Zincidone (Zinc PCA): how it works on oily skin

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Anyone who lives with oily skin knows the vicious cycle: they cleanse more to remove the oil, and the skin reacts by producing even more. Zincidone® is designed to intervene earlier, at the source of sebum production, rather than chase it.

What Zincidone is

Zincidone® is a biomineral complex of 100% natural origin that combines zinc and L-PCA (L-pyrrolidone carboxylic acid). In the INCI list, it appears as Zinc PCA. Zinc provides the sebum-regulating action, while L-PCA—a physiological molecule already present in the skin—improves its penetration and supports hydration. It is a COSMOS-certified active ingredient.

L'L-PCA is obtained by cyclizing L-glutamic acid, an amino acid of plant origin. Its combination with zinc is no coincidence: zinc alone penetrates poorly, but when bound to L-PCA, it becomes much more bioavailable. The result is an active ingredient that works on excess sebum without the downside typical of aggressive sebum regulators: dehydration.

The manufacturer's recommended use level ranges from 0.1% to 1%, with stability at a pH between 4 and 6.

How Zincidone works on oily skin

The documented mechanism is inhibition of 5-alpha-reductase, the enzyme that converts testosterone into dihydrotestosterone, the hormone that stimulates the sebaceous glands to work harder. Less activity from this enzyme means more measured sebum production.

Alongside this, L-PCA supports the function of the skin barrier, keeping the skin hydrated while reducing oiliness. That's the difference between mattifying and drying out: in the first case, the skin remains comfortable; in the second, it reacts by producing more sebum.

Efficacy data

The following data comes from the active ingredient manufacturer's efficacy dossier. We always indicate the source and experimental conditions for the figures we report: distinguishing an in vitro test from a skin study is part of interpreting the results correctly.

5-alpha-reductase inhibition (in vitro study)

In human fibroblasts pre-incubated with Zincidone®, anti-5-alpha-reductase activity was 65% higher than in the untreated control. In the same test, the effect was greater than that of zinc chloride at the same concentration: an experimental finding that credits L-PCA with better skin penetration.

Sebum-regulating activity (in vivo study)

Two groups of 16 female volunteers aged 19 to 25 with oily skin applied either a placebo cream or a cream containing 1% Zincidone® to half their forehead twice a day for 28 days, comparing each time with the untreated area. Sebumeter measurements after 28 days found a reduction in skin sebum of 22 µg/cm² in the treated area, while the placebo produced no significant effects.

One common misconception to watch out for: that 22 is not a percentage; it is an absolute change expressed in micrograms per square centimeter. We’re clarifying this because the figure is often reported as a “22% reduction in sebum,” which is something different.

Reduction in bacterial proliferation (test-tube study)

When Cutibacterium acnes was inoculated in a test tube with increasing dilutions of Zincidone®, the minimum inhibitory concentration was found to be between 0.1% and 0.25%. A second study also found antimicrobial activity against other microorganisms.

This finding needs to be interpreted precisely: these are in vitro tests on the raw ingredient, not measurements taken on skin. They describe how the ingredient behaves in the lab and explain why it is classified as a sebum-regulating ingredient with antibacterial action; they do not equate to an effect that can be claimed for the finished product on the skin flora of those who use it.

Who it's for

• Oily skin: overall shine, visible pores and makeup that slips throughout the day.
• Combination skin: an oily T-zone and normal or dry cheeks, where you need an active ingredient that mattifies without drying out the rest of your skin.
• Acne-prone skin: as cosmetic support for a targeted routine, including in adulthood. If blemishes appear after the age of thirty, the picture is different; learn more in our article on adult-onset acne.
• Scalp and oily roots: the same principle applies above the forehead, where excess sebum weighs hair down.

An important clarification: acne is a dermatological condition, not just a cosmetic concern. A well-formulated cosmetic product can support your skincare routine and improve the appearance of your skin, but for inflammatory, nodular or persistent forms, a dermatologist remains the right point of reference.

What other active ingredients it works with

Zincidone® works best in combination, because each of the active ingredients typically used for blemish-prone skin targets a different link in the chain.

The context in which these active ingredients work together, and the role of the skin microbiome, are explored in the dedicated article.

Zincidone in LeLang formulas

Acnerebal Serum combines Zincidone®, salicylic acid and niacinamide: it's the daily treatment for combination and oily skin prone to blemishes.

Acnerebal Cream completes the routine with an ultra-fluid texture and Azeloglycine®, for hydration without heaviness.

SkinPure Rebalance is the weekly purifying mask, where Zincidone® works alongside green clay: the clay absorbs existing sebum, while Zincidone helps regulate subsequent production.

Find the complete list of LeLang formulas containing it in the Zincidone ingredient page.

The complete routine for oily skin is described in the routine for oily skin and enlarged pores.

Frequently asked questions about Zincidone

What is Zincidone called in the INCI?

The label says Zinc PCA. Zincidone® is the trade name of the complex, while Zinc PCA is the official name of the molecule: the zinc salt of pyrrolidone carboxylic acid.

How long does it take to see results?

In the manufacturer's study, measurements were taken after 28 days of application twice a day. This timeframe is consistent with the skin renewal cycle: it is difficult to assess an oil-regulating ingredient before four weeks, and stopping after ten days is the most common mistake.

Does Zincidone dry out the skin?

This is precisely what sets it apart: L-PCA is a physiological molecule in the skin with a moisturizing function, so while zinc works on sebum, the PCA component maintains comfort and supports the skin barrier. It is still good practice to pair it with a lightweight cream, even on oily skin.

Is Zincidone of natural origin?

Yes. The manufacturer states that it is of 100% natural origin according to the ISO 16128 standard, with COSMOS certification. L'L-PCA is derived from L-glutamic acid, an amino acid of plant origin.

Can it be used during pregnancy?

Zinc PCA is a commonly used cosmetic ingredient, but during pregnancy and breastfeeding, the same rule applies to any skincare routine: it is best to check products with your gynecologist or dermatologist, especially if the same formula contains other active ingredients.

Zincidone or salicylic acid: which should you choose?

They are not alternatives, but complementary. L salicylic acid works on pores that are already clogged, while Zincidone® works on the amount of sebum produced. If the skin has many blackheads, salicylic acid is the first step; if the problem is shine returning a few hours after cleansing, Zincidone works on the cause. Well-formulated products contain both.

Is it also good for oily hair?

Yes, the same principle applies to the scalp, where sebaceous glands are numerous. It is found in balancing shampoos designed for roots that get weighed down quickly.

Sources for this article

• Technical data sheet and efficacy dossier from the active ingredient manufacturer, October 2020: in vitro study on human fibroblasts (5-alpha-reductase), in vivo study on two groups of 16 volunteers over 28 days (sebumetry), test tube study to determine the MIC on Cutibacterium acnes.
• INCI name: Zinc PCA, European Commission CosIng database.

On the website: Zincidone ingredient profile · Azeloglycine · salicylic acid · routine for oily skin