• Niacinamide and vitamin C are more popular than ever.
  • You can combine these vitamins for healthier and brighter skin—here’s how. 

For years, dermatologists have touted the benefits of antioxidants, which protect the skin from oxidative damage caused by free radicals. They also guard against environmental stressors such as pollution and UV radiation, which can break down collagen and lead to wrinkles and age spots. Thanks to a variety of benefits, two antioxidants in particular have gained enormous popularity amongst celebrities and influencers on social media platforms such as TikTok and Instagram: niacinamide and vitamin C.

“Consumers today are more ingredient-savvy than ever, and want skincare products backed by science that are effective without being irritating,” says Hallie McDonald, a board-certified dermatologist. “Niacinamide and vitamin C are powerful antioxidants that, with continued use, have the ability to improve the appearance of skin over time. Plus, today’s advanced product formulations make these ingredients easy to use and well-tolerated on skin.”

Ahead, top dermatologists give further insight into the powerful benefits of these two skin-protecting vitamins. 

What is Niacinamide?

Niacinamide is a form of vitamin B3 that plays a crucial role in maintaining healthy skin. “It’s incredibly multi-functional, yet gentle,” says Steve Xu, a board-certified dermatologist. “Niacinamide helps regulate oil production, strengthens the skin barrier, reduces inflammation, and improves the appearance of enlarged pores. It also has skin-brightening properties, which makes it great for evening [your] skin tone and fading hyperpigmentation. One of its most underrated benefits is its ability to enhance skin’s resilience, helping it better withstand environmental stressors like pollution and UV damage.

“I like to think of niacinamide as a skin optimizer. Whether you have acne-prone skin, sensitivity, dryness, or just want a smoother complexion, niacinamide fits in seamlessly. It’s one of those rare ingredients that works across skin types and concerns.”

What is Vitamin C?

Vitamin C is a powerhouse antioxidant and one of the most important skincare ingredients in terms of preventative care. “It can help stimulate collagen production to soften fine lines and wrinkles while supporting more glowy skin. Vitamin C also works to fade dark spots while protecting against free radicals such as environmental UV rays and pollution that can damage our skin,” says Roger Kapoor, a board-certified dermatologist.

“One of the biggest benefits of vitamin C is its role in brightening the complexion,” Dr. Xu notes. “It helps fade dark spots, post-acne marks, and uneven tone by interrupting the pathways that lead to excess melanin production. It also plays a key role in collagen synthesis, which is essential for maintaining firmness and reducing the appearance of fine lines over time. When someone asks me for a single ingredient that can do the heavy lifting in a morning routine, vitamin C is usually my first answer. It’s protective, corrective, and restorative all at once. It pairs incredibly well with sunscreen to boost the skin’s defense against sun damage and works across all skin tones and types.”

Vitamin C and niacinamide both have skin-brightening properties.

Getty Images

How They Differ

Niacinamide and vitamin C are both high-impact ingredients in skincare, but they work in different ways. “These two vitamins are distinct, yet complementary,” Dr. Kapoor says. “Niacinamide’s prime role is to strengthen the skin’s barrier and regulate oil production, making it excellent for people with sensitive skin or acne, while vitamin C works as a literal shield on our skin, bouncing back free radicals in the environment, usually from the sun or pollution. Because vitamin C works to inhibit an enzyme called ‘tyrosinase,’ it also has the ability to even out our skin tone by removing dark spots.” Thanks to its mild nature, niacinamide can be a great alternative for those with sensitive skin who may not tolerate vitamin C well but still want antioxidant protection and brightening benefits.

“They’re not mutually exclusive,” Dr. Xu. says. “In fact, they can complement each other well when formulated properly.”

When and How to Use Niacinamide and Vitamin C

Vitamin C should be applied in the morning to clean, dry skin to help protect it from environmental stressors throughout the day. Typically used on the face, it can also be beneficial on the neck, chest, and even the backs of the hands, where sun damage often shows first. “It’s especially effective in areas with uneven tone, dark spots, or signs of aging, and pairs well with sunscreen to boost antioxidant protection,” Dr. Xu says.

“Be sure to avoid applying vitamin C to broken skin or areas with active irritation,” Dr. McDonald cautions, “as it can cause stinging or discomfort.”

