Effects of Piroctone Olamine on Hair?

The key takeaways on the effects of piroctone olamine on hair.

Numerous scientific studies and clinical trials have demonstrated the efficacy of piroctone olamine as an anti-dandruff agent, with reduction rates reaching over 80% after six weeks of treatment, thereby surpassing traditional agents like zinc pyrithione.
Piroctone olamine is said to provide a continuous protection against the proliferation of yeasts Malassezia between washes, thereby optimizing the benefits of each application.
A recent study suggests a potential benefit in preventing hair loss, thanks to its action on the balance of the scalp microbiome, which helps maintain a healthy scalp environment.
Beyond the fungistaticproperties, it may also provide additional potential benefits for hair quality.

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Benefit #1: Piroctone olamine and its documented anti-dandruff properties.

Dandruff is a common scalp condition characterized by increased desquamation of the stratum corneum, sometimes accompanied by itching and redness. This condition results from a dysbiosis of the scalp microbiome, primarily due to its overcolonization by lipophilic yeasts of the genus Malassezia (increased by a factor of 1.5 to 2, even though it already represents 75% of the skin flora). In response, the cosmetic industry has developed numerous hair care products utilizing antifungal agents, among which the piroctone olamine stands out for its effectiveness in controlling the concentrations of Malassezia commensal levels and reducing this undesirable flaking.

Well known in the cosmetic field for its preservative properties that sustainably protect products from bacterial proliferation and thus extend their shelf life, piroctone olamine has also proven particularly effective at reducing dandruff and scalp itching. This dual functionality makes it a preferred ingredient in modern hair care formulations.

Piroctone olamine has a clinically proven history of efficacy. To date, over 15 clinical trials involving several hundred participants have been documented, assessing the efficacy of piroctone olamine, among other outcomes, on the dandruff condition. These studies have primarily focused on the topical application of piroctone olamine in shampoo form, with study protocols generally lasting four weeks, although 20% of the studies opted for longer follow-up periods.

On the other hand, the majority of studies have investigated the effect of combining piroctone olamine with other antifungal agents, reflecting the synergistic approach favored in the development of anti-dandruff products. Only a few studies have evaluated the effect of piroctone olamine used alone on dandruff clearance, which can sometimes complicate the specific attribution of the observed beneficial effects.

Most often formulated at concentrations ranging from 0.5% to 1% in shampoos, piroctone olamine demonstrates its efficacy from the very first use by significantly reducing itching, dandruff, and the proliferation of yeasts Malassezia spp. Clinical data show particularly encouraging results: after six weeks of treatment, scalp dandruff decreases by 81.7% with a shampoo containing 0.5% piroctone olamine, compared to 68.6% with a shampoo containing 0.5% zinc pyrithione.

These results can be explained by its ability to specifically target the yeast Malassezia, thereby restoring the balance of the scalp microbiome. Comparative studies demonstrate that shampoos containing piroctone olamine significantly reduce dandruff and associated symptoms, with an excellent tolerability profile.

