Study finds esters fight dandruff and generate a healthy scalp microbiome

Research in Cosmetics suggests ester propanediol caprylate can influence bacterial flora toward a healthier scalp microbiome and reduce dandruff. An ester is a chemical substance made when an acid and an alcohol combine and water is removed. 

The study’s authors explain that the “synergistic effects” of using propanediol caprylate in different combinations allow reductions in the concentration of conventional anti-dandruff agents and preservatives.

After the EU banned zinc pyrithione, an ingredient used in hair products to battle dandruff, beauty companies have been searching for replacements that perform as well while maintaining a healthy scalp. Ester propanediol caprylate is already found in the final consumer product market.

The study points out that dandruff might be associated with dysbiosis of the scalp microbiome. Dysbiosis is a condition where the normal microbiome population structure is disturbed due to extrinsic factors like medications, diet, disease or genetic variants.

Dandruff affects approximately 50% of the global population. Its exact cause is not fully understood, but it is suspected to result from various intrinsic and environmental factors, including individual susceptibility, sebaceous secretion, immune response and microorganism activity.

Performance results 

The researchers were “surprised” to discover that ester use was associated with a lasting healthier scalp, in contrast to the usual return of dandruff upon discontinuation of anti-dandruff shampoo with conventional actives.

Dandruff shampoos can implement ester propanediol caprylate for a healthy scalp microbiome.Other topical solutions that fight the common skin condition include piroctone olamine, climbazole and salicylic acid.

Propanediol caprylate or propanediol undecylenate was tested in six in vivo studies in various cosmetic applications. The data showed efficacy comparable to climbazole and piroctone olamine.

Study subjects

The subjects were randomly assigned a control group, a group receiving shampoo with 0.5% climbazole and a group receiving shampoo with 0.5% propanediol caprylate.

The researchers performed microbiome analysis before the first product application, and the test shampoo was applied three times per week for 30 days.

After a 14-day conditioning period using a neutral shampoo, they applied a leave-on formulation once daily containing 0.5% propanediol caprylate or the control by spraying it onto the scalp.

The subjects rated the product’s efficacy via a questionnaire, and a trained technician scored dandruff on a scale of 0 to 10.

The relative abundance of staphylococcus decreased in the propanediol caprylate group from 64.0% to 61.9% but increased in the control group from 59.9% to 68.8%. Staphylococcus is a bacteria often found in high amounts in people with dandruff.