Alicia Yoon is a Korean skincare expert and the founder of Peach & Lily, a leading source and retailer for all things Korean beauty.
Vitamin C is one of the most celebrated—and misunderstood—skincare ingredients. At Peach & Lily, our licensed estheticians receive many skincare questions, and many of them are about vitamin C. On our brand's Instagram page, I also receive many direct messages from our community about vitamin C products. And as an esthetician, I often field questions from clients during skincare consultations and facials about the buzzy ingredient. There are a lot of myths about vitamin C that have been perpetuated, so I'm setting the record straight by breaking down the most commonly asked questions and misunderstood elements about the ingredient. Keep scrolling for everything you need to know.
Myth #1: Vitamin C is all the same.
The front of your vitamin C product may read as just simply containing vitamin C. But when you read the ingredient list, it can show up as L-Ascorbic Acid (pure vitamin C) or a different name such as ascorbyl glucoside, magnesium ascorbyl phosphate, ascorbyl tetraisopalmitate, etc. These are ingredients derived from vitamin C, but contain additives to either make the ingredient more stable or more easily absorbable. Here’s the catch though: each kind of vitamin C has different nuances and the impact on your skin—both from an irritation perspective and an efficacy perspective—can vary widely.
So, if you’ve tried a vitamin C product, and you felt that it didn’t do much for you or caused irritation, see exactly what kind of Vitamin C was used, what percentage, and what pH level the overall formula was. That will give you an idea of what your skin didn’t like, and you can move onto exploring other kinds of vitamin C’s. If you want a surefire shot of selecting a vitamin C product that isn’t going to oxidize as easily and is less likely to cause irritation, opt for a stabilized derivative that doesn’t need to be in a low pH formula, like ascorbyl tetraisopalmitate.
Myth #2: Vitamin C can cause sun sensitivity.
Vitamin C in its pure form is acidic, which may be why many people believe Vitamin C should be used in the evening only. But unlike some other acids, vitamin C is not shown to increase sensitivity to the sun. In fact, studies show that this powerful antioxidant can actually help protect against free radical damage from the sun. This doesn’t mean it’s time to skimp on your SPF, but pairing vitamin C with your SPF can be a great idea.
This also means you can choose to apply your vitamin C product in the a.m. or p.m. (or both), depending on what benefits you’re seeking and how it feels in your routine. For example, if you’re looking for antioxidative benefits during the daytime, apply in the morning. If you’re focused on firming and rejuvenating skin (as vitamin C is shown to boost collagen production), incorporating it into your evening routine could be great. Separately, vitamin C products come in all different textures—silky, tacky, creamy, and oily. If you’re loving your vitamin C product but find certain textures more enjoyable in either your morning or nighttime routine, go for the time of the day you prefer applying it because consistency matters.
Myth #3: Vitamin C is only for certain skin types—and definitely not for sensitive skin.
Our bodies cannot make our own vitamin C, so the only way to benefit from vitamin C is through what we eat or apply topically. The good news is that vitamin C can be suitable for all skin types. The trick is to find the right type of vitamin C for you. For example, L-ascorbic acid needs to be formulated in lower pH levels than most derivatives. So while it’s one of the most potent versions in the world of vitamin C (as long as it doesn’t oxidize), it’s also one of the more irritating in the vitamin C world.
If you have sensitive skin, opt for a derivative that comes in a less acidic formula. If you want to see results quickly, opt for a derivative that has more robust clinical studies on the concerns you’re targeting. THD ascorbate and ascorbyl tetraisopalmitate—two similar types of Vitamin C derivatives—are both lipid-soluble, so they are known to absorb better into the skin for visible results. Ascorbyl tetraisopalmitate has bendier “arms” on the molecule as compared to THD ascorbate for potentially even better absorption. Bottom line: if you want to use a vitamin C product, don’t assume that your skin type excludes you from finding one that works for you. You can find a vitamin C product that fits on our website.
Myth #4: The more vitamin C, the better.
A formula that contains a high percentage of vitamin C, but isn’t properly formulated to stay stable and effective can be far less impressive than a vitamin C formula with a smaller concentration. Additionally, absorbability matters too. If a derivative is known to absorb better, a smaller concentration can deliver more visible results than a formula that boasts a larger percentage but delivers less penetration into the skin. Too much vitamin C can also be irritating depending on the derivative, so higher doesn’t always mean better skin results.
