Zinc Gluconate: What are its hair benefits?

Zinc gluconate is primarily known for its sebum-regulating properties, which are beneficial for oily skin types as well as scalps that quickly become greasy. It is therefore frequently used in the formulation of shampoos or purifying treatments.

Zinc gluconate acts on the sebaceous glands by inhibiting 5-α-reductase, the enzyme that catalyses the transformation of testosterone into dihydrotestosterone (DHT). When DHT binds to a specific cytosolic receptor in the sebaceous glands, it triggers an intensification of their activity, which results in an increase in sebum production. By inhibiting this process, zinc gluconate helps combat oily hair. Regular use of a hair care product containing zinc gluconate can assist individuals whose hair quickly becomes greasy in controlling sebum production at the scalp level and may allow them tospace out their shampoos.

Just like the skin on the rest of the body, the scalp can be prone to irritation or itching. Zinc gluconate has a soothing effect and helps to reduce these discomforts. This active ingredient is indeed capable of inhibiting the release of the tumour necrosis factor TNF-α. TNF-α is a pro-inflammatory cytokine with direct and indirect effects that exacerbate inflammation. It acts in particular 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 alleviate scalp irritation and provide relief.

It is not uncommon to have dandruff. This hair inconvenience indeed affects about one in two people. Dandruff can be caused by various factors, such as hyperseborrhea, which is a high production of sebum by the sebaceous glands, or even colonisation by fungi of the type Malassezia. These pathogens thrive particularly in greasy environments where they feed on the triglycerides present in the sebum. However, by hydrolysing these molecules, the Malassezia release pro-inflammatory mediators.

Zinc gluconate has a dual action on dandruff. In addition to its sebum-regulating properties that combat excess oil, this active ingredient also has a antifungal activity against these fungi. The mechanism at work has not yet been fully elucidated, but studies have shown that zinc gluconate can inhibit the growth of Malassezia.

Zinc gluconate can also be used to strengthen hair and reduce the risk of hair loss. This property is derived from its inhibitory action on 5-α-reductase, the enzyme responsible for converting testosterone into dihydrotestosterone (DHT). Indeed, DHT intensifies the activity of interleukin-6 (IL-6), cytokines that speed up the transition between the growth and rest phases of hair. DHT thus causes hair follicles to enter the telogen phase, or hair shedding phase, more quickly. By inhibiting 5-α-reductase, zinc gluconate thus protects hair from hormonal fluctuations or genetic predispositions leading to increased production of DHT and consequently hair loss.

Furthermore, it has been demonstrated that zinc gluconate has a inhibitory effect on trypsin, a proteolytic enzyme. The scientific community suggests that trypsin may promote hair loss by affecting a signalling pathway mediated by a receptor that leads to the death of follicular papilla cells. At present, these are only assumptions, as the study that proposed this hypothesis was conducted on rats.

Zinc gluconate also has a conditioning effect on hair due to its ability to form complexes with certain metallic ions responsible for the oxidation of keratin fibres. This chemical reaction prevents the metallic ions from damaging the hair.

Furthermore, zinc gluconate is a cofactor of the superoxide dismutase (SOD), an antioxidant enzyme that catalyses the dismutation of superoxide anions into oxygen and hydrogen peroxide. This active ingredient thus participates in the neutralisation of free radicals before these reactive species weaken the hair bulb and hair fibres, thereby promoting the appearance of split ends. The hair application of zinc gluconate therefore has a protective effect on the hair and limits the effects of exposure to UV radiation and pollution, elements that generate oxidative stress.

• SHAPIRO S. & al. Trypsin-induced follicular papilla apoptosis results in delayed hair growth and pigmentation. Developmental dynamics (1997).

• GAZZANIGA G. & al. Anti-dandruff and anti-oily Efficacy of Hair formulations with a Repairing and Restructuring activity. The Positive Influence of the Zn-Chitin Nanofibrils Complexes. Journal of applied cosmetology (2012).

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