Objective: The use of generic products is a solution to the increasing healthcare cost in Japan. The pharmaceutical companies are trying to develop several generic products suitable to patient’s taste. The contribution of pharmacist by selecting generic product to each patient and a collection of patient’s opinion for products may accelerate the development of generic products improved usability for patients and medical workers. The present study examined the storage of generic products of sennoside in pharmacies and the patient preference for selection of generic products in 2003 and 2016 in Kumamoto, Japan.Methods: Sennoside was selected as a model drug, since it developed several generic products for long period. The survey on storage of sennoside pharmaceutics and the questionnaire survey for its generic products to patients were conducted at ethical pharmacies. The appearance and the dissolution of sennoside from generic tablets were compared with original product, Pursennid.Results: Thirteen sennoside products were stored in 2003 and 2016. The number of pharmacies that stored generic products increased from 33 to 54% in 13 years. The largest number of patients preferred Pursennid in 2003. In contrast, two generic products were more preferred than Pursennid in 2016. Interestingly, the reasons for preferring products were almost the same between 2003 and 2016, and their majority was color and size of tablet. The generic products tend to have a thinner thickness and larger diameter than Pursennid. The most preferred generic product in 2016 showed a faster dissolution of sennoside than Pursennid. However, the use of generic products is mainly related to their tablet appearances due to unrelation between the pharmacological effect of sennoside and its dissolution in GI tract.Conclusion: In the development of generic products of sennoside, as well as quality, the appearance is an important factor.