Ethanol extract of butterfly pea flower contains anthocyanin compounds that useful as hair growth promoters and reduce hair loss. The extract was formulated into a nanoemulsion using isopropyl myristate as the oil phase to increase the surface area of contact, allowing the active compounds to better penetrate the skin and preventing agglomeration of the globules during storage. The study aimed to investigate the stability and percutaneous penetration profile of the nanoemulsion with varying concentrations of isopropyl myristate. The nanoemulsion was prepared by mixing isopropyl myristate as the oil phase at concentrations of 2.5% (F1), 4.5% (F2), and 6.5% with the aqueous phase containing PEG 400, Cremophor RH 40, sodium benzoate, and the ethanol extract of butterfly pea flower. Accelerated stability testing was conducted at 40°C ± 2°C and 75% ± 5% RH for 4 weeks, and were evaluated for organoleptic properties, nanoemulsion type, pH, density, viscosity, globule size, polydispersity index, and zeta potential. In vitro percutaneous penetration was assessed using a Franz diffusion cell, and the penetrated anthocyanin content was measured using a UV-Vis spectrophotometer at 559 nm for 8 hours. The accelerated stability testing showed no changes in odor or texture, and the nanoemulsions remained in the oil-in-water (O/W) type. The results of stability testing on F1, F2, and F3 showed the values of pH, specific gravity, viscosity, globule size, polydispersity index and zeta potential showed no significant difference (p>0.05) in conditions before and after storage. The penetration flux value of in F1 was 16.43±7.87 %/cm², F2 was 24.62±14.11 %/cm² and F3 was 32.30±32.23 %/cm². The results indicated that emulsions containing 2.5% (F1), 4.5% (F2), and 6.5% isopropyl myristate were stable and showed an increase in percutaneous penetration. However, statistical analysis using One Way ANOVA revealed that there was no significant difference between F1, F2, and F3.