<![CDATA[Dry skin is a common dermatological problem caused by tropical climate exposure, pollution, and long-term use of synthetic moisturizers. Illipe butter (Shorea stenoptera) has potential as a natural emollient due to its saturated and unsaturated fatty acid content and stable melting point (36–39°C). This study aimed to determine the physical characteristics and physical stability of illipe butter body butter at five concentration variations (5%, 10%, 15%, 20%, and 25%) and to determine the optimal formula. This experimental study evaluated organoleptic properties, homogeneity, pH, viscosity, spreadability, adhesion, emulsion type, physical stability (six-cycle cycling test), and skin moisturizing effectiveness on five volunteers over 14 days. Data were analyzed using the Shapiro–Wilk normality test, Levene's homogeneity test, followed by One-way ANOVA/Tukey HSD or Kruskal–Wallis, and the Wilcoxon Signed-Rank test for paired pre- and post-cycling test data. Results showed that all formulas (F1–F5) were homogeneous and formed oil-in-water (O/W) emulsions both before and after the cycling test. The pH values ranged from 5.63–5.76 before and decreased to 4.95–5.46 after the cycling test (p<0.05). Viscosity increased after the cycling test, with F5 exceeding the instrument's measurement limit. Spreadability decreased significantly (p=0.001), while adhesion tended to decrease in F1–F3. All formulas effectively increased skin moisture (52–56% after 6 hours). The optimal formula was obtained at F3 (15% concentration), providing the best balance of viscosity, spreadability, and adhesion.]]>
