How does niacinamide work?

by Kate Lee

One of the most studied skincare ingredients for treating pigmentation, niacinamide is a popular antioxidant especially within the Asian beauty industry. But, what exactly is niacinamide and how does it deliver skin-brightening results? Can you use it with Vitamin C?


You've probably seen a bunch of products that claim to "whiten" or "lighten" skin. Many more products are spot treatments for acne and acne scars. These products aren't exactly bleaching agents, but rather something that helps to stop or decrease pigmentation. One of the more popular ingredients that's responsible for this is niacinamide. Niacinamide is the active form of vitamin B3, also called niacin (nicotinic acid). The niacinamide compound itself is found in many vegetables and in yeast, making it a wonderful plant-based ingredient for skincare aficionados who want more natural sources in the products they use.

How exactly does it lighten skin?

When your skin is exposed to any UV light, an enzyme called tyrosinase is activated. This is a key enzyme of melanogenesis, which is your skin darkening by producing melanin. Pigment producing cells are called melanocytes, and they contain little mebrane-lined vesicles, or pouches inside the cell, called melanosomes. The actual process of melanogenesis takes place inside melanosomes. One of the key components of pigmentation is the transfer of these melanosomes to keratinocytes, or cells that produce keratin. Still with me?

Niacinamide works by interrupting this transfer at the cellular level. One study found that niacinamide decreased melanosome transfer from melanocytes to keratinocytes by 35-68% in cell culture. It's important to remember that in vitro studies that have controlled culture environments are not always applicable to real life. In vivo studies that take into consideration the whole organism are often more reliable. A clinical study on niacinamide showed that topical use reduced hyperpigmentation and the look of fine lines and wrinkles. There are some fantastic options at all price ranges for niacinamide.

  • Paula's Choice Resist 10% Niacinamide Booster, $42
  • Holy Snails Shark Sauce, $29
  • Cosrx Galactomyces 95 Whitening Power Essence, $16.78
  • Missha First Treatment Essence Intensive, $49
  • Skin Inc. Vitamin B3+ Niacinamide Serum RESCUE TROUBLED SKIN, $35
  • The Ordinary Niacinamide 10% + Zinc 1%, $5.90

Vitamin C and Niacinamide

Now, for the debate about whether or not it negatively interacts with Vitamin C (ascorbic acid). If your Vitamin C is another ascorbic acid derivative, it still converts to ascorbic acid when it hits your skin and goes deeper. People tend to use Vitamin C and niacinamide together because both have a wonderful capacity to fight hyperpigmentation. However, many skincare websites will advise you not to use niacinamide with ascorbic acid. Why? First, niacin is formed whenever you mix niacinamide with an acid like Vitamin C (or a base). This process takes a long time but niacin also activates special Langerhans cells on your skin that dilate your blood vessels and cause your skin to flush and feel tingly. If you've got inflammatory acne or erythema, this is probably why you're cautioned not to combine ascorbic acid with niacinamide.

Second, niacinamide and ascorbic acid form a complex called niacinamide ascorbate. Studies have found that this complex is only formed well enough if the pH is just right (at 3.8), and at lower or higher pH, less of the complex is formed.

This is important. Our skin is acidic and as you get into the deeper layers of the skin, it becomes more and more basic (ha). So as the niacinamide and ascorbic acid get absorbed into the skin, there's less and less chance of them individually interacting with each other, and less chance for the niacinamide ascorbate complex to be associated with each other (aka, it could break apart because it's not at optimal pH). Cosmetic chemist, Stephen Ko, explains it best: the complex is held together like paper static, rather than glue. Some studies have shown that niacinamide ascorbate even helped to stabilize ascorbic acid, which is a very unstable compound.

Research has also shown that in the presence of UV light niacinamide and ascorbic acid form hydrogen peroxide. Not exactly the thing you want to have on your face. The study did show that the effect was small and the mechanism they proposed was theoretical. It's always important to not just know the end result, but the actual magnitude of it.

What do I do?

The key thing to take away is that niacinamide and ascorbic acid are wonderful ingredients for hyperpigmentation, and while they can form chemical reactions that could irritate some skin types, it's reversible and occurs very slowly. If you want to use them both, you could do one during the day and one at night, or just use both of them in the evenings if you're on the cautious side with UV exposure.