Can you use vitamin C and niacinamide together? We get asked this question a lot, so we asked a cosmetic chemist and a derm to answer it for you.
Sometimes the goal of brighter skin can seem almost unattainable, but thankfully there are ingredients like vitamin C and niacinamide which help to fade those dreaded acne scars and leave your skin glowing. We know a lot of you have been saavy enough to think of combining the two to double the effects, but you’re scared to actually do it because you’ve probably heard this rule before: “You can’t use vitamin C and niacinamide together.”
Is it true? To get the facts on this ingredient combo, we reached out to Joshua Zeichner, director of cosmetic and clinical research at Mount Sinai Hospital in New York City and Stephen Ko, Reddit’s famous cosmetic chemist. Keep reading to find out.
First, how do vitamin C and niacinamide benefit the skin?
Vitamin C, or pure ascorbic acid, is a naturally occurring antioxidant that helps to protect us from UV damage as well as reduce hyperpigmentation (from sun spots or acne scars) and even increase collagen production. On the other hand, niacinamide is a form of vitamin B3 that helps to do everything from improve your skin’s barrier function to fade acne scars and even help reduce and regulate sebum production. Plus, niacinamide helps to smooth out fine lines and wrinkles!
These two superstar ingredients are well known for their benefits, so it would make sense that you would want to use them together, especially to maximize their brightening capabilities.
Can they work together?
There is a fear of using vitamin C and niacinamide together because it’s believed that they’ll cancel each other out, rendering both formulas ineffective. This fear is only increased by the fact that vitamin C is an extremely finicky ingredient to work with, making it super important that it’s formulated correctly.
To rest your fears at least a little bit, most articles that claim that niacinamide and vitamin C can’t work together reference studies from over 40 years ago, meaning a lot more research has been done since then. Plus, Zeichner also suggests that it’s completely fine to “layer your niacinamide-containing product along with your vitamin C serum” since the “ingredients complement each other by improving skin radiance and evening skin tone and texture.”
A lot of the concern stems from the idea of niacinamide hydrolyzing into nicotinic acid (AKA niacin) when combined with vitamin C or any other acidic product. This conversion activates epidermal langerhans cells, causing facial flushing, AKA redness and tingling. But any product with niacinamide and an acid can actually hydrolyze into nicotinic acid over time, regardless of its association with vitamin C.
It’s important to remember that niacinamide is actually an incredibly tough ingredient—heat and other environmental factors don’t have as much of an impact on it as they would on more delicate ingredients. Additionally, studies on niacinamide’s conversion to nicotinic acid show that it only converts under extreme heat for extended periods of time, and that only small amounts of the product actually change over. This conversion can easily be reduced by keeping your product with niacinamide out of direct sunlight and in a cooler, more stable environment.
Cosmetic chemist Stephen Ko explains, “While the combination of niacinamide and ascorbic acid in certain conditions can form niacin, it takes a lot of time or heat. When you’re just layering products the amount formed is likely minimal. Niacin is undesirable because it can cause really bad flushing, which you shouldn’t confuse with simple irritation. Flushing is quite persistent and rash like, though temporary. So unless you’re seeing flushing, you’re likely fine with the combination.”
The other issue is that when vitamin C and niacinamide are combined they turn into a yellow liquid, leading most people to believe this causes a negative reaction making both products ineffective. I’ve even seen some claims saying that the vitamin C instantaneously oxidizes and you cannot use it anymore. But these fears are unjustified because the yellow combination is actually a result of a charge-transfer interaction that converts the niacinamide and ascorbic acid into niacinamide ascorbate. Rest assured, this combo is safe to use and still works to brighten the skin.
It’s perfectly fine to use niacinamide and vitamin C together. The worries of rendering them both ineffective are just caused by misinformation and lack of research. When it comes down to it, it’s all about personal preference. If you have more sensitive skin and are worried about the possible effects of a niacin flush, then you can alternate your niacinamide and vitamin C day to day. But if your skin isn’t particularly sensitive, go ahead and use them together!
One of my favorite combinations is the CosRX Triple C Lightning Liquid (reach for the Klairs Freshly Juiced Vitamin C Serum if you have super sensitive skin) with the niacinamide-rich ENature Brightening Emulsion. Plus, keep in mind that there are plenty of other items on the market that use niacinamide and vitamin C in one product.