Squalene Peroxidation in Acne Vulgaris: Linking Sebum Oxidation to Inflammation and Comedogenesis


Acne vulgaris is a skin condition that affects millions of people worldwide and can cause significant emotional distress. The current treatments primarily target bacterial colonization and sebum production and often provide inconsistent results because they do not address the oxidative stress and lipid peroxidation that can worsen acne. One of the emerging areas of interest in understanding acne development is the role of squalene peroxidation. Squalene constitutes about 10-15% of the total sebum lipid content and highly susceptible to oxidation due to the presence of multiple double bonds which makes it a prime candidate for peroxidation where oxidative degradation of squalene can form squalene monohydroperoxides, which are highly comedogenic and can worsen the inflammatory processes associated with acne. The peroxidation of squalene is believed to be triggered by UV radiation, environmental pollutants, and the presence of Cutibacterium acnes bacteria on the skin. To this end, new study published in Pharmaceuticals Journal and conducted by PhD student Giorgia Condrò, Roberta Sciortino, and Professor Paola Perugini from the Department of Drug Sciences at the University of Pavia developed a new in vivo method to extract and quantify squalene from acne-prone skin and correlated their findings with biophysical skin parameters including sebum content, protein levels, and transepidermal water loss (TEWL).

First, the researchers performed an in vitro experiment to quantify the number of peroxides formed in squalene when exposed to oxidative conditions and used sodium thiosulfate titration to measure the peroxide number, which indicates the amount of hydroperoxides present.  They exposed the samples to a solar simulator to mimic the oxidative stress induced by UV radiation and found that squalene exhibited a significant increase in peroxidation which indicates its high susceptibility to oxidative degradation compared to the controls. Afterward, the authors extracted and quantified squalene from acne-prone and healthy skin where they collected sebum samples using D-Squame adhesive discs from the forehead, chin, cheeks, and shoulders of both acneic and healthy volunteers then analyzed the extracted sebum using high-performance liquid chromatography (HPLC) and found a substantially higher concentration of squalene in acne-prone skin. The team also found that highest concentrations of peroxide squalene to be in the forehead (7.3%) and notable amount in the inflamed chin 4.7%, and the non-inflamed chin 2.9%. This differential distribution of peroxide squalene highlights its potential role in localized inflammation and comedogenesis. Moreover, the authors measured several biophysical parameters of the skin, including pH,  TEWL, protein content, and sebum levels and found that acne-prone skin had higher TEWL and protein content indicative of a compromised skin barrier function. Additionally, sebum levels were significantly higher in acneic subjects, and correlated with the increased presence of squalene and its peroxide form. In conclusion, the study conducted by Giorgia Condrò, Roberta Sciortino, and Professor Paola Perugini provided compelling evidence that squalene and its oxidized form, peroxide squalene, are significantly elevated in acne-prone skin compared to healthy skin which shows the pathogenic role of lipid peroxidation in the development of acne, particularly in forming comedones and inflammatory lesions. Moreover, squalene and its peroxide could act as lipid biomarkers for acne-prone skin which can be used as a new tool for better diagnosis and monitoring acne severity and progression, and provide a more targeted approach to acne management. Their findings also suggests that oxidative stress plays an important role in acne development, therefore, therapeutic strategies that target and reduce oxidative stress could be highly effective including the use of antioxidants and drugs that inhibit lipid peroxidation, potentially offering a new acne treatment. Additionally, sunscreens and skincare products that have antioxidant ingredients can be recommended to protect the skin from oxidative stress and reduce the risk of acne flare-ups.

About the author

Prof. Paola Perugini, PhD, Professor at the Department of Drug Sciences, University of Pavia, Scientific Director of Etichub s.r.l., Academic spin-off University of Pavia, Italy

Paola Perugini has a degrees in Chemistry and Pharmaceutical Technology cum laude and in Pharmacy. In 1998 she obtained her PhD degree in Chemistry and Pharmaceutical Technology and in 2000  she obtained the qualification at the “Industrial Pharmacy” specialization school.

She is a professor in the Pharmaceutical and Cosmetic Technology fields at the Department of Drug Sciences at the University of Pavia since 2001.

She is Director of the Second Level Master Course in Cosmetological Sciences at the University of Pavia.

She is Founder and Scientific Director of Etichub s.r.l., Academic spin-off of the University of Pavia since 2013. Her research fields concerning pharmaceutical and cosmetic technology led to several patents and  more than  150 international publications and congress presentations. In cosmetic field Dr. Paola Perugini received the Young Maison de Navarre award for a research regarding studies on photostability of sunscreens.

About the author

Giorgia Condrò has a background in pharmaceutical and medical biotechnology and is currently pursuing her PhD in Chemical, Pharmaceutical and Industrial Innovation Sciences at the University of Pavia under the guidance of Professor Paola Perugini. Her research is focused on the development of new pharmaceutical and cosmetic systems aimed at treating, preventing and restabilizing alterations in the skin microbiota. Through her work, Giorgia aims to contribute to advances for skin dysbiosis with strategies aimed to harness the potential of the skin microbiota to improve skin health and well-being.

About the author

Roberta Sciortino graduated in Pharmaceutical Chemistry and Technology from the University of Pavia. During her studies, she conducted a thesis internship in a cosmetic and pharmaceutical technology laboratory under the guidance of Professor Paola Perugini. In this role, she collaborated with Giorgia Condrò on a PhD project focusing on the study of skin microbiota, specifically in the development and implementation of a protocol for extracting squalene from volunteers. Currently, Roberta is employed as a Quality Control Analyst at Hering S.r.l.


Condrò G, Sciortino R, Perugini P. Squalene Peroxidation and Biophysical Parameters in Acne-Prone Skin: A Pilot “In Vivo” Study. Pharmaceuticals (Basel). 2023 Dec 8;16(12):1704. doi: 10.3390/ph16121704.

Go To Pharmaceuticals (Basel).