Reduced Injection Site Pain with Altered pH in 24-h Reconstituted Botulinum Toxin: Findings from a Randomized Controlled Study on Cosmetic Applications.

[BACKGROUND] Botulinum toxin (BTX) injections are widely recognized for many cosmetic applications, but still commonly encounter a challenge: injection site pain (ISP). This discomfort can impact the overall patient experience and satisfaction, highlighting a need for innovative solutions to this problem.

[OBJECTIVE] This randomized controlled study aimed to determine whether adjusting the pH levels in a 24-h reconstituted botulinum toxin can serve as a strategy to mitigate ISP.

[METHODS] A controlled trial involving 24 volunteers was executed. Participants received incobotulinum toxin A. One side of each participant's face was treated with fresh toxin, while the other received a 24-h reconstituted version. Pain perceptions post-injection were assessed using the visual analogue scale (VAS).

[RESULTS] pH values of the fresh toxin were more acidic (6.17) than the 24-h reconstituted toxin (7.17). Out of 24 patients, 13 reported reduced ISP with the 24-h reconstituted toxin. The mean VAS score for the fresh toxin was 5.92, in contrast to 4.17 for the reconstituted toxin, indicating a significant difference (p<0.01).

[CONCLUSION] Limitations include the use of a VAS and a relatively small sample size. Altering the pH of BTX demonstrates potential in ISP reduction. However, broader, large-scale investigations are important for comprehensive validation.

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