Niacinamide, typically applied as a serum or incorporated into a moisturizer, can be used both morning and night, typically after cleansing. “While it’s most often applied to the face, niacinamide is just as effective on the neck, chest, or even areas like the back and shoulders, especially if you’re dealing with breakouts or redness,” Dr. Xu says. “Because it’s gentle and versatile, niacinamide works well on all skin types.”

This ingredient-duo is especially great to use in the summer.

Getty Images

Can You Mix Niacinamide and Vitamin C?

Yes. In fact, many formulations come with them already combined. “Back in the day, it was thought that mixing them would cancel out their benefits, but that’s been debunked,” says Dr. Xu. “Modern formulations are stable and designed to be used together. When layered properly—vitamin C first, then niacinamide—they can brighten, protect, and calm the skin all at once, a powerful combination for anyone looking to improve tone, texture, and resilience without irritation.”

“Niacinamide can even reduce the irritation some people experience with vitamin C,” adds Dr. McDonald.

How to Layer

When it comes to layering, most dermatologists recommend applying a product with the lightest (most watery) consistency to the skin first, followed by the one with a heavier texture (such as creams and oils) in order to maximize absorption.

“Vitamin C and niacinamide are generally water-based and should be applied before a moisturizer or sunscreen,” says Dr. Kapoor. “A quick analogy would be: if it’s cold outside, you’d want to put the lightest piece of clothing on first, like a thermal shirt, before a sweater or coat,” says Dr. Kapoor. “I generally recommend two application options—either use them together and apply after cleansing and before moisturizing, or you use vitamin C in the morning to protect against environmental free radicals and the niacinamide at night to help restore your skin barrier.”

Ingredients to Avoid When Using Niacinamide and Vitamin C

When combining niacinamide and vitamin C, avoid layering on retinols, benzoyl peroxide, and strong acids. “A retinoid can cause irritation, benzoyl peroxide can inactivate vitamin C, and ingredients like glycolic, lactic, or salicylic acid can reduce their effectiveness,” shares Dr. Kapoor. Consider using niacinamide and vitamin C in the morning and one of these other actives in the evening.

Frequently Asked Questions

  • Which goes first, vitamin C or niacinamide?

    When layering niacinamide and vitamin C, apply vitamin C first.

    “Because L-ascorbic acid requires a low pH to be effective, applying it before other products ensures it can penetrate the skin properly without being neutralized,” Dr. McDonald says. “However, its low pH and sensitivity to light and air can also make it more irritating or unstable if not stored correctly. To preserve its potency, look for products in opaque, airtight packaging. Follow with niacinamide, which is more pH-flexible, then finish with a moisturizer and sunscreen.”

  • What ingredients should you not mix niacinamide with?

    Fortunately, niacinamide combines well with almost everything. “One caveat would be if you are using a high concentration of niacinamide, defined as anything above 10%. In this case, avoid mixing it with ingredients such as glycolic or salicylic acid, as the combination may result in skin irritation,” says Dr. Kapoor.

    “Niacinamide is generally very well-tolerated and plays nicely with most ingredients,” Dr. Xu says, “but if you’re using a very strong acidic vitamin C formula, it may cause irritation in some individuals when layered with niacinamide. Always patch-test if you’re introducing a new product, especially with more potent actives.”

  • What ingredients are best paired with niacinamide?

    Niacinamide on its own works well with most active ingredients like retinol, peptides, and hyaluronic acid, making it a versatile addition to any skin-care routine.

    “It plays especially well with hyaluronic acid to boost hydration and improve skin texture, and complements retinol by calming irritation while helping to minimize redness and inflammation,” says Dr. Xu. “Peptides are another great match, as they support skin repair and collagen production. And, of course, niacinamide works beautifully alongside vitamin C, providing a balanced approach to brightening and protecting the skin.”

  • Can you use vitamin C with niacinamide and hyaluronic acid?

    Absolutely. Combining vitamin C and niacinamide with hyaluronic acid is not only safe, but also highly effective for achieving a brighter, more even complexion. “Together, they create a powerful trio that addresses multiple skin concerns,” Dr. Xu says. “Vitamin C offers antioxidant protection and promotes collagen production, niacinamide helps to calm inflammation and improve skin texture, and hyaluronic acid provides deep hydration.”