Zinc gluconate versus zinc picolinate: what are the differences?

The zinc gluconate is an active ingredient with the chemical formula C12H22O14Zn. It is particularly noted for its sebum-regulating properties, making it an ally for oily skin. From a biological perspective, zinc gluconate inhibits 5α-reductase, the enzyme catalysing the conversion of testosterone into dihydrotestosterone (DHT). The binding of DHT to a receptor of the sebaceous glands increases their activity and sebum synthesis. The zinc gluconate also inhibits the growth of Cutibacterium acnes, a bacterium involved in acne, making it a useful adjunct to anti-acne treatments.

Zinc gluconate is also recognised for its wound-healing properties and its ability to stimulate the production of scar tissue. Moreover, its anti-inflammatory activity, resulting from its ability to inhibit the release of TNF-α, a pro-inflammatory cytokine, makes it a valuable ingredient for soothing skin irritation. Finally, studies have shown that zinc gluconate also finds utility in hair applications and enables dandruff reduction by eliminating the fungi Malassezia, partly responsible for dandruff, and preventing hair loss. This final property is explained by its capacity to inhibit 5α-reductase and thus limit the production of DHT, a hormone that accelerates the entry of hair follicles into the telogen, or shedding, phase.

Beyond these effects, zinc gluconate may also be of interest in the context of the atopic dermatitis. This chronic inflammatory condition is underpinned by complex immune mechanisms, involving a dysfunction of the skin barrier, persistent inflammation and an imbalance in the immune response. Zinc is, however, a trace element essential for the proper functioning of the immune system and the skin barrier. Zinc deficiency can thus weaken the skin and promote the expression of pro-inflammatory mediators, contributing to the worsening of atopic lesions.

A study investigated the association between serum zinc levels and the pathophysiology of eczema. The investigators observed that the 168 patients with atopic dermatitis exhibited significantly lower zinc levels than the 137 healthy controls, alongside an overexpression of the chemokine CXCL10 in the epidermis, a molecule responsible for recruiting immune cells and perpetuating skin inflammation.

Administering zinc gluconate in a murine model reduced the release of CXCL10 by keratinocytes via activation of PPARα and inhibition of phosphorylation of STAT proteins involved in inflammatory signalling, and thus to mitigate eczema lesions.

These results suggest that zinc gluconate could help to modulate skin inflammation in atopic dermatitis, although additional clinical studies are still required to confirm its therapeutic potential in humans.

Zinc picolinate is another derivative of zinc, obtained through the chelation of picolinic acid by metallic zinc. Its chemical formula is C₁₂H₈N₂O₄Zn. Zinc picolinate is not widely present in cosmetic care, although it can be found in some shampoos, and is more commonly used as a dietary supplement. In this form, it helps to address zinc deficiencies and supports immune system function. Zinc picolinate is also found in supplements designed to aid the management of acne, skin inflammations and certain hair concerns. The properties of zinc picolinate are generally similar to those of zinc gluconate when taken orally.

Zinc picolinate is more commonly used in oral form due to its high bioavailability. Picolinic acid, a natural metabolite derived from the catabolism of tryptophan, acts as an effective chelator and facilitates the intestinal transport of zinc, thereby enhancing its absorption.

A comparative study conducted on fifteen participants assessed zinc absorption in various forms. It demonstrated that oral administration of zinc picolinate resulted in a slightly higher serum concentration than that observed with zinc gluconate or the zinc citrate. After four weeks of supplementation, serum zinc concentrations reached approximately 0.57 ppm for picolinate, compared with 0.56 ppm for citrate and 0.54 ppm for gluconate. Caution is required in interpreting these results due to the small sample size and the fact that only a single comparative study exists. Furthermore, the observed effects mainly reflect systemic action from oral supplementation and do not allow for conclusions regarding equivalent efficacy in topical application.

Zinc gluconate and zinc picolinate are two zinc derivatives with closely related biological properties, notably in terms of regulating inflammation and sebum production.

When considering the choice between zinc gluconate and zinc picolinate, it is important to take into account not only their effects but also their form of use and application context. Both can help reduce blemishes, soothe the skin and support hair health, but their uses differ.

In practice, the dilemma between zinc gluconate and zinc picolinate arises primarily depending on the route of administration. Zinc picolinate is almost exclusively used as a food supplement, due to its high bioavailability and efficient intestinal absorption. In contrast, zinc gluconate is distinguished by its great versatility: it is found both in food supplements and in topical formulations such as creams, lotions, masks or certain dermatological medicines. This compatibility with skin application is a major advantage of zinc gluconate.

The fact that zinc gluconate is now more widely employed than zinc picolinate does not necessarily mean it is intrinsically more effective. When comparing zinc gluconate with zinc picolinate, the distinction rests principally on the extent of available scientific documentation. Zinc gluconate benefits from a larger body of studies, which favours its integration into cosmetic treatments. Conversely, studies evaluating the clinical effects of zinc picolinate—particularly on skin and hair—remain more limited and relate primarily to oral supplementation.

Thus, the choice between zinc gluconate and zinc picolinate depends primarily on the objective sought: a localised action will favour zinc gluconate, whilst correcting a zinc deficiency or providing systemic support will more readily point towards zinc picolinate.

• BARRON P. & al. Comparative absorption of zinc picolinate, zinc citrate and zinc gluconate in humans. Agents and Actions (1987).

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

• SCHWARTZ J. & al. Zinc and skin health – Overview of physiology and pharmacology. Journal of Dermatological Treatment (2022).

• AL-NIAIMI F. & al. Zinc in dermatology. Journal of Dermatological Treatment (2022).

• LI D. & al. Zinc gluconate improves atopic dermatitis by modulating CXCL10 release of keratinocytes via PPARα activation. Biomedicine & Pharmacotherapy (2024).