97 Peptide Effects on Photoaging The improvement in UV acne was significantly more pronounced in the treatment group than in the control group (Figure 4). ADVERSE REACTIONS Among the 80 subjects, 2 subjects in the treatment group developed mild erythema, minor scaling, and mild pruritus in the second week of treatment, which were all tolerable. All symptoms were cured spontaneously after 1 week. No adverse reactions such as persistent erythema, blistering, profuse scaling, or severe pruritus were observed. DISCUSSION In this study, there was no significant improvement in facial wrinkles and color spots, but the dermoscopic observations revealed reduction in the number of fine wrinkles, improvement in the depth and length of coarse wrinkles, and lighter color spots in some subjects in the peptide complex cream group. In this study, DPAS scores of the peptide complex cream group were significantly decreased at week 8, indicating that the peptide complex cream was capable of significantly improving the signs of photoaging in the subjects. Although improvements in facial hyperpigmentation and wrinkles were observed through skin microscopy, the calculated DPAS scores showed only slight differences. These differences may be attributed to the fact that DPAS scores are based on the quantity of hyperpigmentation and wrinkles without considering changes in the color of hyperpigmentation or the depth of wrinkles. Therefore, even if the color of hyperpigmentation lightens and the depth of wrinkles diminishes, the DPAS scores remain unchanged due to the unchanged quantity Figure 4. Changes in UV acne parameters in subjects in the peptide complex cream group and the base cream group. Data expressed as mean ± SEM *indicates the p-value between the treatment and control groups, and *indicates P .05.

98 JOURNAL OF COSMETIC SCIENCE of hyperpigmentation and wrinkles. This difference explains the minor disparities observed in the statistical results of hyperpigmentation and wrinkles in our study. Results from the FS-1200 measurement showed significant improvement in UV acne in the peptide complex cream group at weeks 2 and 4. These results show that although the peptide complex cream cannot significantly improve facial spots and wrinkles in a short time, it can reduce the score of DPAS and comprehensively improve facial photoaging symptoms. Additionally, the subjective rating of wrinkles has a wide range, making it suitable for preliminary screening but not for evaluating subtle changes. Therefore, the results of subjective wrinkle rating were also not significant. Future research should consider selecting more appropriate tools for assessing wrinkles and pigmentation deposition. The results of this study would have been more accurate if the left and right sides of the face were used as the treatment and control, respectively, but since the subjects found this protocol hard to accept, it was not implemented in the end. According to literature reports, the core components (three polypeptides) of the peptide complex cream have the effect of improving wrinkles and color spots. Applying carnosine- containing creams to the face could alleviate skin dryness and make skin firmer and more supple.8-10 Palmitoyl pentapeptide-4, a derivative of KTTKS, can achieve the antiaging effects of wrinkle reduction and skin texture improvement by stimulating production of the extracellular matrix and type I and type III collagen.4,11 Acetyl hexapeptide-8, also known as argireline, can reduce the repetitive contraction of the muscles of facial expression by competitive inhibition, thus attaining anti-wrinkle effects by reducing hyperkinetic facial lines.4,12 A multicenter, placebo-controlled, randomized clinical study showed an overall anti-wrinkle efficiency of 48.9% and a significant decrease in wrinkle depth in the argireline group.13 To minimize the risk of allergies, irritations, and other side effects, the peptide complex cream used three types of peptides at a lower concentration of 2% each. However, previous studies have shown that using a concentration of 10% for peptides or acetyl hexapeptide yields more significant results.8,9,13 This may also be one of the reasons why we did not observe significant results in wrinkle and pigmentation improvement. In this study, among the various indicators in FS-1200, the UV acne index was particularly significant. It demonstrated that the peptide complex cream exhibited significant improvement in acne starting from the second week. There appears to be no current literature on acne improvement by peptide complex creams, but one study has explored the effect of acetyl hexapeptide-8 on certain skin diseases by applying a gel cream containing 10% acetyl hexapeptide-8 to scarred or aging skin areas to treat skin conditions.14 The study found that the gel cream may improve the appearance of certain skin disorders. Acetyl hexapeptide-8 may help improve skin scarring, hidradenitis, and other conditions. Since acne is associated with excessive oil secretion from the sebaceous glands, acetyl hexapeptide-8 may alleviate facial acne by dampening local sympathetic excitation or reducing local muscle contraction, thus diminishing oil secretion. Although acetyl hexapeptide-8 may play a role in improving UV acne, this speculation requires larger and more in-depth studies in the future. Furthermore, the higher prevalence of acne in the age group of 45-55 years (typically less prone to acne) could be attributed to factors such as excessive sebum production and enlarged pores among these participants. It is possible that they had previously used skincare products inappropriately or lacked proper sun protection. However, after discontinuing their previous skincare products and using our product along with appropriate sunscreen, improvements in acne were observed.