Rosmarinic acid as a bioactive compound in adult acne therapy: A controlled pilot clinical study

Acne vulgaris is a common chronic inflammatory skin disease that increasingly affects adults, particularly women. Therefore, there is growing interest in natural bioactive compounds with anti-inflammatory, antioxidant, and antimicrobial properties. One such compound is rosmarinic acid, a polyphenolic substance naturally present in plants of the Lamiaceae family. The aim of this study was to evaluate the effectiveness of rosmarinic acid in the treatment of acne vulgaris and to analyze the relationship between acne severity, dietary habits, and psychosocial factors. The study was conducted between February and June 2025 in a cosmetic clinic in Katowice, Poland. Thirty women diagnosed with acne vulgaris participated in the study and were randomly assigned to a study group (n=15) and a control group (n=15). The study group underwent a series of five cosmetic treatments using 5% rosmarinic acid. Acne severity was assessed using the Global Acne Severity (GEA) scale and the Global Acne Grading System (GAGS) before treatment and after three months. The results demonstrated a statistically significant reduction in acne severity in the study group according to both the GEA and GAGS scales (p<0.05). Additionally, a significant correlation was observed between acne severity and the Healthy Diet Index, as well as a negative correlation between acne severity and the frequency of fruit and vegetable consumption. The results of the T-QoL questionnaire indicated that acne had a measurable impact on the psychosocial functioning of participants.