The current study aims to investigate the safety and efficacy of using calcium hydroxyapatite (CaHA) versus CaHA associated with hyaluronic acid (HA) for forehead volume replacement and contour restoration without forehead irregularities. This interventional study involved 132 participants in a two-arm, parallel, double-blind trial for forehead treatment using the supraperiosteal technique. Group A received CaHA, and Group B received a combination of CaHA and HA as filler materials. Follow-up assessments occurred at 30 and 180 days, incorporating the 5-point Global Aesthetic Improvement Scale (GAIS) and photographic analysis for forehead volume replacement, contour restoration, and without forehead irregularities. Safety assessments included monitoring adverse events, particularly nodules. The study included all 132 enrolled patients who completed the trial. Applying CaHA in combination with HA resulted in a statistically significant improvement in both GAIS scale scores and the reduction of forehead irregularities. The total incidence of nodules was 3.7%. Group A had four times more occurrences of nodules than Group B. Furthermore, Group B exhibited lower rates of forehead irregularities following the treatment compared to Group A. The supraperiosteal application of CaHA and HA for forehead treatment demonstrates superior efficacy in addressing signs of aging compared to the isolated use of CaHA.