This paper studies how the influencing factors of attitudes, subjective norms, and perceived behavioral control can influence the customers' purchase intention. In this paper, purchasing intention is indirectly influenced by consumer's health cautions, knowledge, social communications and brands through attitude; influenced by the reference group through subjective norms; and finally, indirectly influenced by price, availability, and quality through perceived behavioral control. To evaluate the relationship between attitude, subjective norms and perceived behavioral control toward customers' purchasing intention, qualitative research was conducted to orientate and to measure the impact of the influences above. The aim of this paper is to illustrate the research's empirical findings, conducted in Hanoi during 2019 from April 1st to April 30th, in order to examine the framework and the proposed research theories. The results of the research demonstrate that the factor "Brand" indirectly influences the consumers' purchase decision toward dietary supplements through “Attitude”, “Availability” and “brand”. Especially, in the case of dietary supplements, the subjective norm does not influence purchase intention.
Volume 12 | 03-Special Issue