I did much research getting a good quality vitamin b complex supplement. I researched and compared other stores online as well. I checked the quality of the ingredients and compared it to top brands that is known on the Internet. when I purchased products like this, I do my research. I am only gonna take the best products ,the safest products, and. and that is well within my budget. having a budget for supplements to better my health doesn't mean it has to be the lowest quality this product is excellent.for myself personally it didn't give me an upset stomach or make me nauseous.