Megestrol drug is a synthetic steroid progesterone, and it is used as an anti-plasma agent to treat advanced breast cancer or endometriosis. Although the liquid chromatographic method for measuring megestrol has advantages such as excellent accuracy and reproducibility, it has limitations such as long-time measure, high equipment cost, and maintenance and use. In this study, for determination of megestrol drug in solution using kinetic spectrophotometric method, we prepared a solution of Albizia Lebbeck Leaves-capped AgNPs utilizing sodium borohydride as a stabilizer sensor. The calibration curve was linear in the range of (0.1 to 10.0 µg L−1). The standard deviation of (3.0%), and detection limit of the method (0.2 µg L−1 in time 7 min, 385 nm) were obtained for Sensor level response Albizia Lebbeck Leaves-capped AgNPs with (95%) confidence evaluated. The observed outcomes confirmed the suitability recovery and a very low detection limit for measuring the megestrol drug. The method introduced to measure megestrol drug in real samples such as urine and blood was used and can be used for hospital samples. The chemical Albizia Lebbeck Leaves-capped AgNPs sensor made it possible as an excellent sensor with reproducibility. Manuscript profile