When was the last time you took a thorough look at the labels on the products in your skincare routine? Are you using too much of any one ingredient? You might be surprised to find out that you probably are. With the rise of individual ingredient serums that allow users to create a cocktail that targets their unique issues and concerns, many beauty consumers are adopting the role of chemist in their bathrooms each morning and evening. But that may not always be a good thing, especially when it comes to three beloved “hero” ingredients that are popping up everywhere: niacinamide, hyaluronic acid and vitamin C.
Yes, these ingredients can work wonders—but they can also irritate your skin if you overdo it. And considering their rise in popularity, they are probably already in some of your other products—like your cleaner and moisturizer—so you probably don’t need to be adding additional concentrates.
Here’s what to know about these three popular skincare ingredients—and when to limit your use.
Niacinamide
According to a report by Spate, a consumer data organization that analyzes trends in the food and beauty industries, searches for niacinamide serums have spiked a staggering 193% since the end of July. What gives? “Given the pandemic, consumers spend more time looking for ways to take care of their skin, hence the significant increase in searches for ingredients that are known to improve skin [function],” says cosmetic chemist Ron Robinson of BeautyStat.com.
What does niacinamide do?
Niacinamide is a water-soluble form of vitamin B3 that boasts a wide array of skin benefits. Loaded with antioxidant and anti-inflammatory properties, it can increase natural lipids that are found on the skin’s surface, strengthening skin’s protective barrier (and thus reducing moisture loss) and reduce both unwanted pigmentation as well as redness caused by inflammation.
Read this next: Let’s Get to the Bottom of the “Right” Way to Apply Your Skincare
Is niacinamide safe?
As far as active ingredients go, niacinamide is generally very safe (and calming, actually). But according to this thread on the AsianBeauty subreddit, niacinamide sensitivities—while rare—do exist. More commonly, though, if you think you’re experiencing a reaction to niacinamide, you may just be using too high of a percentage for your skin type, so start by looking at the ingredient’s percentage in the formulation you’re using.
What percentage of niacinamide should you be using?
Most dermatologists and cosmetic chemists recommend staying within the 2–5% range. Neostrata’s Illuminating Serum, for instance, features 4% niacinamide, which will be well-tolerated by most skin types.
Using a product with, say, 10% niacinamide won’t cause any major issues, but you may experience some irritation and redness, especially because niacinamide is quite easily absorbed into skin. In fact, a 2013 study found that “high levels of niacinamide can increase serum histamine levels, which may cause an allergic reaction for people prone to skin allergies.”
In a post on her site Lab Muffin, science educator Michelle Wong looked into a recently launched powder version of niacinamide that is formulated with 100% (!!!) niacinamide. To date, the Cosmetic Ingredient Review’s Safety Assessment of niacinamide has only tested the ingredient at up to 20% for irritancy potential. So at best, using a niacinamide product that’s that potent may just not be necessary or useful. At worst, it might really cause your skin to freak out. The takeaway here: “There’s no reliable evidence that higher percentages work better,” writes Wong.
Hyaluronic acid
Talk of hyaluronic acid is everywhere. And while its popularity is justified (it is, after all, a highly effective ingredient that does what it promises to do), many people misunderstand how to best use it. For example, hyaluronic acid is often referred to as a hydrator, but that’s not exactly correct. It’s more of a plumper. In this piece for Harper’s Bazaar, beauty reporter Jessica DeFino writes that this misunderstanding is causing people to misuse hyaluronic acid—i.e. they are using too much of it, causing the ingredient (which is famous for its ability to pull in water) to “[slurp] up the moisture that sits within your skin.”
Read this next: PSA: Stop Using Coconut Oil As a Moisturizer! Plus 4 Other Skincare Myths, Busted
What does hyaluronic acid do?
Hyaluronic acid, which is naturally found in our skin and is also the star ingredient in injectable fillers, is loved for its ability to instantly plump skin, fill fine lines and, of course, hold up to 1,000 times its weight in water.
When it’s pulling in water from your external environment, that’s a (very) good thing. But as DeFino warns, using it on its own (and in too high of a concentration) will only “temporarily make the skin appear hydrated and smooth.” Once that moisture—which it took from your own skin—evaporates? Well, the plumping effect disappears with it.
Is hyaluronic acid safe?
Generally, yes. But as Dr. Shereene Idriss, a board-certified dermatologist at Union Square Laser Dermatology explains in this article on The Cut, “Studies are correlating topical application of low-molecular-weight HA (the type needed to penetrate the surface of your skin barrier) with inflammatory reactions.” Chilling, right?
A close look at the ingredient lists on your products may reveal hyaluronic acid’s presence throughout your regimen—in your cleanser, your moisturizer, your eye cream, your night cream and your masks. And if you also use a separate, concentrated hyaluronic acid serum on top of (or technically, it’d be underneath) all of that? You could be setting yourself up for some pretty unhappy skin.
What percentage of hyaluronic acid should you be using?
