Most gym guys will agree, this is the best protein available. Don't believe me, read the reviews. I would also have to agree. It tastes great, mixes smooth and helps me recover.
Here's the breakdown of the product. (Vanilla)
Protein Blend(Whey Protein Isolates, Whey Protein Concentrate, Whey Peptides), Artificial Flavors, Lecithin, Acesulfame Potassium, Aminogen®, Lactase.
Whey Protein Isolates (WPI) has the fat, cholesterol, lactose removed resulting in significantly more pure protein in every serving. WPI is typically 90% or greater in protein content.
Whey Protein Concentrates (WPC) is a whole whey consisting of about 30, 60 or 80% protein with the rest being fat, cholesterol and lactose. The ON version would have to contain less of this since a serving typically contains 1 gram of fat and 2 grams of carbohydrates.
Whey Peptides (HYDRO WHEY[TM]) are peptides that are rapidly absorbed and quickly assimilated. The only thing faster would be free form amino acids.
Lecithin is an emulsifying agent that allows the ingredients within the protein shake to combine together into a smooth solution that doesn't separate out into clumps.
Acesulfame Potassium is an artificial sweetener.
Aminogen[R] is a patented enzyme system that liberates free form amino acids from protein containing foods and supplements. Controlled laboratory studies using Amingogen[R] have shown this compound to have the ability to release up to 42% more free form amino acids from intact proteins Amingogen[R] may also increase the anti-catabolic properties of more rapidly absorbed proteins such as whey by increasing the circulation time of amino acids inside the body.
ON's 100% Whey protein has always been very low lactose, the addition of Lactase enzymes helps to enhance the digestion and absorption of the four distinct whey proteins found in ON's 100% Whey Protein's Blend.
Below is a spreadsheet I put together of the amino acid content of this excellent protein.
"Optimum Nutrition's 100% Whey Protein better built. Better results." Joe Weider's Muscle & Fitness Sept. 2003: 204+. General OneFile. Web. 19 Jan. 2012.