First of all, vitamin C and niacinamide are both vitamins—niacinamide is also known as vitamin B3. They both help improve skin, and their differences work in complementary ways. 

“As an antioxidant, vitamin C helps to neutralize harmful free-radicals and environmental toxins that may come in contact with the skin,” says Imahiyerobo-Ip. “Vitamin C has photo-protective properties, which help to combat UV-induced skin damage. It also plays an important role in collagen synthesis and wound healing.” It can also help treat and prevent hyperpigmentation by decreasing melanin production.

Niacinamide, on the other hand, chiefly helps improve skin barrier function by keeping skin moisturized. “It does this by improving ceramide production and by preventing the evaporation of water from the skin into the environment,” says Imahiyerobo-Ip. Niacinamide also has anti-inflammatory properties, which can help soothe irritated or inflamed skin.” 

But that’s not all—niacinamide has some of the same properties as vitamin C. It also helps boost collagen production and stop melanin production, making it an anti-hyperpigmentation hero.