Tangkijngamvong N, et al. - Researchers conducted a four-week clinical trial with 40 people in order to discover the effectiveness of chitosan particles (CP) formulation on controlling sebum secretion, its extended impacts on skin redness and texture after combining with proretinal nanoparticles (CP-PRN), and a correlation of the clinical grading with sebum levels that affect mental health. People applied either CP formulation or CP-PRN during nighttime. In comparison with baseline, both CP and CP-PRN notably decreased sebum levels at week 4. Throughout the study, CP also resulted in notable decreases in transepidermal water loss and skin corneometry. Overall, the anti-sebum effect showed by chitosan particles. Moreover, it could be mixed with PRN to increase benefits without losing the sebum controlling effect. In practice, clinical grading might be useful due to a modest correlation with sebum levels.