Pressure injuries are a common kind of skin lesion that may be difficult to treat. The objective of this study was to analyze the effect of hydrogel enriched with alginate, fatty acids, and vitamins A and E in the treatment of pressure injuries. This case series with 12-week follow-up included applying daily dressings with hydrogel, maintaining a photographic record, using planimetry to calculate the lesion area, and classifying the healing process using the Pressure Ulcer Scale for Healing (PUSH). In addition, exudate collection from the ulcers was performed in the beginning and after 12 weeks of treatment to determine the dosage of metalloproteinase 9 (MMP9) and tissue inhibitor of metalloproteinase 1 (TIMP1). Of the 13 patients included in the study, 2 died and 11 were monitored for 12 weeks. Only 1 patient showed full wound healing, but all patients showed a significant 12.19% (p = .023) reduction in the lesion area. The PUSH score was also significantly reduced from 15.9 to 10.54 (p = .0052). Relative to the dosage of metalloproteinase and its inhibitor, there was a reduction in the level of MMP9 and there was no change in the level of TIMP1. This study showed that hydrogel enriched with alginate, fatty acids, and vitamins A and E provided promising results for the treatment of pressure injuries by reducing the lesion area, the general PUSH score, and the amount of MMP9 in the wounds' microenvironment.