Référence	Formulation type	Sample size	Experimental conditions	Results
… WESSMAN C. & al (2000)	Shampoo containing 0.75% piroctone olamine and 2% salicylic acid versus shampoo containing 1% zinc pyrithione	19 volunteers suffering from dandruff	Twice weekly for 4 weeks; Contact time: 3 - 4 minutes per side	Significant reduction in dandruff condition was observed with both shampoos. The piroctone olamine + salicylic acid combination was slightly more effective than zinc pyrithione in reducing both the severity and the area affected by scaling.
`…` PIERARD G. E. & al (2002)	1% piroctone olamine shampoo versus 1% ketoconazole shampoo or 1% zinc pyrithione shampoo	150 men afflicted with dandruff	2 to 3 times per week for 6 months	Itching and dandruff disappeared within 2 to 6 weeks using all three shampoos (no statistical data available)
KHANMOHAMMAD R. & al (2009)	Shampoo with plant extracts containing piroctone olamine versus shampoo with climbazole	Two groups of 60 men presenting with dandruff of similar severity (n = 120)	Three times per week for five weeks; scalp massage with 7.5 mL for five minutes	Complete resolution of dandruff in 55% of patients (versus 80% in the climbazole group) and reduction of dandruff in 45% of subjects in the piroctone olamine group (versus 20% in the climbazole group) - elimination of scalp itching and redness in 100% of patients
FEY S. et al. (2011)	Shampoo containing 0.5% piroctone olamine and 0.45% climbazole versus shampoo containing 1% zinc pyrithione	In vitro test: 5 pig skins; in vivo test: 88 subjects with a moderate to severe dandruff condition	3 times per week for 4 weeks	Antifungal efficacy equivalent to zinc pyrithione in vitro - Comparable dandruff reduction after 3 to 4 weeks - Itch reduction observed in 90% of subjects after 4 weeks
` and ` BAINES F. L. & al (2013)	Shampoo containing 1% piroctone olamine + 0.5% climbazole versus shampoo containing 1% piroctone olamine alone	In vitro test: Malassezia sp. yeast strains. In vivo test: 69 male subjects with dandruff.	In vitro test: Inoculation of fungal strains with sample-soaked discs for 24 hours at 32 °C In vivo test: Three times per week for 4 weeks, followed by a 2-week regression period	Significant in vitro inhibition of Malassezia furfur proliferation by both shampoos, with greater efficacy for the piroctone olamine + climbazole shampoo – significant reduction in dandruff with both shampoos, more pronounced with the piroctone olamine/climbazole formulation, with its superiority maintained during the regression phase
MAX H. & al (2013)	Shampoo (piroctone olamine + climbazole) combined with a leave-on aqueous tonic (piroctone olamine + licochalcone A)	102 participants exhibiting moderate to very severe dandruff	Administered by experienced hairdressers three times per week for four weeks; 2–5 mL of tonic was applied directly to multiple sites on the scalp, followed by massage and hair drying	Significant reduction in dandruff levels and in Malassezia growth following treatment with the anti-dandruff shampoo alone or in combination with the tonic; significant decrease in associated micro-inflammation with both anti-dandruff products, more pronounced with the shampoo/tonic combination
SHARIFI-RAD J. & al (2015)	Shampoo with plant extracts containing 1% piroctone olamine + zinc PCA	30 patients suffering from dandruff	Three times per week for two months	Complete dandruff elimination occurred in 15 patients by the second week, in 12 after four weeks, and in 3 by the end of the fifth week.
ZIANE S. et al. (2016)	Alternating use of anti-dandruff shampoo (0.5% piroctone olamine) and a neutral shampoo (same cleansing base without active ingredient)	41 subjects presenting a flaky scalp condition ranging in severity from mild to severe	12-week study divided into three phases: (1) three applications per week of a neutral shampoo during the first two weeks; (2) three applications per week of an anti-dandruff shampoo during the following four weeks; (3) three applications per week of a neutral shampoo during the remaining six weeks.	Reduction in scaling, itching, greasiness, and redness observed over the 4-week treatment period
AKBABA G. & al (2024)	7 formulations of different concentrations of piroctone olamine (PRO) and climbazole (CLZ) (0.1% PRO, 1% PRO, 0.1% CLZ, 0.5% CLZ), or both combined (0.1%/0.1% PRO/CLZ, 0.1%/0.5% PRO/CLZ, and 1%/0.1% PRO/CLZ), compared to a standard medicated shampoo containing 2% ketoconazole	Malassezia sp. yeast strains (in vitro)	Inoculation of fungal strains with sample-soaked disks for 4 days under humid conditions at 33°C	Reduction in colony counts; The seven tested formulations were as effective as ketoconazole against the three strains Malassezia furfur, Malassezia globosa, and Malassezia sympodialis
`…` BOSSLET M. (2025)	Pre-application gel (topical salicylic acid + piroctone olamine + zinc PCA) in combination with a cleansing lotion (salicylic acid + piroctone olamine + antimicrobial peptide)	20 participants presenting with moderate-to-severe seborrheic dermatitis of the scalp	Pre-application gel (pre-shampoo): once weekly for 4 weeks + scalp massage Cleansing lotion (during shampooing): every 1 to 3 days for 12 weeks (dwell time: 3 to 5 minutes)	Clinical improvement rate of 80% at week 16, with significant improvement in dandruff, itching, erythema, and greasiness

A 5-minute contact time is recommended when performing an anti-dandruff shampoo. The reduction in fungal density becomes increasingly significant the longer the contact time is.

