that it gives so I stick to products that don't have it.

Not too long ago C4 was busted with having large traces of it (above recommended levels).

I personally use ON Amino Energy. I've always trusted ON products and know multiple pro athletes that also use it. I've even talked with folks at USADA that have said it's one of a few clean products on the market. Another one is BPI. I've tried their preworkout but don't like the flavors as much.

The issues isn't as much with the manufacture as it is where they have the packaging done. A lot of Chinese and Mexico producers also produce illegal products that often find their way into the clean products from time to time.