Extraction efficacy, stability assessment and seasonal variation of bioactive 'gymnemagenin' in Gymnema sylvestre

► Effect of drying techniques, extraction methods, storage conditions and seasons on gymnemagenin were observed in Gymnema sylvestre. ► Shade drying and acid-base hydrolysis is the best and economical method for obtaining the highest yield of gymnemagenin. ► The compound exhibited rapid deterioration on storage in polystyrene vials kept in light. ► Least deterioration was observed in borosilicate glass containers in dark conditions. ► Summer was found to be the best season for harvesting the plant.