You might remember 2015’s Best Protein Powder and 2015’s Best Dog Food. Reviews.com has published a new study where they tested 309 different pre-workout supplements to find the best product on the market. We’ll give you the very abridged version and let you read the article here for yourself. Essentially, they used a filtration system to narrow down the big number through process of elimination. They would remove anything with banned/potentially harmful substances, then proprietary blends, then a certain amount of caffeine, then any artificial flavors/colors to figure out the cleanest product.