Anywhere from 1–2% is effective, so there’s no need to be using formulas that boast higher. “Some HA formulations have high percentages that can potentially dehydrate the skin unless combined with a more emollient ingredient to lock in hydration,” says celebrity dermatologist Dr. Dendy Engelman. So if you’re experiencing irritation, dryness or redness, a good first step would be to stop cocktailing individual ingredients. Irritation is more likely to occur when it comes to pure HA serums that aren’t formulated with other ingredients to lock in moisture.
Enter: Elizabeth Arden’s new Hyaluronic Acid Ceramide Capsules Hydra-Plumping Serum. Because of the addition of ceramides, you’re also getting barrier protection that seals moisture in. So when the water that the HA is hanging on to tries to evaporate, it can’t escape.
Read this next: Should You Switch Up Your Skincare Routine When You’re on Your Period?
Vitamin C
This brings us to vitamin C, or L-ascorbic acid (the chemically active—and most researched—form of vitamin C that’s usually found in skincare ingredients). This one is particularly tricky, because it can be pretty unstable. In a post on Lab Muffin, Wong writes that “Vitamin C in the form of ascorbic acid oxidizes easily to dehydroascorbic acid, which has an orange-brown colour. It does this when it’s stored in water, as well as on your skin. Oxygen and light exposure will speed up the oxidation reaction.” Using a product that’s oxidized is still safe (though it may actually stain your skin a bit), but it won’t be as effective at evening your skin tone, brightening your complexion, and all of the other stuff you want a vitamin C serum to do.
What does vitamin C do?
The antioxidant ingredient boasts plenty of benefits, from brightening to boosting collagen production to evening out skin tone and treating discolouration. Unfortunately, it can also be kind of irritating for ultra-sensitive skin types.
Is vitamin C safe?
The best way to determine if your skin can tolerate vitamin C is to patch test. Apply a small amount of your vitamin C product to your arm (or leg or stomach—just not your face) and wait 24 hours. If you don’t notice an allergic reaction, you’re ready to incorporate it into your routine.
What percentage of vitamin C should you be using?
Vitamin C is another step of your skincare regimen where percentages are key. The optimal percentage for L-ascorbic acid in a formulation is 10–20%. Less than that and you’re probably not getting the benefits of the ingredient, and more than 20% is, well, a waste. Our skin can’t really absorb any more than that (as this study notes, “the efficacy of Vitamin C serum is proportional to the concentration, but only up to 20%”), so even if you don’t suffer any redness or irritation, you’ll be irritating your wallet—especially considering that vitamin C serums tend to be on the pricier side.
This study on vitamin C notes that “the half-life [of L-ascorbic acid] in the skin after achieving maximum concentration is four days.” In other words, your skin essentially has a reservoir of L-ascorbic acid that remains active even days after application, so there’s no need to load up on multiple products that contain vitamin C. There really is only so much your skin can absorb, and if you’ve opted for a stable, clinically tested L-ascorbic acid at an appropriate concentration (like BeautyStat’s beloved Vitamin C Skin Refiner), that’s all you really need.
The bottom line
While there certainly can be benefits taking a DIY approach to cocktailing the ingredients in your skincare routine (Customization! Affordability! Accessibility!), it’s not the best idea for beginners or for the faint of heart (and skin), because of the many risks involved.
Remember, cosmetic chemists and formulators work to make products you can trust to be safe and effective, and their knowledge and vast expertise can’t—and shouldn’t—be pushed aside for the sake of a personalized skin experiment. This is especially true if you’re new to the world of active ingredients or have sensitive skin.
“It’s about quality, over quantity,” explains Dr. Engelman. “There are a few things that can go wrong when using too many skincare products. Some ingredients cancel out the effects of others, or can be irritating to the skin, causing dryness or sensitivity. This, of course, is the opposite of what you’re trying to achieve with your regimen. Many patients have really leaned into active ingredients, buying individual actives and applying them all at once,” says Dr. Engelman. “I don’t advise this approach. Patients will come to me red and irritated because they’ve stripped their skin playing home alchemist.”
In fact, Dr. Engelman says that we’re probably using way too many products in general: “I like multi-purpose products. There is no need to have 15 steps in your skincare routine when many products exist to target various skin concerns at once.”
Read this next: The Best Face Cleansers for Every Skin Type
The best thing to do? Pick one or two areas to target and limit your products to those that will address them. “Make a skincare goal so you can put together a defined plan,” says Neostrata Canada National Trainer Patricia Clare. “It’s like having a fitness goal. If a trainer asks you what you want to do and you say ‘get fit,’ that’s a very broad term. Is it endurance you want? Is it a [more toned] body? Don’t be vague. When you get more precise with a skincare plan, it helps you to pick ingredients.”
Once you’ve determined a goal or two for the time being (say, improving hydration and getting rid of some dark spots, rather than trying to address 10 different issues with 10 different serums), your best bet is to opt for products that have been clinically tested and proven to work, and are formulated with ingredients that enhance their efficacy and your usage experience—rather than trying single-ingredient serums. “This is the safest and most effective way for the average consumer to incorporate new products into their daily skincare routine,” says Dr. Engelman. “These products are already calculated with the right active ingredient ratio.” So, leave the skincare math to the pros.