What is whey protein isolate?
All whey protein is a by-product of cheese manufacturing.
If you're interested in learning more about how whey protein is produced, please refer to the FAQ.
Whey protein isolate (WPI) offers a richer, purer quality of protein when compared to a concentrate. Its protein content is marginally higher, it contains fewer calories, carbohydrates and fats, although we're only talking small numbers. Some people, mostly those in the bodybuilding community, swear by the advantages that whey isolate offers over a concentrate. The truth is both fractions are rapidly digesting proteins, so any added benefits will be negligible. That doesn't discount the fact that isolate remains a very popular selling supplement with dedicated fitness enthusiasts, especially those who are lactose intolerant or following a strict low calorie diet. In the bodybuilding world, WPI is a favourite for those cutting body fat. The lactose content in standalone WPI products is typically around 2.5 - 4%.
Due to its lower carbohydrate (lactose) and fat content, WPI is slightly more bio-available and faster at reaching muscles than a concentrate, making it a best choice post-workout. Taking it any other time of the day, except arguably in a pre-workout shake, in our opinion, is a waste. Unless you're following an ultra strict diet, a better through-the-day protein shake would be a mixed blend or even a whey protein concentrate.
Like WPC, WPI is also offered in both unflavoured and flavoured varieties. Unflavoured whey has an average protein content of around 90%. Flavoured variations reduce that by 4 - 7%. Taste-wise, unflavoured WPI is akin to bland watered down milk. Blended in water, the texture is thinner and whiter than plain WPC. The biggest difference between WPI and WPC is in price; WPI has always been more expensive due to its higher production cost. As this description is being written, comparing prices across several of the bulk suppliers, WPI on average costs 30% more than WPC. When you factor in the added marginal benefits, we would argue that a WPC would be a better "overall" option for the majority of people, but there is also the lactose factor to consider, too. Obviously, if lactose is a problem, WPI is the better option.
Would a WPI supplement suit me?
To answer the question adequately, it would really depend on your budget, how dedicated you are to your fitness, your tolerance to lactose, and the added benefits over a WPC. If you're obsessive about calories and maximising the best in the anabolic window post-workout, then WPI should be something to consider. It does contain lactose, albeit in very small quantities. If that's of concern to you, there are other options, including an option by Bulk Powders of an ultra-pure (97%) completely lactose free variant.
The bottom line
If you can afford it and you like the best of the best, give WPI a go.
If you're still not sure, you can find a supplement that will suit your goals with our protein finder.