting that vitamin C accumulates in the body from circulation.
Review authors noted that topical vitamin C penetrates the skin best in the form of ascorbic acid.
Magnesium ascorbyl phosphate, another vitamin C derivative used in skin care, has been shown to have a hydrating effect on skin, according to a 2013 reviewTrusted Source. It decreases transepidermal water loss (TEWL), allowing your skin to better retain moisture.
According to a 2019 studyTrusted Source, an antipollution, antioxidant serum containing Deschampsia antarctica extract, ferulic acid, and vitamin C reduced TEWL by 19 percent, improving the skin barrier function.
3. It’s brightening
Vitamin C can help fade pigmentation (more on this below!) and smooth the skin’s surface to reduce dullness. This gives skin a youthful glow.
A 2017 reviewTrusted Source notes that vitamin C application has been shown to impede melanin production, the pigment responsible for skin color. This can help fade dark spots and general dullness that prevent you from getting that dewy glow.
4. It helps reduce redness and even out your skin tone
Vitamin C has also been shown to act as an anti-inflammatory agent through its antioxidant capacity, according to a 2015 reviewTrusted Source. This means it soothes your skin and reduces puffiness, letting your face shine through.
Vitamin C’s anti-inflammatory action may helpTrusted Source:
- neutralize free radicals that cause oxidative damage
- optimize the immune system to discourage inflammatory immune response
The anti-inflammatory properties of vitamin C can also help reduce redness, which in turn can create a more even complexion. The combined reduction of dark spots, redness, and irritation make for a clear, smooth skin tone.
5. It helps fade hyperpigmentation
Since it impedes melanin production, vitamin C can actually fade hyperpigmentation.
Hyperpigmentation — including sunspots, age spots, and melasma — occurs when melanin is overproduced in certain areas of the skin. It can also happen in areas where acne has healed.
Vitamin C inhibits melanin synthesisTrusted Source by downregulating the activity of an enzyme known as tyrosinase. It’s widely used in dermatology for depigmentation of hyperpigmented spots on the skin.
It’s also been used for treatment of gingival melanin hyperpigmentation (gum hyperpigmentation), though studies are limited.
6. It reduces the appearance of under-eye circles
Vitamin C serums can help smooth out fine lines by plumping and hydrating the under-eye area.
Although vitamin C is more effective at reducing overall redness, some people say it can help alleviate discoloration associated with under-eye circles.
According to a small 2009 studyTrusted Source, vitamin C in the form of 10 percent sodium ascorbate was found to improve dark circles of the lower eyelid after 6 months of use by thickening the eyelid dermis and concealing dark coloration due to congested blood.
Some other ways to help get rid of under-eye bags include using a cold compress and adding retinol to your skin care routine.
7. It promotes collagen production
Collagen is a naturally occurring protein that depletes over time. Lower levels of collagen can lead to fine lines and wrinkles.
Vitamin C is well known for boosting collagen productionTrusted Source through the process of collagen synthesis. In fact, collagen synthesis can’t happen without vitamin C.
This is because vitamin C is the essential cofactor for the two enzymes required for collagen synthesis:
- prolyl hydroxylase, which stabilizes the collagen molecule
- lysyl hydroxylase, which provides structural strength
8. It may help prevent skin sagging
Collagen production is tied to skin elasticity and firmness. When your collagen levels begin to drop, your skin may begin to sag.
Applying a vitamin C serum may boost collagen production, resulting in an overall tightening effect, reports a 2017 reviewTrusted Source. This is true for sagging due to natural aging, oxidative stress damage, or extreme weight loss.
This means it can help reduce the appearance of sagging skin, making your skin look firmer and more toned.
9. It protects against sun damage
Excessive exposure to oxidant stress via pollutants or UV irradiation is associated with depleted vitamin C levels in the skin. Vitamin C levels are also lower in aged or photodamaged skin, though researchers are unsure whether this is a cause or effect.
Sun damage is caused by molecules called free radicals. These are atoms with a missing electron. Free radicalsTrusted Source search for other atoms from which they can “steal” an electron — and this can lead to significant damage to the skin.
Vitamin C is rich in antioxidants. Antioxidants protect healthy skin cells by “giving” these free radicals an electron, rendering them harmless.
10. It may help soothe sunburns
In addition to minimizing redness, vitamin C accelerates cell turnover, according to a 2013 reviewTrusted Source. This replaces the damaged cells with healthy new ones.
Topical application of vitamin C, in combination with vitamin E and other compounds, has also been shown to reduce injury due to UV irradiation (aka sunburn), notes the above 2013 review. This combination also decreases the inflammation induced by excessive UV exposure.
It’s important to note that researchers found that vitamin C alone is only minimally effective at reducing sunburn on its own.
11. It generally helps boost wound healing
Given its effects on sunburn, it should be no surprise that vitamin C application can speed up overall wound healing. Healthy wound healing reduces your risk of inflammation, infection, and scarring.
A 2017 reviewTrusted Source found that vitamin C supplementation had a positive effect on gene expression in human skin fibroblasts, including:
- increased mitogenic stimulation, or cell proliferation
- increased cell motility, or the spontaneous movement of a cell from one location to another by consumption of energy
- faster repair of damaged DNA bases
This is in part because wound healing is associated with collagen formation, and vitamin C boosts collagen production.
How to use a vitamin C serum
Although topical vitamin C is generally well tolerated, all skin products have the potential to cause side effects. You should always do a patch test to assess your risk of allergic reaction. Here’s how:
- Select a small area of skin that’s easy to conceal, like your forearm.
- Apply a small amount of product and wait 24 hours.
- If no side effects occur, you can apply to your face. Discontinue use if you develop a rash, redness, or hives.
When it’s time for a full application, follow the instructions on the product’s label.
Vitamin C serum is typically applied once or twice per day. A good rule of thumb is to cleanse, tone, apply vitamin C serum, and then moisturize.
It can be safely used with other active ingredients, although using alongside niacinamide may make vitamin C less effective.
According to a 2020 reviewTrusted Source, a combination of tyrosine, zinc, and vitamin C was shown to increase the bioavailability of vitamin C 20 times than just vitamin C alone.
Potential side effects and risks
Although irritation is unlikely, you should always do a patch test before full application. This is the only way to determine how your skin will react to the serum.
If your skin is especially sensitive, avoid products with L-ascorbic acid. Products with magnesium ascorbyl phosphate may be less likely to cause irritation.