Yeah you have to careful with supplements. There are alot of disreputable labs out there. Then you hear horror stories of poisons in supplements and generics coming from China. the fda can't monitor all of them. My brother and sister in law are both pharmacist and owned there own pharmacy. they did alot of research so they could sell supplements they trusted. I can't remember them all but Nature Made was one and it is widely sold. That is what I buy.
I know there is controversy about which forms of fish oil can be absorbed and all that. A pdoc that my other brother brought my nephew too prescribed some form that came in like a jelly. I can't remember the brand though.