Furthermore, the efficacy of piroctone olamine does not end with rinsing. It displays a good adhesion capacity to the scalp and hair, allowing it to continue exerting its fungistatic properties well after application. In the in vitro study by FEY S. et al. (2011), the researchers aimed to determine the skin substantivity of piroctone olamine (0.5%) and climbazole (0.45%) compared to that of the zinc pyrithione (1%), i.e. the ability of an active ingredient to remain on its substrate after rinsing, using porcine skin samples as a model. After washing and rinsing, 1.93 μg/cm² of combined piroctone olamine and climbazole remained on the skin compared to only 0.55 μg/cm² for zinc pyrithione. However, it remains difficult to attribute this nearly threefold difference specifically to piroctone olamine or climbazole, as both actives were tested together. Moreover, the exact mechanism explaining the superior substantivity of piroctone olamine remains to be determined by further studies. Nevertheless, this prolonged retention on the skin allows piroctone olamine tocontinuously inhibit yeast growth between applications.

Our anti-dandruff shampoo contains 1% piroctone olamine, delivering the dual benefit of cleansing and anti-dandruff activity. Sulfate-free, its mild surfactant base enhances the formulation’s tolerance, making it suitable for the heightened sensory sensitivity of dandruff-prone scalps.

By what mechanism does piroctone olamine act on dandruff?

To understand the action of piroctone olamine, one must first grasp the mechanism of dandruff. This condition is based on the concept that the fungus Malassezia is involved in the pathogenesis. The pathological process results from the activity of an enzyme called lipase, produced by the fungus Malassezia. This enzyme breaks down by lipolysis theportions of scalp sebum into oleic acid and other proinflammatory free fatty acids, which then penetrate the superficial layer of the scalp, causing inflammation and increased desquamation of skin cells in susceptible individuals. Colonization of the scalp by these fungi also induces the production of oxidative enzymes and pro-oxidant metabolites generated by microbial peroxidases, creating a vicious cycle of skin irritation and, through increased mitosis, persistent scaling.

It has been observed that piroctone olamine effectively reduces the level of Malassezia furfur (formerly Pityrosporum ovale), and alters the composition of lipids and fats on the scalp. Although the mechanism of action is not yet fully elucidated, it is believed to have the capacity to influence fungal growth. Indeed, piroctone olamine appears capable of penetrating the cell membrane of pathogenic microorganisms. Once inside, it forms stable complexes with iron(II) (Fe²⁺) and iron(III) (Fe³⁺) ions, essential elements for fungal energy metabolism. This iron chelation effectively inhibits the mitochondrial energy metabolism of pathogenic fungi, compromising their survival and proliferation.

Piroctone olamine not only fights dandruff but also enhances overall scalp health by reducing inflammation and sebum production. Less Malassezia = fewer lipases = less breakdown of sebum into pro-inflammatory free fatty acids. This helps create an optimal environment for hair growth and maintenance.

92,86%*

Volunteers reported a decrease in the number of scales after using our R12 anti-dandruff treatment shampoo.

Benefit #2: Piroctone olamine, an active ingredient to slow down hair loss?

A 2002 randomized double-blind study conducted by PIÉRARD et al. investigated the effects of various anti-dandruff agents on hair loss, including piroctone olamine. This research followed 150 men with mild to moderate dandruff associated with telogen effluvium, a temporary disruption of the hair growth cycle characterized by episodes of hair shedding progressing to hair miniaturization resulting from the premature transition of many hairs into the telogen phase, often linked to androgenetic alopecia. Participants were randomly assigned to three groups using shampoos containing either 1% ketoconazole, 1% piroctone olamine, or 1% zinc pyrithione, applied two to three times per week over six months.

Men who received the piroctone olamine shampoo observed a significant reduction in their hair loss. The treated patients exhibited a significant 16.6% reduction in the number of hairs lost after six months of use (ketoconazole: 17.3%; zinc pyrithione: 10.2%). This improvement was accompanied by a 7.9% increase in the proportion of hairs in the active growth phase (anagen phase), a result superior to that obtained with the other active agents tested, such as ketoconazole (+4.9%) or zinc pyrithione (+6.8%).

