Effects of piroctone olamine on hair?

Benefit No. 1: piroctone olamine and its proven anti-dandruff properties.

Dandruff is a common scalp condition characterised by increased shedding of the stratum corneum, sometimes accompanied by itching and redness. This condition results from the dysbiosis of the scalp microbiome, primarily its over-colonisation by lipophilic yeasts of the genus Malassezia (increasing by a factor of 1.5 to 2, despite already accounting for 75% of the skin flora). Faced with this challenge, the cosmetics industry has developed numerous hair care products using antifungal agents, among which the piroctone olamine stands out for its efficacy in controlling concentrations of Malassezia commensals and reducing this undesirable flaking.

Well known in the cosmetic field for its preservative properties enabling the long-term preservation of products against bacterial proliferation and thus extending 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, evaluating the efficacy of piroctone olamine, among other parameters, on dandruff severity. These studies have mainly concentrated on the topical application of piroctone olamine in shampoo form, with study protocols generally extending over a duration of four weeks, although 20% of the studies opted for longer follow-up periods.

However, the majority of studies have investigated the effect of combining piroctone olamine with other antifungal agents, reflecting the synergistic approach favoured 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 first use by significantly reducing itching, dandruff and yeast proliferation Malassezia spp. Clinical data reveal particularly encouraging results: after six weeks of treatment, scalp dandruff is reduced by 81.7% with a shampoo containing 0.5% piroctone olamine, compared with 68.6% with a shampoo containing 0.5% zinc pyrithione.

This efficacy can be attributed to its ability to selectively 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, whilst exhibiting an excellent tolerability profile.

