Niacinamide to improve the condition of oily skin?

Although it is suitable for all skin types, niacinamide would provide a benefit to oily skin. Apparently, it would help to regulate and balance excessive sebum production , thereby creating a mattified complexion, which in turn helps to prevent the appearance of comedonal and inflammatory lesions as well as minimise the visibility of dilated pores. Two parallel clinical trials have been conducted to evaluate the effect of 2% topical niacinamide on sebum production across different ethnicities.

1. SMILES K. and his team conducted a placebo-controlled clinical study with 100 Japanese subjects: 50 of them were instructed to apply twice a day over the entire face a hydrophilic gel containing 2% niacinamide and 1% D-panthenol as a humectant, and the other 50 used a placebo gel (without niacinamide or panthenol). While the sebum rate of both groups was not significantly different at the start of the study, the results revealed that the group treated with 2% topical niacinamide had a considerably lower sebum rate after 2 and 4 weeks of use (21.8% versus 10.6% in the placebo group).

2. Identical to the Japanese randomised study, 30 Caucasian participants (United States) were invited to apply a niacinamide-based gel (2%) to one half of their face for a period of 3 to 6 weeks and apply nothing to the opposite side. 6 weeks later, sebum levels were significantly reduced compared to the initial measurements.

Although this double-blind clinical study has shown that the topical use of niacinamide could potentially help reduce oily skin, the studies remain somewhat limited.

How does niacinamide reduce facial shine through its mode of action?

Whilst research has shown that topical niacinamide may be beneficial for oily skin, the cause of this sebum reduction has not yet been defined. Various scenarios are plausible, ranging from a decrease in sebum production by the sebaceous glands to an absorption of the sebum on the skin's surface.

However, researchers hypothesise that nicotinamide may have altered the path of sebum to the skin surface. This sebum-suppressing effect would be due to a "exfoliation" of the duct connecting the sebaceous gland to the skin surface at the level of the pilosebaceous orifice, thus encouraging a faster flow of sebum to the skin surface. Nevertheless, further studies are necessary in order to better characterise its mechanism of action in reducing sebum.

Furthermore, niacinamide has demonstrated its effectiveness in strengthening the skin barrier. INOUE S. & co. have shown that nicotinamide leads to an increase in the levels of ceramides and free fatty acids in the epidermis. This would then help to slow down the skin's tendency to produce too much sebum. Indeed, an impaired barrier function allows the penetration of irritants and allergens. To protect itself from external aggressions, the skin therefore starts to produce more sebum.