Why we use Zinc PCA

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What It Is

Zinc PCA is the zinc salt of L-pyrrolidone carboxylic acid. It's two components in one molecule. The zinc half delivers antimicrobial and sebum-regulating activity. The PCA half is a natural moisturising factor (NMF) — one of the molecules your skin already produces to hold water in the stratum corneum. Bonding zinc to PCA increases its bioavailability and skin penetration while adding a hydration mechanism that most zinc compounds lack.¹

How It Works

Skin

Zinc PCA inhibits 5α-reductase, the enzyme that converts testosterone to dihydrotestosterone (DHT). Less DHT at the sebaceous gland means less sebum production — directly addressing the upstream trigger of excess oil rather than just absorbing it at the surface. In vitro, zinc can completely inhibit 5α-reductase activity at sufficient concentrations, and the effect is potentiated by vitamin B6.²

It's also antimicrobial against P. acnes, disrupting the bacterial cell membrane to limit the colonisation that drives inflammatory breakouts.¹ And it suppresses inflammatory cytokine release — reducing the redness and swelling that accompany active lesions.

Beyond oil control: Zinc PCA suppresses UVA-induced activation of AP-1, a transcription factor that upregulates MMP-1 — the collagenase responsible for breaking down dermal collagen in photoaged skin. At the same time, it upregulates the SVCT2 ascorbic acid transporter, increasing vitamin C uptake into fibroblasts and enhancing type I collagen synthesis. One molecule that both protects existing collagen and supports new production.³

Scalp

The same 5α-reductase inhibition that controls facial sebum is directly relevant to scalp health. Excess DHT at the follicle is the primary driver of androgenetic alopecia, and sebum overproduction creates the conditions for Malassezia overgrowth — the fungal trigger behind seborrheic dermatitis, dandruff, and the chronic inflammation that compromises follicle function.²

Zinc PCA addresses both: it reduces the hormonal signal driving excess oil and targets the microbial consequence of it. Clinical evaluation of a cream containing zinc PCA (alongside piroctone olamine and stearyl glycyrrhetinate) showed significant reductions in erythema, desquamation, and pruritus in seborrheic dermatitis patients over 60 days.⁴ In a scalp context, that translates to a cleaner follicular environment — less clogging, less inflammation, better conditions for growth.

references

1 Abendrot, M., & Kalinowska-Lis, U. (2018). Zinc-containing compounds for personal care applications. International Journal of Cosmetic Science, 40(4), 319–327. Zinc-containing compounds for personal care applications
2 Stamatiadis, D., Bulteau-Portois, M. C., & Mowszowicz, I. (1988). Inhibition of 5 alpha-reductase activity in human skin by zinc and azelaic acid. British Journal of Dermatology, 119(5), 627–632. Inhibition of 5 alpha-reductase activity in human skin by zinc and azelaic acid
3 Takino, Y., Okura, F., Kitazawa, M., Iwasaki, K., & Tagami, H. (2012). Zinc L-pyrrolidone carboxylate inhibits the UVA-induced production of matrix metalloproteinase-1 by in vitro cultured skin fibroblasts, whereas it enhances their collagen synthesis. International Journal of Cosmetic Science, 34(1), 23–28. Zinc PCA inhibits UVA-induced MMP-1 and enhances collagen synthesis
4 Piérard-Franchimont, C., Piérard, G. E., & Kligman, A. (2019). Clinical and instrumental evaluation of a new topical non-corticosteroid antifungal/anti-inflammatory/antiseborrheic combination cream for the treatment of mild-to-moderate facial seborrheic dermatitis. Clinical, Cosmetic and Investigational Dermatology, 12, 103–108. Non-corticosteroid cream for mild-to-moderate facial seborrheic dermatitis