Niacinamide: The Ultimate Skincare Ingredient

 by Alice Ren

Skincare has grown increasingly popular in recent months, among both teenagers and adults. One ingredient that has become significantly more sought-after due to the growth and popularisation of “skinfluencers”, is niacinamide. Niacinamide is applied topically to the skin, most commonly to the face, in the form of serums and creams. Despite its widespread use, there is little understanding within the consumer audience, regarding why exactly niacinamide is beneficial to the skin. Thus, I will outline a few of the advantages associated with the application of niacinamide.

Niacinamide is classed under the blanket term “Vitamin B3”, which refers to niacinamide and nicotinic acid, which function similarly due to their ability to convert into one another when absorbed into the epidermis. Niacinamide is known to be a powerful ingredient due to its array of abilities, including brightening, soothing redness, anti-ageing, hyperpigmentation and general improvement in hydration. The most notable benefit that niacinamide brings is that it significantly decreases the rate of transepidermal water loss. This is the process of the skin losing water from the dermis, through the epidermis, causing it to evaporate from the skin surface, thus leaving the skin dehydrated. The diagram below shows the three primary layers of human skin from top to bottom: the epidermis, dermis, and subcutis respectively.

The top layer of the skin is known as the epidermis. Many layers make up the epidermis including the stratum corneum (more commonly known as the horny layer due to its ability to protect the innermost layers of the skin, much like the horns of an animal that protect the animal itself), which is the outermost layer. The stratum corneum is a live tissue that consists of many specialised cells and keratin, and it is around 20 cells in thickness. This layer is especially vital as it carries out desquamation, the process of cells shedding and sloughing from its surface. It also performs various essential functions including water/hydration regulation and selective permeability to filter out toxins and irritants. As mentioned previously, one benefit of niacinamide is that it is able to increase moisture retention in the stratum corneum by reducing transepidermal water loss. This prevents unwanted visible  skin conditions that often accompany dryness, such as pronounced fine lines, wrinkles and hyperpigmentation. 

Niacinamide also strengthens the skin barrier, by stimulating the synthesis of ceramides. Ceramides are a family of lipid molecules that prevent irritation in the skin and hinder moisture loss, and act as the primary lipid constituent of lamellar sheets in intercellular spaces. They appear in the skin tissue in a solid crystalline / gel state, due to being saturated and long-chained, which means that membranes with lipid chains containing ceramides are less permeable than those that are liquid, which do not contain ceramides. This decreased permeability means that it is more difficult for water to diffuse out of the skin layers (which is heavily linked to the transepidermal water loss mentioned previously), and it allows the skin barrier function to be maintained as the skin acts as a shield against the entry of microorganisms. With the use of niacinamide, more ceramide molecules will be formed in the skin, meaning that the skin barrier is strengthened. This provides more protection against both moisture loss and the external environment. 

It is evident that niacinamide is an extremely useful ingredient in skincare products, for both aged / senescent skin and younger skin. I would personally recommend it to all skin types, as transepidermal water loss and weakened skin barrier are issues that both dry and oily skin types suffer from.