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Whether you’ve been looking to simplify your skin care routine or amp it up, a vitamin C serum might be your golden ticket. Topical vitamin C is a multipurpose workhorse that can protect, repair, and enhance your skin.

Not all serums are created equal. The type and concentration of vitamins C, the ingredient list, and even the kind of bottle or dispensers make or break your skin care regimen.

decoding which serum is not that hard. We have the facts on C serum benefits, how to choose one, and tips on how to use them.

A graphic of the best ways to apply vitamin C

Vitamin C is an antioxidant, meaning it halts or holds off environmental and sun damage to cells. And while you can count your morning OJ as a good defense for your bod, the best way to achieve vitamin C’s protection and benefits is to apply it directly onto your skin.

But there’s also a reason why you don’t want to just be placing citrus slices on your cheeks. When you DIY, there’s no control over the quality — and sometimes it’s not even safe. It’s also just not efficient.

That’s because when we eat, drink, or supplement vitamin C, also known as ascorbic acid, our skin only gets a small fraction of the benefits. However, pressing vitamin C in serum form, after it’s been chemically altered, actually lets our skin absorb more of it in an efficient way.

Vitamin C serum benefits

  • reduces wrinkling
  • It protects the collagen.
  • aids wound healing
  • It protects against sun damage.
  • hyperpigmentation is reduced.
  • Evens skin tone.
  • The complexion is bright.
  • acts like armor against pollution.

If you’re wondering when to apply a vitamin C serum, the answer is both morning and night, after cleansing and toning. One study even recommends applying a vitamin C serum every eight hours, or twice daily for the pinnacle of protection.

Vitamin C has photoprotective properties and staves off oxidative stress from the free radicals we meet throughout our day. Think car exhaust, cigarette smoke, certain chemicals, even booze and overprocessed foods.

“If you skip an application, don’t worry. Unlike sunscreens, oils, or moisturizers, vitamins C can’t be washed off easily.”

You can build up a photoprotection reservoir for adequate photo protection, even though it wears off the protection of the free radical-fighting prowess of thescorbic acid. This can be accomplished by applying for eight hours.

Also, UV light lowers the skin’s vitamin C levels. It’s been found that topical vitamin C is best applied after exposure to UV light and not prior.

Always use SPF with vitamin C

The sun sensitivity of the skin can be boosted by using both vitamins C and C.

A description of the best vitamin C serums

You might be ready to hit the buy button, but choosing a vitamin C serum that will actually go to work for your skin involves a bit of product research. We delved into the science and made some recommendations.

What to look for in a vitamin C serum

  • Form: L-ascorbic acid
  • Concentration: 10–20 percent
  • Ingredient combo: L-ascorbic acid, tocopherol (vitamin E) or glutathione, ferulic acid
  • Packaging: Dark or tinted glass bottles with airless delivery
  • Price: Not a factor in quality, but opt for the brand that fits your budget

Form: Vitamin C can appear on the ingredient label as several different names, but the one you want is L-ascorbic acid, which is the most effective. An older study comparing common vitamin C derivatives with L-ascorbic acid didn’t show an increase in absorption.

The good-guy ingredient should be at the top of the label.

Concentration: The sweet spot for the concentration level is between 10 and 20 percent. You definitely want a concentration that’s higher than 8 percent for maximum effectiveness. But going over 20 percent could lead to irritation and doesn’t increase its benefit.

Patch test with high percentages

In rare instances, side effects of vitamins C and E can be found, like stinging, redness, and a yellow color. Try a patch test first before you apply the full product.

Ingredient: Look for both vitamins C and E, or L-ascorbic acid and tocopherol respectively, on your ingredient list. Think of these skin boosters as besties that do well together.

Vitamin E stabilizes vitamin C for maximum skin protection. Another antioxidant called glutathione also is a good pal to vitamin C.

Then check for ferulic acid, which helps lower the pH level of vitamin C to below 3.5 percent so your skin can easily slurp up the cocktail.

Packaging: Exposure to air, light, and heat can degrade your serum. Look for a product that comes in a dark glass bottle featuring a medicine dropper delivery, rather than an air pump.

A tube works as well. Some retailers suggest storing products in the refrigerator. label instructions on how to store their serums will be included in a thoughtful brand.

Expiration time

If your product is brown or dark orange, it is time to toss it because it is gone bad. If your serum starts out clear and then turns yellow, that is a sign it is oxidizer and will be less effective.

Price: Factors like concentration and formulation determine a vitamin C serum’s quality, not the price tag. Prices run the gamut from $25 to more than $100.

L-ascorbic is one of the types of vitamins C that you want to look for in skin care. It is found in many vitamins C products. It is helpful for improving.

The name L-ascorbic refers to the chemical structure of the type of vitamins C and how it reacts to light. You may have heard of ascorbic acid, the form of vitamins C and E used in supplements. L-ascorbic is given a name based on how it rotates.

Synthetic and natural forms of the vitamins are broken down. Natural sources of L-ascorbic are found. It is found in fruits, vegetables, and human skin. The organic compound is found in the highest concentrations in the skin.

L-ascorbic is a trustworthy source of vitamins C and B. It is one of the most trusted active ingredients in skin care products. L-ascorbic is considered active and different from other forms of vitamins.

L-ascorbic can be put to use immediately since it is bioavailable. It can oxidize before it reaches your skin, so it can be unstable.

Other forms of vitamins C are inactive. They must be converted to L-ascorbic before they can be used on the skin.

“A higher percentage of L-ascorbic acid doesn’t always mean a better product. Sometimes it can be too strong for your skin, causing it to react. You don’t want the product to itch after you apply it.”