… Référence	Type of formulation	Sample size	Experimental conditions	Results
… WESSMAN C. & al (2000)	Shampoo containing 0.75% piroctone olamine plus 2% salicylic acid versus shampoo containing 1% zinc pyrithione	19 volunteers suffering from dandruff	Twice per week for 4 weeks; Contact time: 3–4 minutes per side	Both shampoos showed a significant reduction in dandruff. The combination of piroctone olamine and salicylic acid was slightly more effective than zinc pyrithione at reducing the severity and extent of scaling.
PIERARD G. E. & al (2002)	1% piroctone olamine shampoo versus 1% ketoconazole shampoo or 1% zinc pyrithione shampoo	150 men affected by dandruff	2 to 3 times per week for 6 months	Resolution of itching and dandruff within two to six weeks following three shampoo treatments (no statistical data)
KHANMOHAMMAD R. & al (2009)	Plant‐extract shampoo containing piroctone olamine versus shampoo containing climbazole	Two groups of 60 men with dandruff of equal severity (n = 120)	3 times per week for 5 weeks; scalp massage with 7.5 mL for 5 minutes	Complete resolution of dandruff in 55% of patients (versus 80% in the climbazole group) and reduction of dandruff in 45% of participants in the piroctone olamine group (versus 20% in the climbazole group) – disappearance of scalp itching and redness in 100% of patients
	Shampoo containing 0.5% piroctone olamine + 0.45% climbazole versus a shampoo with 1% zinc pyrithione	In vitro test: 5 pig skins; In vivo test: 88 subjects with moderate to severe dandruff	3 times per week for 4 weeks	In vitro antifungal efficacy equivalent to zinc pyrithione - equivalent dandruff reduction after 3 to 4 weeks - reduction in itching in 90% of subjects after 4 weeks
BAINES F. L. et al. (2013)	Shampoo containing 1% piroctone olamine and 0.5% climbazole versus shampoo containing only 1% piroctone olamine	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 four weeks plus two weeks of regression	Significant inhibition of the in vitro proliferation of Malassezia furfur by both shampoos, with superior efficacy shown by the piroctone olamine + climbazole shampoo – significant reduction of dandruff with both formulations, more pronounced with the piroctone olamine/climbazole combination, and maintenance of its superiority during the regression phase
MAX H. & al (2013)	Shampoo (piroctone olamine + climbazole) combined with an aqueous leave-in tonic (piroctone olamine + licochalcone A)	102 participants presenting with a moderate to very severe scalp flaking condition	3 times per week for 4 weeks by experienced hairdressers; 2 to 5 mL of tonic applied directly to the scalp at multiple sites, followed by massage and drying	There was a significant reduction in the amount of dandruff and in Malassezia growth following treatment with the anti-dandruff shampoo, either alone or in combination with the tonic; both anti-dandruff products elicited a significant decrease in the associated micro-inflammation, which was more marked with the shampoo/tonic combination.
`…` SHARIFI-RAD J. & al (2015)	Shampoo formulated with plant extracts containing 1% piroctone olamine + zinc PCA	30 patients suffering from dandruff	3 times per week for 2 months	Complete eradication of dandruff in 15 patients by the second week, in 12 after four weeks, and in three by the end of the fifth week
ZIANE S. & al (2016)	Alternating anti-dandruff shampoo (+0.5% piroctone olamine)/neutral shampoo (the same cleansing base without active ingredient)	41 subjects presenting a dandruff condition of mild to severe severity	12-week study divided into 3 phases: (1) 3 weekly applications of a neutral shampoo for the first 2 weeks; (2) 3 weekly applications of an anti-dandruff shampoo for the following 4 weeks; (3) 3 weekly applications of a neutral shampoo for the remaining 6 weeks	Reduction in scaling, itching, oiliness and redness observed over the four-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 (0.1%/0.1% PRO/CLZ, 0.1%/0.5% PRO/CLZ and 1%/0.1% PRO/CLZ), compared with a standard medical shampoo containing 2% ketoconazole	Malassezia sp. yeast strains (in vitro)	Inoculation of fungal strains using discs soaked in the samples for four days in a humid environment at 33 °C	Reduction in colony numbers; equivalent efficacy of the seven tested formulations to ketoconazole against the three strains Malassezia furfur, Malassezia globosa and Malassezia sympodialis
` tags and keep `BOSSLET M. (2025)	Pre-application gel (topical salicylic acid + piroctone olamine + zinc PCA) combined with a cleansing lotion (salicylic acid + piroctone olamine + antimicrobial peptide)	20 participants with moderate-to-severe seborrhoeic dermatitis of the scalp	Pre-application gel (before shampooing): once weekly for 4 weeks plus scalp massage Cleansing lotion (during shampooing): every 1 to 3 days for 12 weeks (contact time: 3 to 5 minutes)	80% clinical improvement rate at week 16, with significant improvement in dandruff, itching, erythema and greasiness

A contact time of 5 minutes is recommended when applying an anti-dandruff shampoo. The reduction in fungal density becomes increasingly significant as the contact time is extended.

Furthermore, the efficacy of piroctone olamine does not stop at the point of rinsing. It would exhibit a good adherence to the scalp and hair, allowing it to continue exerting its fungistatic properties well after application. In the study in vitro by FEY S. et al. (2011), the researchers sought to determine the skin substantivity of piroctone olamine (0.5%) and climbazole (0.45%) relative to that of the zinc pyrithione (1%), that is, the ability of an active substance 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 with only 0.55 μg/cm² for zinc pyrithione. However, it remains difficult to attribute this almost threefold difference specifically to piroctone olamine or to 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, offering the advantage of combining a cleansing action with an anti-dandruff action. Sulphate-free, its mild cleansing base improves the formula’s tolerability, rendering it suitable for scalps with heightened sensory sensitivity prone to dandruff.

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 the portions of hair sebum into oleic acid and other pro-inflammatory free fatty acids, which then penetrate the superficial layer of the scalp, causing inflammation and increased flaking of skin cells in susceptible individuals. Colonisation 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, via increased mitosis, persistent desquamation.

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 would 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 III (Fe³⁺) ions, essential elements for the energy metabolism of fungi. This iron chelation effectively inhibits the mitochondrial energy metabolism of pathogenic fungi, compromising their survival and proliferation.

