What are the benefits of niacinamide for the face?

It has been demonstrated that topical niacinamide has the ability to increase the levels of intracellular NAD and NADP cofactors, which decrease with age, and whose reduced forms (NADH and NADPH) possess antioxidant properties. Thus, it helps to limit the action of free radicals by trapping the oxidizing radical and protecting the skin from damage directly to DNA, lipids, and proteins caused by factors such as natural aging, UV rays from the sun, pollution, or stress. Some research has also shown that topical niacinamide reduces the appearance of wrinkles and fine lines. It is believed to have the ability to stimulate the production of collagen in the dermal matrix and proteins in the epidermis, such as keratin, filaggrin, and involucrin.

Several reports suggest that skincare formulas containing 5% niacinamide may also affect pigmentation and help to fade hyperpigmented spots. The benefits were observed after twelve weeks of use. It has shown to reversibly block the transfer of melanosomes from melanocytes to surrounding keratinocytes by inhibiting keratinocyte factors, distinguishing it from other brightening actives that have a direct action on tyrosinase activity. Indeed, an in vitro study showed that daily use of a moisturizer with 5% niacinamide inhibits 35 to 68% of the transfer of melanosomes from melanocytes to keratinocytes. By preventing the transfer of melanin into the skin, niacinamide thus helps to eliminate hyperpigmentation and even out skin tone.

The glycation of proteins (collagen, elastin) with sugar leads to the formation of cross-linked products of a yellowish-brown color (Amadori products), which accumulate in the components of the skin matrix. These oxidation products are responsible for the dull complexion observed on damaged skin. Thanks to its antioxidant capabilities as a precursor of the coenzymes NADP and NAD, niacinamide inhibits these oxidative processes. It can thus help to improve the appearance of photo-damaged and photo-aged skin.

While sebum can fulfill important functions (providing antioxidants, regulating transepidermal water loss, etc.), the presence of this sebum layer that covers the surface of the facial skin is considered unsightly and undesirable. It contributes to facial shine, and gives the skin a greasy appearance. However, the niacinamide applied topically has proven effective in reducing sebum production by the sebaceous glands, which can prevent skin breakouts and clogged pores. Its mechanism of action has not yet been fully elucidated.

Topical niacinamide is also believed to have bacteriostatic effects on Propionibacterium acnes, which could be explained by its action on the Sir2 enzyme. In addition to its anti-inflammatory and sebostatic role, topical nicotinamide could thus have an anti-acne effect. Indeed, clinical trials on patients with moderate acne have reported that topical use of niacinamide has led to a regression of inflammatory lesions after eight weeks of treatment.

The over-activation of PARP-1, an enzyme, by UV rays involved in cellular senescence, aging, and cancer, leads to a depletion of cellular NAD, which slows down the DNA repair process. However, nicotinamide replenishes cellular energy, as it is a precursor of NAD and NADP. Moreover, it has an inhibitory effect on PARP-1 through negative feedback, thus preventing cellular senescence. Lastly, nicotinamide also protects against UVA and UVB-induced immunosuppression. Therefore, nicotinamide could protect and mitigate the mutagenic and immunosuppressive effects of UV light on the skin, beneficial in the prevention of skin cancer.

Nothing has been proven to reduce pore size, but niacinamide can help minimize their appearance. It's important to know that sebum is associated with the enlargement of pores. However, it appears that niacinamide has the ability to normalize sebum secretion and this effect plays a role in preventing pore congestion and therefore its dilation.