Serum Price and appeal Concentration/formulation
C E Ferulic by SkinCeuticals $166, serious skin care splurge and viral favorite for correcting oxidation Packs the perfect triple threat against damage: L-ascorbic acid (15%), plus vitamin E and ferulic acid.
Vitamin C, E + Ferulic Acid Serum by Marie Veronique $90, certified clean, cruelty free, and perfect for sensitive skin Blended with 5% ascorbic acid, 2% vitamin E, and 5% ferulic acid, this serum is perfect for sensitive skin. Applying twice a day will help you get the 10% your skin needs.
C-Firma Day Serum by Drunk Elephant $80, cult-status front-runner for exfoliating and hydrating benefits A perfect combo of enzymatic ingredients, hyaluronic acid, L-ascorbic acid (15%), vitamin E, and ferulic acid.
Mad Hippie Vitamin C Serum $33.99, GMO-free, vegan, natural, cruelty-free find Pretty much everything you could want: L-ascorbic acid, vitamin E, ferulic acid, hyaluronic acid, and konjac root for protection.
Revitalist Derm Intensives Vitamin C Face Serum by L’Oreal Paris $30, widely available favorite A lower concentration of L-ascorbic acid (10%) for folks prone to irritation. Plus, skin-smoothing silicone for immediate results and hydrating hyaluronic acid.
20% Vitamin C + E Ferulic Acid Serum by Timeless $26, budget-friendly powerhouse without essential oils Hydrates with a modified form of hyaluronic acid, plus features a trifecta of L-ascorbic acid (20%), vitamin E, and ferulic acid.
Beauty Shield Vitamin C Pollution Prevention Serum by e.l.f $16, drugstore grab and go The percentage is unknown, but for a drugstore product, the formulation of vitamin C, E, glycerin, and hyaluronic acid is primed for all skin types to apply freely.

Which vitamin C serums should you avoid?

If you have dry, dehydrated, sensitized, or sensitive skin, you may want to consider lighter vitamins C and C2 that have less than 20 percent L-ascorbic acid. If you like the higher end of the market, you should use a moisturizer with each use. Your skin only uses 10 percent of the benefits of the vitamin C, so you may not need full power with each application.

Is there too much skin Potion already? Adding a pinch of vitamins C and C2 to your existing regimen is possible.

You may have seen some skin care lines touting C powders, like Philosophy’s turbo booster version, which is nearly 100 percent ascorbic acid. Or you can snag a food-grade supplement powder, like NutriBiotic, at your favorite vitamin retailer for a fraction of the cost.

Pros of vitamin C powders Cons of vitamin C powders
inexpensive if purchasing as a supplement not as convenient (requires mixing)
adjustable (use less or more in your moisturizer or DIY serum) could cause irritation at high concentrations
longer shelf life in powder form may not stay as sanitary over time

The combination of vitamins C and E with other ingredients, like ferulic acid, help to keep it stable and allow it to be absorbed by your skin.

So, playing chemist in your bathroom with your own array of products may not produce the same results as buying a pre-crafted serum. However, if you’re a diehard DIY-er, you can use a powder to make your own affordable and serum with all the necessary ingredients.

“The bottom line is that if you buy a brand or form of it, you should be able to get the best results with your skin with lots of research. You don’t need a fancy version to get the skin-saving benefits of vitamins C and E.”

Some forms of the antioxidant can be unstable when combined with certain ingredients. Here are the ways to use your vitamins C and D correctly.

  1. Wash your face: Always start with clean skin so your vitamin C serum doesn’t mix with impurities.
  2. Use a toner or essence to balance skin’s pH: Avoid toners with other acids and exfoliants.
  3. Apply vitamin C to the face, neck, and chest: Look for a vitamin C serum that also contains vitamin E and ferulic acid, which can increase the stability and effectiveness of L-ascorbic.
  4. Moisturize to form a protective seal around skin: Avoid creams with retinol.
  5. Apply sunscreen. Vitamin C serums may increase skin’s sensitivity to sunlight.

Is L-ascorbic acid the same as vitamin C?

L-ascorbic acid is found in human skin. It is bioavailable and ready for immediate use, even though it is unstable.

Are there any side effects of using Vitamin C serums?

High concentration of vitamins can cause irritation. When mixed with active ingredients, such as Retinol, it can cause reactions. It can increase photosensitivity and sunscreen should be applied after using a vitamin C serum.

Should I use vitamin C serum in the morning or at night?

You can use the serum at any time of the day. It is common to use vitamins in the morning and retinol or exfoliants at night, but they should not be mixed in the same routine. If you go this route, make sure to use SPF when using vitamins C and D.

Should I use vitamin C serum before or after moisturizer?

You can use a face wash and a toner before applying your vitamins C and C.

The molecule size affects the order of your skin care products. A vitamins C and C is a good first choice because it has smaller molecule than a moisturizers. A moisturizer can seal in the vitamins.

People who use a vitamin C serum for their skin care routine will benefit. L-ascorbic, a highly researched active ingredient, has been shown to possess anti-aging properties. It is bio available and highly regarded in the cosmetic industry.

There are many benefits to using a vitamin C serum. The environmental stressors that the free radicals are fighting are pollution, sunlight, and harsh weather conditions. Pair a vitamin C serum with other vitamins and minerals to get the best results.

Jennifer Chesak is a medical journalist for several national publications, a writing instructor, and a freelance book editor. She earned her Master of Science in journalism from Northwestern’s Medill. She’s also the managing editor for the literary magazine, Shift. Jennifer lives in Nashville but hails from North Dakota, and when she’s not writing or sticking her nose in a book, she’s usually running trails or futzing with her garden. Follow her on Instagram or Twitter.