Chenopodium quinoa is an Andean phytoresource with great genetic variety and that has high agronomic-nutritive value, although the content of saponin gives a bitter taste that limits its commercialization; however, saponin can be used in other uses. The present study reports the water used to wash quinoa as a source of saponin and its use as an insecticide. The quantification of saponin was performed using the afrosimetric method. The non-hydrolyzed extracted saponin was identified by thin layer chromatography. To evaluate the birth rate of D. melanogaster individuals, they were exposed to different concentrations of saponin: 0.1%, 0.4%, 0.7% and 0.9%; as well as positive (borax) and negative controls. The electrophoresis of proteins from the salivary glands and intestine of larvae in the third stage of D. melanogaster shows evident differences in protein expression between (T) 0.4% and the rest of the treatments. In conclusion, saponin can be considered as an agent that hinders the larval survival of D. melanogaster because the response to it will vary according to the concentration used. It is advisable to use concentrations higher than 0.9% so that mortality is greater than 40% of individuals.