So, how do you navigate what concentration is right for you? Always start with the back of the box. Identify the vitamin C that is being used. Then, research that specific type to see how well it absorbs. Based on that, you can see what concentration you prefer. If you want to dig even deeper, you can also ask the brand for more information and even studies on the vitamin C they use. Not all brands may readily provide this data, but many will do so to maintain consumer transparency. Bottom line: don’t rely solely on the percentage on the bottle. Consider the type of vitamin C used and when in doubt, don’t be afraid to ask for more information.
Myth #5: Vitamin C will stain or tan the skin.
You might have noticed that after using some of your vitamin C products, your hands and face may turn a bit orange as though you just applied a tanning product. Well, you’re not imagining things here. L-ascorbic acid slowly degrades to a sugar that works like fake tanners. The result will be temporary like a fake tan. If you’re an L-ascorbic acid fan, there are a few tips to keep in mind. Use your vitamin C formula before it degrades (it’ll be more potent anyway), so apply it consistently in a frequency right for your skin. You should also wash your hands right after applying. It's also important to evenly apply the product all over your face so there aren't uneven splotches. The last method to implement into your routine is to try applying oil over your vitamin C product so that it helps prevent on-skin oxidation. You can also opt for a more stable derivative that won’t cause temporary tanning-like effects.
Myth #6: You can grow resistant to Vitamin C.
We get a lot of questions about tolerance and resistance to ingredients. The way one builds resistance is when the number of receptors decreases or becomes less sensitive to the ingredient. Studies don’t show this happening with vitamin C, and research has also not indicated that there are specific receptors involved in how vitamin C is utilized by our skin. I like to think of vitamin C as similar to eating nourishing foods each day. Even though I’m doing this on a daily basis, my body isn’t growing resistant to the vegetables I’m eating. Your skin evolves, and its needs do change, so you may be refreshing your skincare routine seasonally and over time, but it isn’t because your skin became "used to" your vitamin C product. So fear not; if you find a great vitamin C formula that’s working for you, you don’t need to worry about it "wearing-off" one day. You can use it as frequently as is right for your skin and do so worry-free.
Myth #7: Vitamin C can’t be combined with other acids, retinol, or niacinamide.
Let’s start with vitamin C and niacinamide. This myth comes from an outdated study that shows the two can potentially react to form nicotinic acid, which can cause irritation. However, this potential exists only when pure ascorbic acid and niacinamide are combined at very high temperatures, which is not the case for our skincare application. In fact, pairing these two ingredients can be a winning combination, especially for tackling hyperpigmentation because the two work in different ways to combat discoloration. Vitamin C is shown to inhibit the actual over-production of the pigmentation and niacinamide is shown to help prevent the transfer of the overproduced pigmentation within cells. I’ve been recently struggling more with hyperpigmentation and combining a soon-to-come vitamin C formula with our cult-favorite Glass Skin Refining Serum (which contains 2% niacinamide) has been a powerhouse combination.
Now when it comes to vitamin C and AHAs, BHAs, and retinol, there’s a lot of confusion, especially since some vitamin C formulas are pH-dependent. Questions often arise like, "Would a higher pH AHA or BHA or retinol reduce the efficacy? and "Do these actives cancel out the benefits of vitamin C?" The short answer is no. Vitamin C can be used with acids and retinol. However, the biggest risk is irritation to the skin. For most people, this potent cocktail can be too much for the skin. And in my opinion, too many actives are far worse than no actives. Extreme irritation can lead to a lot of damage and it can take a while before the skin becomes less reactive and finds its balance again. My recommendation with actives—including vitamin C—is to slowly work your way up. For a lot of people, “working your way up” means never really having to mix actives altogether in one routine. Spread out your actives between your morning and night routine or even between days or weeks. See what feels right for your skin and patch test. If you see signs of irritation, even slight, it’s a good idea to scale back before the irritation worsens.
Peach & Lily's new 20% Vitamin C spot treatment rapidly targets dark spots, hyperpigmentation, and scarring to leave them looking brighter and even. The innovative formula, which took three years to perfect, is suitable to use on all skin types.
Skinceuticals C E Ferulic is a tried-and-true highly potent ascorbic acid formula. It is designed to provide environmental protection, lightens lines, firm skin, and brighten your complexion.
The Biossance Squalane + Vitamin C Oil is an oil-based vitamin C formula that uses THD ascorbate. With continued use, you'll notice visibly brighter and firmer skin.
This budget-friendly pick is a sodium ascorbyl phosphate-based vitamin C serum. The plant-based facial product effectively promotes your skin's response to signs of aging by boosting brightness and diminishing wrinkles and dark spots.
If you have sensitive skin, try this serum from isClinical. Its gentle blend of vitamin C and botanicals helps to treat acne, rosacea, contact dermatitis, and insect bites.