Updated 06/08/21. Using a daily vitamin C serum is one of the best ways to slow down the progression of visible signs of aging and fade brown spots. However, using a daily vitamin C serum can be tricky when you also exfoliate and/or use retinol regularly. This is because the regular use of retinol, retinoids, and exfoliating acids can affect the skin barrier, causing it to become fragile, which can make the skin feel sensitive. (That’s why you must be careful when it comes to these ingredients. The last thing you want is for a product to work against you, causing issues rather than solving them.)
The good news is that you can, in fact, use a vitamin C serum alongside retinol and acids without causing irritation to sensitive skin. You just have to know what to look for in a product. Keep reading to learn the five qualities of a good vitamin C serum—these are important all the time, but especially when you’re using retinol or exfoliating acids.
Five Things to Look For in a Vitamin C Serum
1. It Shouldn’t Cause Dryness, Redness, or Irritation
If you’re currently applying vitamin C daily, and you’re experiencing dryness (which is also known as a damaged moisture barrier), don’t think it’s solely due to your use of retinol, retinoids, or exfoliating acids—it might actually be due to the vitamin C serum itself. Here’s why—when a serum contains pure ascorbic acid (which is considered an unstable form of vitamin C), it be irritating, since it’s an acid with a low pH. This causes an acidic effect on the skin, which can lead to increased sensitivity. Vitamin C shouldn’t cause redness, dryness, or inflammation, so it’s best to avoid formulas in which the bulk of the vitamin C comes from ascorbic acid or L-ascorbic acid.
If you’re someone who has sensitive skin, you’re much better off choosing a vitamin C serum with ingredients that are known for being stable and less acidic on the skin. Vitamin C derivatives are the best forms of vitamin C that won’t irritate the skin and will still be effective. Examples include tetrahexyldecyl ascorbate, ascorbyl methylsilanol pectinate, ascorbyl palmitate, and sodium ascorbyl phosphate. These non-acidic forms do a better job of maintaining stability and performance. That’s why I chose to formulate the Vitamin C&E Treatment with tetrahexyldecyl ascorbate and ascorbyl methylsilanol pectinate. Both of these ingredients are stable forms of vitamin C that can increase skin brightness and provide powerful antioxidant benefits.
2. It Should Make Blackheads Better—Not Worse
Ascorbic and L-ascorbic acids are known to oxidize quickly in the presence of light and air, which can use unwanted side effects, such as more noticeable blackheads! Let me explain. The reason blackheads appear in the first place is due to enlarged pores with hardened oil stuck inside. The oil oxidizes on the surface and turns dark gray in color (not technically black). If you’re using a daily vitamin C serum that oxidizes quickly, it can make the blackhead become even darker, making them more noticeable. No one wants that! As a hands-on esthetician for over 30 years, I can see a huge improvement in my clients’ blackheads when they switch to a stable, non-oxidizing vitamin C formula. (On that note: read my three-step plan for reducing blackheads).
3. It Shouldn’t Change Color Over Time.
When a vitamin C serum turns a copper-brown color, it’s a sign that it’s formulated with an unstable form of vitamin C (such as the aforementioned ascorbic acid). This type of vitamin C allows for oxidation to occur rapidly, which causes the formula to lose efficacy. Once the product has started to turn a light brown or copper color, you’re definitely NOT getting the full benefit from it. Manufacturers of such formulas can’t disagree; these companies will attempt to slow this process down by packing their formulas in amber-colored bottles instead of clear ones. However, it can’t be prevented entirely, and they know this. As a result, some companies even get a little sneaky by changing the formula from clear to brown with synthetic dye. The hope is that the drastic change in color will be less noticeable to the consumer.
If you’re currently using a vitamin C serum that discolors over time, it’s time to consider other formulas. You’re simply not getting the biggest bang for your buck, as the product will lose much of its efficacy before you’ve finished it. Simply look at the ingredient list. Ascorbic and L-ascorbic acids are notorious for their instability. This type of vitamin C should be avoided, especially if you use retinol or exfoliating acids.
You might be asking yourself, why do companies still use these types of vitamin C if they don’t hold up well? I believe that many companies have an “if it’s not broke, don’t fix it” mentality. Sure, when it comes from a freshly opened bottle, these types of vitamin C will definitely do the job. However, they miss the mark when they don’t take into consideration how the skin habits of consumers have evolved over the years. Now more than ever before, people are using products with active ingredients like retinol, retinoids, and exfoliating acids and because of this, their skin barriers are being compromised. As a result, skin sensitivity is at an all-time high. Therefore, retinol users should avoid unstable types of Vitamin C.
4. It Should Contain a Variety of Other Active Ingredients to Further Protect the Skin
Antioxidant-based products like vitamin C serums are meant to be used during the day underneath sunscreen to protect your skin from harmful free radicals. The three types of free radicals are reactive oxygen species, reactive carbonyl species, and reactive nitrogen species. Collectively, these free radicals cause destruction by changing your skin cells, causing them to age faster (aging can be boiled down to two words: changed cells). You’ll want to look for a formula that contains a variety of skin-protecting ingredients, like vitamin E and green tea extract. A good rule of thumb to find additional skin-protecting actives is to look at the key ingredients that are being promoted in the product.
5. It Should Come in Opaque, Airless Packaging
Air and light are vitamin C’s worst enemies. So, packaging that allows air and light to make easy contact with the formula is a big mistake, and cosmetic formulators know this. When choosing a vitamin C serum, avoid those in which you can see the formula through the container (this means light is able to penetrate the packaging). Also, be sure to avoid those that use a dropper bottle or dip tube pump to dispense the product (this means that air can easily enter).
Packaging is important when it comes to all serums, even those that are without vitamin C. Look for what is known as airless packaging. This is the type that industry experts recommend. Note: for this type of packaging, you can’t see when the product is getting low, which makes it difficult to know when you need to repurchase it. There’s an easy solution for this. Simply unscrew the pump and dip a cotton swab inside to measure how much product is left. Don’t worry about a little air getting in because once you close it up and go to pump it again, any air will pump right out. This is the magic of airless packaging!
Vitamin C for Retinol Users Must Be Chosen Carefully
To summarize, it’s important to choose a formula that offers long-lasting activity in the skin with maximum stability. A product that relies exclusively on ascorbic or L-ascorbic acids will not deliver the full benefits of vitamin C if the formula can’t hold up. What’s worse is that it can actually cause unnecessary irritation to anyone who has a weakened skin barrier.
Vitamin C can be used safely and effectively, even if you regularly use retinol and/or exfoliating acids. Follow these rules when choosing a vitamin C product, and you’ll be well on your way to reaping the maximum anti-aging and brightening benefits of this skincare ingredient.
Celebrity Esthetician & Skincare Expert
As an esthetician trained in cosmetic chemistry, Renée Rouleau has spent 30 years researching skin, educating her audience, and building an award-winning line of products. Trusted by celebrities, editors, bloggers, and skincare obsessives around the globe, her vast real-world knowledge and constant research are why Marie Claire calls her “the most passionate skin practitioner we know.”