Purchased NAC and it has a bad smell. Asked to send product back for another product as it is either a bad product or defected. Was told no. Was going to send the bottle back for replacement. Will never do business with them. At the end of the day many have the same product and all a company had is there level of customer service. Go with Source of Life vitamins. Source of Life has reputable manufacturing in USA AND they have always had excellent customer service. The only reason I went to Life Extension is because my uncle told me about them. My uncle said he is going to Source of Life now. All for a 9 dollar bottle. Penny wise. Pound foolish.