For my sports and weigh training supplementation I like NOW Sports Products.
I came here looking for some discussion about the recent report of heavy metals and contaminants in protein powders, even in some of the better brands like NOW.
I subscribed to a pay service to get lab testing results of supplements for several years (it might have been Consumerlabs, so long ago I forget, ha). Anyway NOW brand products were always at, or near the top of the list not only for purity, but for verified amount of active ingredient.
Basically I learned that what I read on the NOW label is as close to what's inside as any of these companies can seem to get, in what is an unregulated industry.
I always get NOW supplements, it's basically buy it and I don't worry. I take or have taken Niacin, fish oils and multis, melatonin, and protein powders and creatine.