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

Dandruff

R12 — Anti-Dandruff Treatment Shampoo
1% Piroctone Olamine + Jujube Extract — £21.90

Benefit No. 2: Piroctone Olamine, an active ingredient to slow down hair loss?

A randomised study in double-blind in 2002 conducted by Piérard et al. investigated the effects of various anti-dandruff actives on hair loss, including piroctone olamine. This study followed 150 men with mild to moderate dandruff associated with telogen effluvium, a temporary disruption of the hair growth cycle that manifests as episodes of hair shedding progressing towards hair miniaturisation which results from the early entry of numerous hairs into the telogen phase, often linked to androgenetic alopecia. Participants were randomly assigned to three groups that used shampoos containing either 1% ketoconazole, 1% piroctone olamine or 1% zinc pyrithione, applied two to three times per week for six months.

Men receiving the piroctone olamine shampoo observed a significant reduction in hair loss. The treated patients exhibited a significant 16.6% decrease in the number of hairs shed after six months’ 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), a result superior to that achieved with other tested actives such as ketoconazole (+4.9%) or zinc pyrithione (+6.8%).

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

Despite these encouraging data, caution is advised in the interpretation of these results. The study presents certain limitations: it did not include a control group using a neutral shampoo, making it difficult to assess the specific effect of the active ingredients. Its duration of six months remains relatively short for evaluating a chronic condition like alopecia, and it only involved men with both dandruff and androgenetic alopecia, which limits generalization. Additionally, the study was conducted over a period (autumn to spring) naturally associated with seasonal variations in hair loss.

How can this phenomenon be explained?

and Some studies have reported that the dandruff conditionand seborrheic dermatitis can lead to thinning of the hair shaft, a reduced percentage of hair in the anagen phase, an exacerbation of hair loss, and the development of acute telogen effluvium in connection with inflammatory disorders of the scalp. I nflammation of the scalp, scales, yeast proliferation, itching... all these factors can hinder hair growth and contribute to hair loss. In this study,

The authors suggest that the improvement observed following the action of piroctone olamine may result from the reduction of micro-inflammation in the scalp. Dandruff and seborrheic dermatitis create a chronic inflammatory environment, associated with the proliferation of Malasseziayeasts, which can disrupt the hair cycle and promote follicular miniaturisation characteristic of androgenetic alopecia. By cleansing the scalp and reducing this inflammation, piroctone olamine would thus create a more favourable environment for hair growth.

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

Benefit No. 3: Is piroctone olamine used as a conditioning agent?

In addition to its recognized action against dandruff, piroctone olamine might also be a hair conditioning agent, improving the manageability and appearance of hair. A study in vitro conducted in 2011 by FEY S. 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 on wet hair strands (n = 5), the shampoo containing piroctone olamine significantly reduced the force needed for combing wet hair by 35.2%, compared to only 12% with the zinc pyrithione shampoo. This significant difference suggests that piroctone olamine gives hair a softer and more manageable texture, making it easier for the comb to pass through the hair.

However, the study has some limitations. First of all, piroctone olamine was tested in combination with climbazole, which makes 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 application. The absence of a control group using a neutral shampoo, without antifungal actives, 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 reflect only one aspect of the consumer's overall sensory experience. Other parameters such as shine, volume, or styling hold were not assessed in this research.

How can piroctone olamine enhance the manageability of hair?

This improvement could be attributed to theaffinity of piroctone olamine with keratin, the main protein found in hair. By binding uniformly to the surface of 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 removed by rinsing, piroctone olamine is soluble, allowing it to distribute better and anchor more effectively to hair fibers and the scalp.

Furthermore, by purifying the scalp through its antifungal action against Malassezia yeast, piroctone olamine would create a more favourable environment for the production of higher-quality sebum, naturally contributing to the shine and suppleness of the hair.

The possibility of combining anti-dandruff effectiveness and conditioning properties in a single ingredient would represent a considerable advantage, especially given the chronic nature of dandruff requiring 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.