Background: Various types of external breast tissue expanders have been found to be effective for aesthetic breast augmentation. However, their use has been limited when compared with implant-based breast augmentation due to the burdensome nature of their application. This article reports the possibility that external breast tissue expanders may be applied safely and effectively with higher pressure and shorter application time. Methods: The participants comprised patients who desired breast augmentation using the EVERA-RAPHA device between January 2020 and March 2020. A double-blinded prospective study was conducted on two groups of eight patients each, with either 60 mmHg or 100 mmHg of pressure applied. Standardized photographs were taken and blinded measurements of volume and circumference were made. The Mann-Whitney and paired t-tests were conducted. Results: Sixteen patients were evaluated after 1 month of treatment. The women in groups 1 and 2 (60 mmHg and 100 mmHg, respectively) used EVERA-RAPHA for 15.400± 0.704 and 15.300±0.477 minutes per day, respectively. The mean volume increases in groups 1 and 2 were 39.000±42.526 cc and 27.700±20.260 cc, respectively. No patients dropped out of the study. All patients reported that the device was tolerable. Mild bruising was found in 62.5% of the patients in group 2. Conclusions Breast augmentation using external tissue expanders can be a safe, effective, and practical option. Pressures of 60 mmHg or 100 mmHg can be safely applied for a shorter duration. Larger studies are needed to further confirm our findings.