In order to load metformin in a nano formula and evaluate the produced nano form towards cancer cells, metformin was loaded on natural carrier coconut oil. The formed metformin-loaded coconut oil nanoemulsion was characterized by Zeta potential, particle size, drug content, drug release, and drug stability. The formed nanoemulsion was evaluated towards MCF-7, HepG2, and HCT-116 cell lines. Cell cycle analysis and apoptosis mechanism were studied. The nanoemulsion was created using deionized water, 1.5% Span 20, 1.5% Tween 80, 1.5% coconut oil, and 0.5% Metformin in an ultrasonicator to produce a homogenous solution. The anticancer activities of the metformin-loaded coconut nanoemulsion were highly improved compared to non-formulated metformin with IC50s of 8.3 ± 0.1 mg/ml, 12 ± 1.5 mg/ml, 2.685 ± 0.3 mg/ml for MCF-7, HepG2, and HCT-116 cell lines, respectively. There was a 76.5 ± 2.3 and 78.3 ± 3.2% increase in the number of apoptotic cells of MCF-7 and HepG2 cells after nanoemulsion treatment. This formula may be considered a new anticancer medication.