Meanwhile, the study also highlighted an effect of piroctone olamine on hair thickening. The average diameter of hair shafts increased by 7.7% after six months of use, whereas ketoconazole produced only a 5.4% improvement and zinc pyrithione caused a slight thinning of the hair (-2.2%). Finally, this thickening correlated with a slight reduction in sebum production, suggesting an overall improvement in scalp balance.

Despite these encouraging data, caution is warranted in interpreting these results. The study has certain limitations: it did not include a control group using a neutral shampoo, which makes it difficult to assess the specific effect of the active ingredients; its six-month duration is relatively short for evaluating a chronic condition such as alopecia; and it included only men with both dandruff and androgenetic alopecia, limiting generalizability. Moreover, the study was conducted during a period (fall - spring) naturally associated with seasonal variations in hair shedding.

How can we explain this phenomenon?

Certain studies have reported that thedandruff condition and seborrheic dermatitis can lead to thinning of the hair shaft, a reduced percentage of hairs in the anagen phase, an exacerbation of hair loss, and the development of acute telogen effluvium associated with inflammatory scalp disorders. Inflammation of the scalp, flakes, yeast proliferation, itching... all these factors can inhibit hair growth and contribute to hair loss. In this study,

The authors suggest that the observed improvement following the action of piroctone olamine results from the reduction in scalp microinflammation. Dandruff and seborrheic dermatitis create a chronic inflammatory environment associated with the proliferation of yeasts Malassezia, which can disrupt the hair cycle and promote the follicular miniaturization characteristic of androgenetic alopecia. By cleansing the scalp and reducing this inflammation, piroctone olamine thus creates a more favorable environment for hair growth.

This quantified data indicates that piroctone olamine, beyond its anti-dandruff action, could represent a potentially interesting asset in the overall management of hair loss. However, it would be premature to consider it as an established treatment for hair loss. Additional studies on larger populations and over longer durations would be necessary to confirm these promising effects.

Benefit #3: Piroctone olamine as a conditioning agent?

In addition to its known action against dandruff, piroctone olamine might also be a hair conditioning agent, improving the manageability and appearance of hair. An in vitro study conducted in 2011 by S. FEY and his team evaluated the effects of a shampoo containing 0.5% piroctone olamine combined with 0.45% climbazole compared to a shampoo with 1% zinc pyrithione on 98 volunteers suffering from moderate to severe dandruff.

In a combing test conducted on wet hair strands (n = 5), the shampoo containing piroctone olamine significantly reduced the force required for wet hair combing by 35.2% compared to only 12% with the zinc pyrithione shampoo. This significant difference suggests that piroctone olamine imparts a softer and more manageable texture to the hair, making it easier for the comb to pass through.

However, the study has some limitations. First, piroctone olamine was tested in combination with climbazole, making it difficult to attribute the conditioning effects solely to piroctone olamine. Furthermore, the combability test was conducted on hair strands in vitro, rather than on human subjects, which limits the relevance of the results for real-world applications. The absence of a control group using a neutral shampoo without antifungal agents prevents distinguishing the effect of the active ingredients from that of the shampoo's cleansing base. It should also be noted that while combability measurements are objective, they only reflect one aspect of the overall sensory experience for the consumer. Other parameters such as shine, volume, or styling hold were not evaluated in this research.

How can piroctone olamine improve hair manageability?

This improvement might be explained by theaffinity of Piroctone Olamine with keratin, the main protein in hair. By uniformly binding to the surface of the hair shafts, it smooths the cuticle, reduces friction between strands, and enhances the softness and shine of the hair.

Unlike zinc pyrithione, which forms a dispersion of solid particles in aqueous formulations that can be easily washed away, piroctone olamine is soluble, allowing it to distribute more evenly and anchor more effectively to hair fibers and the scalp.

Additionally, by cleansing the scalp through its antifungal effect against Malassezia yeasts, piroctone olamine would create a more favorable environment for the production of higher-quality sebum, naturally contributing to the shine and suppleness of the hair.

The possibility of combining anti-dandruff efficacy and conditioning properties into a single ingredient would represent a considerable advantage, especially given the chronic nature of dandruff which requires the continuous use of an anti-dandruff shampoo. However, further studies, including in vivo tests on human subjects and isolating piroctone olamine, would be necessary to confirm this conditioning potential.