This thread discusses the content article: Isopure (Nature's Best)

In grouping the formats (container sizes) for the Isopure pages, I stumbled upon and solved the mystery of the various confusing names for these whey protein isolates. Let me explain...

First, let's note that all of their names begin with "Perfect".

Now, the most "basic" one is called Isopure. Per serving, this has 300 calories, 50 g of protein, and 25 g of total carbs. This comes in the formats of 20 packs, and 8.8 lb.

Then, we have Isopure Whey Protein Isolate. Yes, the one I described above is also a WPI, however, it is a different product. This WPI comes in ONLY the 3 lb size, and has 110 calories, 26 g protein, and 0 g carbs per serving. It's also unflavoured.

Next, there is Isopure Zero Carb, or Zero Carb Isopure, whichever way you want to call it. (Unfortunately, the Nature's Best website doesn't work at the time of this writing, so I can't check the official name.) This has, per serving, 210 calories, 50 g of protein, and 0 g of carbs. By the magnitudes of these ingredients, it seems like it's the same as the preceding one I just described, but in a larger serving size, right? However, it really is a different product, which is obvious from the names on the packagings. This comes in 1 lb, 3 lb, and 7.5 lb sizes. One more point of confusion is that what some stores call Isopure, is, in fact, Zero Carb Isopure.

Then there is Isopure Low Carb, which has 210 calories, 42 g protein, and 10 g carbs, and comes in 20 packs. Note that this is not the same as Low Carb Isopure, which is really the same as Zero Carb Isopure, but has 3 g of total carbs including 2 g of fibre, and comes in only the Dutch Chocolate flavour. (Bodybuilding.com tells you that "The Dutch Chocolate flavor [of Zero Carb Isopure] is in the Low-Carb version of Isopure, and has 3g of carbs." However, this is not strictly true, because going by the amount of protein, it's actually much closer to Zero Carb Isopure.) Are you confused yet?

Next up is Natural Isopure, which has 240 calories, 50 g protein, and 7 g carbs (5 g sugar). It's called "Natural" because it is sweetened with cane sugar rather than artificial sweeteners. It comes in just the 3 lb container size.

At least the RTD's are simpler. There's just Isopure Plus, and Isopure Plus Zero (0) Carb.