What are the benefits of zinc gluconate on acne?

Acne is an inflammatory skin disease affecting nearly 80% of teenagers and young adults between 12 and 20 years old. It often results from a imbalance in the production of sebum . Those suffering from acne typically have an increased sebum synthesis by the sebaceous glands. While sebum is essential for the hydration and protection of the epidermis, an overproduction can cause blockage of the skin's pores and promote the appearance of imperfections, in the form of red spots or whiteheads , or even nodules or cysts in the case of severe acne.

Furthermore, this increased sebum synthesis results in a greasy environment on the skin's surface, which is conducive to the proliferation of the bacterium Cutibacterium acnes. This microorganism, naturally present in hair follicles, feeds on the triglycerides found in sebum. In doing so, it produces free fatty acids that cause inflammation of the sebaceous glands.

Finally, the epidermis of acne-prone skin does not exfoliate as well as it should, leading to an accumulation of dead cells on the skin's surface, which can also clog the pores. Indeed, this follicular hyperkeratosis forms a keratinous plug that hinders the normal flow of sebum.

Zinc, being unstable, cannot be directly incorporated into cosmetic products, which is why it is typically used in the form of zinc gluconate. This active ingredient, with the chemical formula C12H22O14Zn, is composed of two gluconate anions, each carrying a negative charge, and a zinc cation, bearing two positive charges. The zinc gluconate is primarily known for its anti-inflammatory properties and its matifying effects, making it a valuable ally for acne-prone skin.

• Zinc gluconate has sebum-regulating activity.

  The use of zinc gluconate helps to regulate sebum production, a property that is beneficial for individuals suffering from acne. Indeed, a decrease in sebum synthesis is associated with a lower risk of pore obstruction, and therefore, a reduced likelihood of blemishes appearing.

  From a mechanistic perspective, zinc gluconate functions by inhibiting 5-α-reductase, the enzyme that catalyses the conversion of testosterone into dihydroxytestosterone (DHT). It's important to note that testosterone is produced in both men and women, although its synthesis is lower in the latter. DHT is an androgen hormone that binds to a specific cytosolic receptor located in the sebaceous glands. This binding triggers an increase in the activity of the sebaceous glands, and thus intensifies the synthesis of sebum. Zinc gluconate acts upstream of this reaction cascade and helps to keep sebum production under control.

• Zinc gluconate possesses anti-inflammatory properties.

  Zinc gluconate can also function by reducing the inflammation of the sebaceous glands caused by acne. It has been particularly highlighted that this active ingredient is capable of inhibiting the production of the tumour necrosis factor TNF-α. This is a pro-inflammatory cytokine with both direct and indirect effects. TNF-α operates notably 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 possesses antibacterial properties.

  Zinc gluconate also works by fighting against Cutibacterium acnes, the bacteria partly responsible for acne. It inhibits the growth of these microorganisms and helps to regulate the populations present on the surface of our skin. Several mechanisms of action are considered by the scientific community to explain the antibacterial effects of zinc gluconate. One of the most popular is that the zinc ions of zinc gluconate substitute for the magnesium ions involved in several enzymatic reactions essential to the proper functioning of the bacteria. In doing so, zinc gluconate prevents its growth.

There are two primary ways to use zinc gluconate to combat acne: topical application and oral intake. Each method has its own advantages and disadvantages. Before choosing one method over the other, we recommend you seek advice from your doctor so they can provide guidance tailored to your situation.

• Topical application of zinc gluconate.

  Zinc gluconate often comes in the form of gels or creams to be applied locally to areas where acne tends to appear. It proves to be highly effective when applied topically and has been the subject of several studies. One of these recently examined the effects of a cleansing gel containing 2% salicylic acid and 0.2% zinc gluconate. It involved 51 patients suffering from mild to moderate acne who were asked to apply the product to a wet face morning and evening for at least 30 seconds before rinsing with warm water. After 84 days, the researchers observed a global reduction of 60% in lesions, both inflammatory and non-inflammatory combined.

• Oral intake of zinc gluconate.

  It is also possible to take zinc gluconate orally to combat acne, provided that the prescribed doses are strictly adhered to. It is generally recommended not to exceed 30 mg of zinc per day, which corresponds to 208 mg of zinc gluconate. A study on 30 patients notably showed that the daily administration of 30 mg of zinc gluconate for two months significantly reduced the number of inflammatory lesions. This treatment also helped to decrease the number of strains of Cutibacterium acnes resistant to erythromycin.

  Erythromycin is an antibiotic that was once commonly used against acne. Its use has gradually decreased as bacteria have become resistant to it over time. It would thus appear that the zinc gluconate and erythromycin combination could be an interesting approach to alleviate and limit acne outbreaks.

• RICHET H. & al. Effect of zinc gluconate on propionibacterium acnes resistance to erythromycin in patients with inflammatory acne: in vitro and in vivo study. European Journal of Dermatology (2005).

• 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).