Zinc Gluconate: The skin benefits of this active substance.

Zinc gluconate is an active ingredient renowned for its sebum-regulating properties, making it a key component in various treatments for individuals with oily skin. From a biological perspective, the mattifying effects of zinc gluconate can be attributed to its ability to inhibit 5-α-reductase, the enzyme that catalyses the conversion of testosterone into dihydrotestosterone (DHT). It's worth noting that testosterone is the primary androgen in males and is also present in females.

Once DHT is formed, this hormone binds to a specific cytosolic receptor located in the sebaceous glands, which consequently increases their activity. We then observe a heightening of sebum synthesis. By inhibiting this process, zinc gluconate prevents the risk of skin pores being blocked by sebum, often responsible for the emergence of imperfections.

Zinc gluconate is also recognised for its anti-inflammatory properties and its ability to soothe the skin. This active ingredient works by inhibiting the release of the tumour necrosis factor TNF-α. This is a pro-inflammatory cytokine with both direct and indirect effects that exacerbate inflammation. TNF-α operates by releasing interleukins-1 and 6 (IL-1 and IL-6), other pro-inflammatory cytokines that heighten inflammation. By reducing the release of TNF-α, zinc gluconate helps to soothe the skin and protect it from inflammation.

Zinc gluconate is also credited with the ability to enhance the suppleness and elasticity of the skin. However, the scientific evidence supporting this claim remains weak. Nevertheless, one study involving 100 women aged 50 or older can be mentioned. For six months, the participants took two capsules daily containing various active ingredients, including 5 mg of zinc gluconate. At the end of these six months, the researchers observed using a cutometer a significant reduction in wrinkle depth, as well as an overall increase in skin hydration and suppleness.

It is, however, appropriate to exercise caution regarding this study and not to conclude that zinc gluconate alone has effects on skin elasticity. Indeed, the capsules consumed by the participants contained other active ingredients: among others, soy extract, white tea extract, vitamin C, vitamin E, and Roman chamomile extract. Therefore, we cannot assert that it was the zinc gluconate alone that improved skin suppleness, but only conclude that the combination of this active ingredient with those previously mentioned had positive skin effects.

The zinc gluconate also has proven antibacterial properties. It is particularly capable of inhibiting the growth of Cutibacterium acnes, the bacteria partly responsible for acne. While the mechanism by which this active ingredient works is not yet fully elucidated, it is nonetheless suggested that the zinc ions of zinc gluconate are capable of substituting for the magnesium ions involved in several enzymatic reactions essential to the development of bacteria. In doing so, zinc gluconate prevents their growth.

Studies have shown that zinc gluconate possesses antioxidant properties, enabling it to defend cells and cellular compounds against oxidative stress. This stress notably increases following exposure to UV rays or pollution and leads to the generation of free radicals. By forming mercapeptides with thiol groups attached to cell membranes, zinc inhibits the formation of free radicals.

Furthermore, it acts as a cofactor for the superoxide dismutase (SOD), an antioxidant enzyme that catalyses the dismutation of superoxide anions into oxygen and hydrogen peroxide. Thus, zinc gluconate has a protective effect on the skin and helps to delay skin sagging and the appearance of wrinkles, phenomena correlated with oxidative stress.

Zinc gluconate is also a valuable ally when it comes to aiding skin healing, after a minor injury or following inflammatory acne for instance. The topical application or oral intake of zinc gluconate stimulates the production of keratinocytes and fibroblasts. Let's remember that keratinocytes are the cells making up more than 85% of the epidermis and fibroblasts are the main cells of the connective tissue, playing a protective role. Thus, zinc gluconate promotes the synthesis of scar tissue.

Furthermore, this active ingredient promotes the expression of integrins, transmembrane proteins that allow cells to adhere to the macromolecules of the extracellular matrix. Beyond their adhesive function, integrins facilitate the migration of keratinocytes and contribute to the proper re-epithelialisation of wounds.

• SIGLER M. & al. Effect of a novel dietary supplement on skin aging in post-menopausal women. European Journal of Clinical Nutrition (2006).

• KALINOWSKA-LIS U. & al. Zinc-containing compounds for personal care applications. International Journal of Cosmetic Science (2018).

• LE FLOCH C. & al. Assessment of the Benefit of a Deep Cleansing Gel Containing Salicylic Acid 2%, Zinc Gluconate 0.2% and Lipohydroxy Acids 0.05% in Patients with Mild to Moderate Truncal Acne: Results from an Exploratory Study. Clinical, cosmetic and investigational dermatology (2023).